Corrected path to mapping libraries.
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1 1***********************************************************************
2  *                                                                     *
3  *   CERN                                                              *
4  *                                                                     *
5  *   W5051 PDFLIB                                         2000.04.17   *
6  *                                                                     *
7  *   ---------------------------------------------------------------   *
8  *                                                                     *
9  *      PDFLIB: Nucleon, Pion and Photon Parton Density Functions      *
10  *                      and alpha(s) Calculations                      *
11  *                                                                     *
12  *                           User's Manual                             *
13  *                                                                     *
14  *                           Version 8.04                              *
15  *                                                                     *
16  *                                                                     *
17  *                     H. Plothow-Besch/CERN-PPE                       *
18  *                                                                     *
19  *                         CH-1211 Geneva 23                           *
20  *               E-mail address: plothow@mail.cern.ch                  *
21  *                    Tel.: +41 - 22 - 767 39 80                       *
22  *                                                                     *
23  *   A complete manual in PostScript format exists on a separate file  *
24  *     Requests can be addressed to the CERN Program Library Office    *
25  *                                                                     *
26  *                   Copyright by H. Plothow-Besch                     *
27  *                                                                     *
28  *                            Abstract                                 *
29  *                                                                     *
30  *       This document describes an integrated package of Parton Den-  *
31  *  sity Functions called PDFLIB which has been added to the CERN      *
32  *  Program Library Pool W999 and is labelled as W5051. In this pack-  *
33  *  age all the different sets of parton density functions of the      *
34  *  NUCLEON, the PION and the PHOTON which are available today (about  *
35  *  100 different sets) have been put together. All these sets have    *
36  *  been combined in a consistent way such that they all have similar  *
37  *  calling sequences and no external data files have to be read in    *
38  *  anymore. A default set has been prepared, although those prefering *
39  *  their own set or wanting to test a new one may do so within the    *
40  *  package. The selection mode, the program parameters as well as     *
41  *  the possibilities to modify the defaults and to control errors     *
42  *  occured during execution are described.                            *
43  *                                                                     *
44  *       The package offers as well a program to calculate the strong  *
45  *  coupling constant alpha(s) to first or second order (default).     *
46  *  The correct Lambda(QCD) associated to the selected set of struc-   *
47  *  ture functions and the number of allowed flavours with respect to  *
48  *  the given Q**2 is automatically used in the caculation. For those  *
49  *  structure functions where the evolution has been performed to      *
50  *  leading order only, an alpha(s) value fixed to first order is re-  *
51  *  turned.                                                            *
52  *                                                                     *
53  *       The package is written in standard FORTRAN-77 and is avai-    *
54  *  lable on all CERN system areas.                                    *
55  *                                                                     *
56  *                                                                     *
57  *                                                                     *
58  *        Submitter:   H. Plothow-Besch/CERN-PPE                       *
59  *        Language:    FORTRAN 77                                      *
60  *        Library:     PDFLIB                                          *
61  *                                                                     *
62  *                                                                     *
63  *                                                                     *
64  *                                                                     *
65  *                                                                     *
66  *                                                                     *
67  *                                                                     *
68  *                                                                     *
69  ***********************************************************************
70 1***********************************************************************
71  *                                                                     *
72  *                                                                     *
73  *   _______________________________________________________________   *
74  *   |                                                             |   *
75  *   |  PDFLIB - User's Manual                                     |   *
76  *   |                                                             |   *
77  *   |  CERN Computer Program Library entry W5051                  |   *
78  *   |                                                             |   *
79  *   |  Copyright CERN, Geneva 1990, 1991, 1992, 1993, 1994, 1995  |   *
80  *   |  Copyright CERN, Geneva 1996                                |   *
81  *   |                                                             |   *
82  *   |  Copyright and any other appropriate legal protection of    |   *
83  *   |  these computer programs and associated documentation re-   |   *
84  *   |  served in all countries of the world.                      |   *
85  *   |                                                             |   *
86  *   |  These programs or documentation may not be reproduced      |   *
87  *   |  and/or redistributed by any method without prior written   |   *
88  *   |  consent of the Director-General of CERN or his delegate.   |   *
89  *   |                                                             |   *
90  *   |  Permission for the scientific usage of any programs des-   |   *
91  *   |  cribed herein is granted apriori to those scientific in-   |   *
92  *   |  stitutes associated with the CERN experimental program or  |   *
93  *   |  with whom CERN has concluded a scientific collaboration    |   *
94  *   |  agreement.                                                 |   *
95  *   |                                                             |   *
96  *   |  Commercial utilisation requires explicit a priori per-     |   *
97  *   |  mission from CERN and will be subjected to payment of a    |   *
98  *   |  licence fee.                                               |   *
99  *   |                                                             |   *
100  *   |  These statements are without prejudice to any rights that  |   *
101  *   |  third parties may hold in these programs.                  |   *
102  *   |                                                             |   *
103  *   |                                                             |   *
104  *   |  Requests for information should be addressed to:           |   *
105  *   |                                                             |   *
106  *   |        CERN Computer Program Library Office                 |   *
107  *   |        CERN-CN Division                                     |   *
108  *   |        CH-1211 Geneva 23                                    |   *
109  *   |        Switzerland                                          |   *
110  *   |        Tel. +41 22 767 4951                                 |   *
111  *   |        Fax. +41 22 767 7155                                 |   *
112  *   |        Electronic Mail address:                             |   *
113  *   |                                                             |   *
114  *   |        Internet:      cernlib@cern.ch                       |   *
115  *   |_____________________________________________________________|   *
116  *                                                                     *
117  *                                                                     *
118  *                                                                     *
119  *                                                                     *
120  *                                                                     *
121  *                                                                     *
122  *                                                                     *
123  *                                                                     *
124  *                                                                     *
125  *                                                                     *
126  *                                                                     *
127  *                                                                     *
128  *                                                                     *
129  *                                                                     *
130  *                                                                     *
131  *                                                                     *
132  *                                                                     *
133  *                                                                     *
134  *                                                                     *
135  *                                                                     *
136  *                                                                     *
137  *                                                                     *
138  ******************************** - 1 - ********************************
139 1***********************************************************************
140  *                                                                     *
141  *      Table of Contents                                              *
142  *                                                               page  *
143  *                                                                     *
144  *      PROGRAM SUMMARY .......................................... 3   *
145  *                                                                     *
146  *      PDFLIB : New version 8.00 ................................ 4   *
147  *                                                                     *
148  *  0.  Major Differences compared to earlier Versions ........... 4   *
149  *      0.1  The actual Version 8.00 wrt Version 7.00 ............ 4   *
150  *      0.2  Version 7.00 wrt Version 6.00 ....................... 5   *
151  *      0.3  Version 6.00 wrt Version 5.00 ....................... 5   *
152  *      0.4  Version 5.00 wrt Version 4.00 ....................... 6   *
153  *      0.5  Version 4.00 wrt Version 3.00 ....................... 6   *
154  *      0.6  Version 3.00 wrt Version 2.00 ....................... 6   *
155  *      0.7  Version 2.00 wrt Version 1.00 ....................... 7   *
156  *                                                                     *
157  *  1.  The Library of Parton Densities: PDFLIB ................. 10   *
158  *      1.1  Introduction ....................................... 10   *
159  *      1.2  Structure Functions of the Nucleon ................. 12   *
160  *      1.3  Structure Functions of the Pion .................... 12   *
161  *      1.4  Structure Functions of the Photon .................. 12   *
162  *      1.3  The Calling Sequence: PDG Format ................... 14   *
163  *      1.4  The Library PDFLIB ................................. 14   *
164  *      1.5  Calculations of the Strong Coupling Constant alpha(s)15   *
165  *                                                                     *
166  *  2.  Applications of the Parton Densities Package PDFLIB ..... 10   *
167  *      2.1  Parameter Setting and Selection of Sets ............ 10   *
168  *      2.2  The Calling Sequence: PDFLIB Format ................ 12   *
169  *      2.3  The Calling Sequence: PDG Format ................... 14   *
170  *      2.4  Error Handling ..................................... 14   *
171  *      2.5  Features ........................................... 15   *
172  *      2.6  How to find PDFLIB ................................. 18   *
173  *                                                                     *
174  *  3.  PION and PHOTON Parton Densities                          18   *
175  *                                                                     *
176  *  4.  alpha(s) Calculation                                      18   *
177  *                                                                     *
178  *  5.  Conclusions                                               19   *
179  *                                                                     *
180  *  6.  Acknowledgements                                          21   *
181  *                                                                     *
182  *  7.  References                                                32   *
183  *                                                                     *
184  *      Appendix                                                  22   *
185  *      A : Example of how to use PDFLIB ........................ 22   *
186  *      B : List of subprograms and COMMON blocks in PDFLIB            *
187  *          which are relevant to the user ...................... 25   *
188  *      C : Complete list of subprograms in PDFLIB .............. 26   *
189  *                                                                     *
190  *      List of Tables                                            34   *
191  *                                                                     *
192  *                                                                     *
193  *                                                                     *
194  *                                                                     *
195  *                                                                     *
196  *                                                                     *
197  *                                                                     *
198  *                                                                     *
199  *                                                                     *
200  *                                                                     *
201  *                                                                     *
202  *                                                                     *
203  *                                                                     *
204  *                                                                     *
205  *                                                                     *
206  ******************************** - 2 - ********************************
207 1***********************************************************************
208  *                                                                     *
209  *  PROGRAM SUMMARY                                                    *
210  *                                                                     *
211  *                                                                     *
212  *  Titel of Program : PDFLIB, version 8.00                            *
213  *                                                                     *
214  *  Catalogue number : W5051 in the CERN Computer Program Library      *
215  *                                                                     *
216  *  Program obtainable from : CERN Computer Program Library Office     *
217  *                                                                     *
218  *  Computer for which the program is designed and others on which it  *
219  *  has been tested:                                                   *
220  *  Computer : IBM 3090, VAX, IBM-RISC, DECS, SUN, APOLLO, HP-UX,      *
221  *             Silicon Graphics, NEXT, CDC, CRAY, IBM-PC               *
222  *                                                                     *
223  *  Operating systems : VM/CMS, VAX/VMS, Unix, Windows NT              *
224  *                                                                     *
225  *  Programming language used : FORTRAN 77, program is available in    *
226  *                              the CVS format                         *
227  *                                                                     *
228  *  Number of lines in distributed progam,                             *
229  *  including test data, etc : 192 000                                 *
230  *                                                                     *
231  *  Memory required,                                                   *
232  *  including testprograms and some documentation : 25 Mbytes          *
233  *  (Source code: 10 Mbytes,  Library: 10 Mbytes)                      *
234  *                                                                     *
235  *  No. of bits in a word : 64                                         *
236  *                                                                     *
237  *  Peripherals used : line printer (optional)                         *
238  *                                                                     *
239  *  Keywords : parton density functions, structure functions, W5051,   *
240  *             nucleon-, proton-, pion-, photon density parametrisa-   *
241  *             tions, Altarelli-Parisi equation, strong coupling       *
242  *             constant alpha(s)                                       *
243  *                                                                     *
244  *  Nature of physical problem :                                       *
245  *  All theoretical calculations of cross sections involving the       *
246  *  hadronic structure of the incoming particles, i.e. protons, pions  *
247  *  or photons, use the parton density at a given longitudinal momen-  *
248  *  tum X of the parton and at a given momentum transfer Q**2. There   *
249  *  is a variety of parametrisations available, but each of them has   *
250  *  its own structure for input and/or output.                         *
251  *                                                                     *
252  *  Method of solution :                                               *
253  *  Collection of all available parton density parametrisations and    *
254  *  application in an identical format for all of them, regardless of  *
255  *  the author's convention or of the particle type.                   *
256  *                                                                     *
257  *  References :                                                       *
258  *  [1] H. Plothow-Besch, 'PDFLIB: Structure Functions and alpha(s)    *
259  *      Calculations', User's Manual - Version 1.00, W5051 PDFLIB,     *
260  *      1991.03.21, CERN-PPE.                                          *
261  *  [2] H. Plothow-Besch, 'PDFLIB: a library of all available parton   *
262  *      density functions of the nucleon, the pion and the photon and  *
263  *      the corresponding alpha(s) calculations',                      *
264  *      Comp. Phys. Comm. 75 (1993) 396-416.                           *
265  *  [3] H. Plothow-Besch, 'The Parton Distribution Function Library',  *
266  *      Int. J. Mod. Phys. A10 (1995) 2901-2910.                       *
267  *                                                                     *
268  *                                                                     *
269  *                                                                     *
270  *                                                                     *
271  *                                                                     *
272  *                                                                     *
273  *                                                                     *
274  *                                                                     *
275  ******************************** - 3 - ********************************
276 1***********************************************************************
277  *                                                                     *
278  *  0.  Major Differences compared to earlier Versions                 *
279  *                                                                     *
280  *                                                                     *
281  *  0.1  The actual Version 7.09 wrt Version 6.00:                     *
282  *                                                                     *
283  *                                                                     *
284  *     The following major changes compared to version 6.00 of PDFLIB  *
285  *  have been implemented:                                             *
286  *                                                                     *
287  *  Several NUCLEON structure function sets have been added:           *
288  *                                                                     *
289  *    - the NLL sets A of Martin Roberts and Stirling (MRS-A lQ) for   *
290  *      low Q**2 of May 1995 in the DIS and the MS_bar renormalisation *
291  *      schemes, as well as the NLL sets A' for 6 different values of  *
292  *      alpha_s (MRS-Ap-150, MRS-Ap-201, MRS-Ap-266, MRS-Ap-344,       *
293  *      MRS-Ap-435, MRS-Ap-542), the J and J' sets (MRS-J and MRS-Jp)  *
294  *      of May 1996 which include the high p_T-jet data of the TEVA-   *
295  *      TRON, and the latest MRS sets R1 to R4 (MRS-R1, MRS-R2,        *
296  *      MRS-R3, MRS-R4) of May 1996 with grid data as well as in its   *
297  *      parametrized form (MRS-R1-F) and (MRS-R2-F);                   *
298  *    - version 4 of the CTEQ group of June 1996 as NLL parametrisa-   *
299  *      tion in the $\overline{MS}$ as well as in the DIS renormalisa- *
300  *      tion scheme and as LO (CTEQ4M, CTEQ4D, CTEQ4L), the CTEQ4M set *
301  *      for 5 different values of alpha_s (CTEQ4A1, CTEQ4A2, CTEQ4A3,  *
302  *      CTEQ4A4, CTEQ4A5), a set which includes the high $p_T$-jet     * 
303  *      data of the TEVATRON (CTEQ4HJ), and a set for low Q**2         *
304  *      (CTEQ4lQ);                                                     *
305  *    - the new sets of Gl"uck, Reya, Stratmann and Vogelsang as LO    *
306  *      and of August 1995 as NLL in the MS_bar renormalisation scheme *
307  *      of polarized parton distributions in a 'standard' and a        *
308  *      'valence' fit version (GRSVpolS, GRSVpolV). A special COMMON   *
309  *      block (COMMON /GRSVA1/ A1P, A1N, A1D) transmits directly the   *
310  *      spin asymmetries of the proton, the neutron and the deuteron.  *
311  *                                                                     *
312  *  A NEW GROUP of authors of PHOTON structure function sets has been  * 
313  *  added:                                                             *
314  *                                                                     *
315  *    - the 4 old LO sets of Schuler and Sjostrand of March 1995, as   *
316  *      well as the 4 LO sets of their revised version of May 1996     *
317  *      (SaS-G-1D, SaS-G-1M, SaS-G-2D, SaS-G-2MD).                     *
318  *                                                                     *
319  *  Several new PHOTON structure function sets have been added:        *
320  *                                                                     *
321  *    - the recent LO set of Gl"uck, Reya and Stratmann of February    *
322  *      1996 (GRS-G);                                                  *
323  *    - the recent LO and HO sets of Gordon and Storrow of August 1996 *
324  *      (GS-G-LO, GS-G-HO).                                            *
325  *                                                                     *
326  *  To take into account the need for more input parameters for parton *
327  *  densities of the photon a NEW SUBROUTINE STRUCTP has been added    *
328  *  which should be called instead of STRUCTM in case of applications  *
329  *  of the photon.                                                     *
330  *                                                                     *
331  *  Several CORRECTIONS to existing structure function sets have been  *
332  *  performed:                                                         *
333  *                                                                     *
334  *    - to account for heavy quark contributions (c and b) in the      *
335  *      nucleon parton densities of Gl"uck, Reya and Vogt (GRV94),     *
336  *      now automatically the OLD GRV parton densities of 1992 are     *
337  *      called for c and b quarks as advised in their paper;           *
338  *    - corrections for LINNUX-systems suggested by V. Balashov have   *
339  *      been taken into account.                                       *
340  *                                                                     *
341  *  A BUG in the data tables for the parton densities of the photon of *
342  *  the set of Aurenche, Fontannaz and Guillet (AFG-G) has been fixed. *
343  *                                                                     *
344  ******************************** - 4 - ********************************
345 1***********************************************************************
346  *                                                                     *
347  *     More details can be found on the next pages of this updated     *
348  *  User's Manual.                                                     *
349  *                                                                     *
350  *     The response from the Physics community has been very satis-    *
351  *  factory, which is encouraging us to keep up-to-date with the       *
352  *  latest developments in this area. The author will be pleased to    *
353  *  learn about new parton density functions, as well as to receive    *
354  *  suggestions to improve both, the usage and the documentation.      *
355  *  Please send your comments to plothow@mail.cern.ch.                 *
356  *                                                                     *
357  *                                                                     *
358  *                                                                     *
359  *                                                                     *
360  *  0.2  Version 6.00 wrt Version 5.00:                                *
361  *                                                                     *
362  *                                                                     *
363  *     The following major changes compared to version 5.00 of PDFLIB  *
364  *  have been implemented:                                             *
365  *                                                                     *
366  *  Several NUCLEON structure function sets have been added:           *
367  *                                                                     *
368  *    - the NLL sets A' and G of Martin, Roberts and Stirling (MRS-Ap) *
369  *      and (MRS-G) of February 1995 with grid data as well as in its  *
370  *      parametrized version (MRS-Ap-F) and (MRS-G-Fit),               *
371  *    - the version 3 of the CTEQ group of October 1994 as NLL parame- *
372  *      trisation in the MS_bar as well as in the DIS renormalisation  *
373  *      scheme and as LO (CTEQ3M, CTEQ3D, CTEQ3L),                     *
374  *    - the new sets of GRV of November 1994 as NLL in the MS_bar as   *
375  *      well as in the DIS renormalisation scheme and as LO GRV        *
376  *      (GRV94-MS, GRV94DI, GRV94-LO).                                 *
377  *                                                                     *
378  *  A NEW group of PHOTON structure function sets have been added:     *
379  *                                                                     *
380  *    - the six NLL sets of the WHIT group (WHIT1-G to WHIT6-G).       *
381  *                                                                     *
382  *  Please note that as new the default set the MRS set (G) has been   *
383  *  chosen (NPTYPE = 1, NGROUP = 3, NSET = 41).                        *
384  *                                                                     *
385  *                                                                     *
386  *                                                                     *
387  *                                                                     *
388  *  0.3  Version 5.00 wrt Version 4.00:                                *
389  *                                                                     *
390  *                                                                     *
391  *     The following major changes compared to version 4.00 of PDFLIB  *
392  *  have been implemented:                                             *
393  *                                                                     *
394  *  NUCLEON structure function sets have been added:                   *
395  *                                                                     *
396  *    - the NLL set A of Martin, Roberts and Stirling (MRS-A) and the  *
397  *      parametrized version (MRS-A-Fit)                               *
398  *  PHOTON structure function sets have been added:                    *
399  *    - the NLL set of Aurenche, Fontannaz and Guillet (AFG-G).        *
400  *                                                                     *
401  *                                                                     *
402  *                                                                     *
403  *                                                                     *
404  *  0.4  Version 4.00 wrt Version 3.00:                                *
405  *                                                                     *
406  *                                                                     *
407  *     The following major changes compared to version 3.00 of PDFLIB  *
408  *  have been implemented:                                             *
409  *                                                                     *
410  *  NUCLEON structure function sets have been updated or added:        *
411  *                                                                     *
412  *                                                                     *
413  ******************************** - 5 - ********************************
414 1***********************************************************************
415  *                                                                     *
416  *    - the updated NLL sets of Martin, Roberts and Stirling (MRS) of  *
417  *      November 1992, the sets S0', D0' and D-' in the MSbar as well  *
418  *      as the sets S0', D0' and D-' in the DIS renormalisation        *
419  *      scheme. Please note that the previous S0, D0 and D- sets have  *
420  *      been retracted by the authors. The new MRS(H) set in both      *
421  *      schemes have also been added,                                  *
422  *    - the NLL and LO sets of the CTEQ collaboration (CTEQ) in its    *
423  *      parametrised form of January 1993. These are the sets 1M, 1MS  *
424  *      and 1ML in the MSbar, the set 1D in the DIS renormalisation    *
425  *      scheme and the LO set 1L,                                      *
426  *    - the new NLL sets A and B of Berger and Meng (BM) of            *
427  *      February 1993 with special gluon distributions, and finally    *
428  *    - the new NLL and LO sets of the CTEQ collaboration (CTEQ) in    *
429  *      its parametrised form of August 1993. These are the sets 2M,   *
430  *      2MS, 2MF and 2ML in the MSbar, the set 2D in the DIS renorma-  *
431  *      lisation scheme and the LO set 2L. The revised CTEQ2 version,  *
432  *      CTEQ2p, of November 1993 is recommended by the authors.        *
433  *                                                                     *
434  *  Please note that the default set has been put to the GRV set HO    *
435  *  (NPTYPE = 1, NGROUP = 5, NSET = 3 / former MODE = 72).             *
436  *                                                                     *
437  *  The MOST DRASTICAL change of the package has been, however, the    *
438  *  NEW FORMAT of PARAMETER SETTINGS. Instead of using only ONE para-  *
439  *  meter (MODE) to select a set of parton density functions (PDF),    *
440  *  each PDF set is now identified by THREE parameters. These are      *
441  *  NPTYPE, NGROUP and NSET, for PARTICLE TYPE (Nucleons, Pions or     *
442  *  Photons) AUTHOR GROUP (f.ex. MRS, CTEQ, GRV, etc) and the PARAME-  *
443  *  TRISATION SET within the group. Therefore the user should provide  *
444  *  THREE parameters (NPTYPE, NGROUP, NSET) to the subroutine PDFSET,  *
445  *  each time a PDF set shall be selected. But to make life nice and   *
446  *  easy, it is also possible to select a PDF set by transferring only *
447  *  ONE parameter to PDFSET as before: this parameter should then      *
448  *  identify the NAME of the author group in an unequivocal way; the   *
449  *  selection of the PDF set within the author group is made by the    *
450  *  corresponding VALUE value (f.ex. PARM(1) = 'MRS' with VALUE(1) =   *
451  *  29.0D0 would select the 29th set of the Nucleon PDFs of MRS, and   *
452  *  f.ex. PARM(1) = 'GRVph' with VALUE(1) = 1.0D0 would select the     *
453  *  first set of the Photon PDFs of GRV). As a suggestion, the NAME for*
454  *  each PDF set can be found in the NEW COMMON block /W505110/SFNAME, *
455  *  where SFNAME is a CHARACTER*8 array with dimension SFNAME(NPTYMX,  *
456  *  NGRMAX,NSETMX), and NPTYMX, NGRMAX, NSETMX are defined by the      *
457  *  parameter sequence, +SEQ, W5051P2. In case the user wants to se-   *
458  *  lect the DEFAULT, it is sufficient to transfer as the ONLY parame- *
459  *  ter PARM(1) = 'Nset' with VALUE(1) = 0.0D0. This change of format  *
460  *  had been necessary to take into account the inflationary growing   *
461  *  number of PDFs until now and to foresee already the possibility of *
462  *  adding new PDFs in a more flexible way. Please note that in case   *
463  *  of any INCONSISTANCY of parameter settings, the DEFAULT setting is *
464  *  always chosen.                                                     *
465  *                                                                     *
466  *  WARNING : Please also note that the internal COMMON block /W50511/ *
467  *  has been modified to /W50511/ NPTYPE,NGROUP,NSET,MODE,NFL,LO,TMAS. *
468  *                                                                     *
469  *  A new feature, PDFLIB in quiet mode, has been implemented. If the  *
470  *  user does not want to see any output from PDFLIB, not even the     *
471  *  version number, he/she must set the parameter PARM(1)='first' with *
472  *  value VAL(1)=0.D0. Under this condition any output is suppressed.  *
473  *                                                                     *
474  *  Full backward compatibility with previous versions is ensured !!   *
475  *  This means that old programs using PDF sets up to version 3.00 of  *
476  *  PDFLIB should run without ANY change. To ensure this, four new     *
477  *  COMMON blocks have been added:                                     *
478  *                                                                     *
479  *    - /W50519/ NEWVER :  to flag the NEW/OLD version with the        *
480  *      LOGICAL variable NEWVER,                                       *
481  *                                                                     *
482  ******************************** - 6 - ********************************
483 1***********************************************************************
484  *                                                                     *
485  *    - /W505120/ NPGSMX(NPTYMX,NGRMAX),NSETFL(NPTYMX,NGRMAX,NSETMX) : *
486  *      to provide the actual maximum number of parametrisation sets   *
487  *      per particle type and author group, and to flag the retracted  *
488  *      PDF sets (NSETFL(I,J,K) = 0),                                  *
489  *    - /W505121/ NPTYCR(MODEMX),NGROMX(MODEMX),NSETCR(MODEMAX) :      *
490  *      to provide the cross reference to the NPTYPE, NGROUP and NSET  *
491  *      value (NEW format) for a given MODE value (OLD format),        *
492  *    and                                                              *
493  *    - /W505122/ MODECR(NPTYMX,NGRMAX,NSETMX) :  to provide the       *
494  *      cross reference to the MODE value (OLD version) for a given    *
495  *      NPTYPE, NGROUP and NSET value (NEW format). In case of the     *
496  *      above added PDF sets NO MODE value is available; in that case  *
497  *      MODECR(I,J,K) = -1 is returned.                                *
498  *                                                                     *
499  *                                                                     *
500  *                                                                     *
501  *                                                                     *
502  *  0.5  Version 3.00 wrt Version 2.00                                 *
503  *                                                                     *
504  *                                                                     *
505  *     The following major changes compared to version 2.00 of PDFLIB  *
506  *  had been implemented:                                              *
507  *                                                                     *
508  *  NUCLEON structure function sets had been updated or added:         *
509  *                                                                     *
510  *    - the NLL set of Aurenche et al. (ABFOW),                        *
511  *    - the updated NLL set of Kwiecinski, Martin, Roberts and         *
512  *      Stirling (KMRS) set B0 with u_bar not equal to d_bar           *
513  *      of April 1992,                                                 *
514  *    - the new NLL sets of Martin, Roberts and Stirling (MRS)         *
515  *      set S0, D0 and D- with u_bar not equal to d_bar of April 1992. *
516  *                                                                     *
517  *  Please note that the default set had been put to the MRS set S0    *
518  *  (MODE = 45).                                                       *
519  *                                                                     *
520  *  PION structure function sets had been added:                       *
521  *                                                                     *
522  *    - the new LO and NLL sets of Gl"uck, Reya and Vogt (GRV-P)       *
523  *      of August 1991,                                                *
524  *    - the new sets 2 and 3 of Aurenche et al. (ABFKW-P).             *
525  *                                                                     *
526  *  Please also note that the ABFKW set had changed MODE number from   *
527  *  110 -> 180, as well as the SMRS sets from 120ff -> 130ff, and      *
528  *  that earlier inconsistencies in the parton density definitions     *
529  *  had been corrected.                                                *
530  *                                                                     *
531  *  For the first time also PHOTON structure function sets had been    *
532  *  added to the package. These sets were the following:               *
533  *                                                                     *
534  *    - the old Duke and Owens (DO-G) LO and NLL sets,                 *
535  *    - the old LO sets 1 to 4 of Drees and Grassie (DG-G),            *
536  *    - the new LO sets 1 to 3 of Abramowicz, Charchula and Levy       *
537  *      (LAC-G),                                                       *
538  *    - the new LO sets 1 and 2 and the NLL set of Gordon and Storrow  *
539  *      (GS-G) of July 1991,                                           *
540  *    - the new LO and NLL sets, as well as the leading term of the    *
541  *      NLL calculation of Gl"uck, Reya and Vogt (GRV-G)               *
542  *      of December 1991,                                              *
543  *    - the new NLL sets of Aurenche et al. (ACFGP-G) of April 1992.   *
544  *                                                                     *
545  *  Some improvements in the usage of the package had been made:       *
546  *                                                                     *
547  *    - more protections had been implemented and inconsistencies      *
548  *      had been corrected to make the package more robust and         *
549  *      available on ALL system areas, and finally                     *
550  *                                                                     *
551  ******************************** - 7 - ********************************
552 1***********************************************************************
553  *                                                                     *
554  *    - the subroutine STRUCTM had been added. STRUCTM is basically    *
555  *      the same routine as the old steering subroutine STRUCTF apart  *
556  *      from ONE additional parameter in the argument list which had   *
557  *      been added to transfer separately the parton densities for     *
558  *      u_bar and d_bar. The argument list of the subroutine STRUCTF   *
559  *      was as before; in case of STRUCTF sea = (u_bar + d_bar)/2 is   *
560  *      transferred. The subroutine PFTOPDG, which is the sterring     *
561  *      routine in PDG format, was unchanged; this routine always      *
562  *      transferred u_bar and d_bar separately.                        *
563  *                                                                     *
564  *                                                                     *
565  *                                                                     *
566  *                                                                     *
567  *  0.6  Version 2.00 wrt Version 1.00                                 *
568  *                                                                     *
569  *                                                                     *
570  *     The following major changes compared to version 1.00 of PDFLIB  *
571  *  had been implemented:                                              *
572  *                                                                     *
573  *  New parton density functions of the NUCLEON had been added:        *
574  *                                                                     *
575  *    - the old LO set of Buras and Gaemers of 1978 (BEBC) for com-    *
576  *      pleteness,                                                     *
577  *    - all the LO sets of Diemoz, Ferroni, Longo and Martinelli (DFLM)*
578  *      including their parametrisation for the NLL average fit,       *
579  *    - the new LO set 1.1 of Owens (DO 1.1) of June 1991,             *
580  *    and finally                                                      *
581  *    - the new LO and NLL sets of Gl"uck, Reya and Vogt (GRV) of      *
582  *      May 1991.                                                      *
583  *                                                                     *
584  *  PION structure function sets had been added to the package:        *
585  *                                                                     *
586  *    - the old Owens (OW-P) sets 1 and 2,                             *
587  *    - the newer Aurenche et al. (ABFKW-P) set and                    *
588  *    - the new Sutton, Martin, Roberts and Stirling (SMRS-P) sets 1,  *
589  *      2 and 3.                                                       *
590  *                                                                     *
591  *  Some improvements in the usage of the package had been made:       *
592  *                                                                     *
593  *    - COMMON block names had been changed to avoid interference      *
594  *      to those defined by the user (/IMODE/ -> /W50511/,             *
595  *      /ALAMB/ -> /W50512/),                                          *
596  *    - three new COMMON blocks had been added:                        *
597  *      a) /W50513/ XMIN,XMAX,Q2MIN,Q2MAX :                            *
598  *         to provide the minimum and maximum values of X and Q**2 for *
599  *         each set of structure functions,                            *
600  *      b) /W50510/ IFLPRT :                                           *
601  *         to provide a print flag at different levels to print        *
602  *         b.1) the variables of the three COMMON blocks               *
603  *              /W50511/, /W50512/ and /W50513/ at job initialisation  *
604  *         b.2) error messages during job execution                    *
605  *      c) /W50514W/ PDFWGT :                                          *
606  *         to take into account the event weight for error counting    *
607  *    - a subroutine PDFSTA had been added to allow at job termination *
608  *      for a summary how often X and Q**2 limits have been exceeded,  *
609  *    - the MODE number of some structure functions had been changed   *
610  *      to keep consistensy,                                           *
611  *    - the number of parameters which can be set through the sub-     *
612  *      routine PDFSET had been extended to 20,                        *
613  *    - more protections had been implemented and inconsistencies      *
614  *      had been corrected to make the package more robust,            *
615  *    and finally                                                      *
616  *    - a subroutine PFTOPDG had been provided as an interface for     *
617  *      those users who prefer the flavour code convention of the PDG  *
618  *      instead of the PDFLIB format.                                  *
619  *                                                                     *
620  ******************************** - 8 - ********************************
621 1***********************************************************************
622  *                                                                     *
623  *  1. The Library of Parton Densities: PDFLIB                         *
624  *                                                                     *
625  *                                                                     *
626  *  1.1. Introduction                                                  *
627  *                                                                     *
628  *                                                                     *
629  *     Perturbative QCD describes the $Q^2$ dependence of the parton   *
630  *  densities through the solution of the Altarelli-Parisi equations.  *
631  *  Its predictive power is given by the universality of these densi-  *
632  *  ties. Usually these densities are extracted from precision mea-    *
633  *  surements in fixed-target experiments of a given process at some   *
634  *  scale - recently they have also been extracted from the HERA ep-   *
635  *  collision experiments -, and then used to perform calculations for *
636  *  different reactions in an extrapolated range of $Q^2$ provided     *
637  *  that the elementary cross sections at the parton level are known.  *
638  *  To be able to predict cross sections for a wide range of hard      *
639  *  scattering processes, it is of fundamental importance to have a    *
640  *  reliable and precise set of parton density distributions, together *
641  *  with a precise value of the strong coupling constant alpha_s.      * 
642  *  Therefore the momentum distributions of quarks and gluons are key  *
643  *  ingredients for the lepton-lepton, lepton-hadron and hadron-hadron *
644  *  collider phenomenology, whenever the hadronic structure of nucle-  *
645  *  ons, pions or photons is involved. Apart from the obvious applica- *
646  *  tions mentioned above, the study of parton distributions provides  *
647  *  also information about flavour dependence, isospin symmetry, par-  *
648  *  tons in nuclei, sum rules, polarized parton distibutions, etc..    *
649  *  For any application the parton densities should therefore be       *
650  *  sufficiently well known, and the different sets should be easily   *
651  *  accessible.                                                        *
652  *                                                                     *
653  *                                                                     *
654  *                                                                     *
655  *                                                                     *
656  *  1.2. Structure Functions of the Nucleon                            *
657  *                                                                     *
658  *                                                                     *
659  *     The number of sets of parton density functions of the NUCLEON   *
660  *  available today is about 70 and is still growing. The older sets   *
661  *  are leading order (LO) evolutions of the Altarelli-Parisi equa-    *
662  *  tions only, like                                                   *
663  *                                                                     *
664  *    - Buras and Gaemers (BEBC) [1],                                  *
665  *    - Owens and Reya (OR) [2],                                       *
666  *    - Baier, Engels and Petersson (BEP) [3],                         *
667  *    - Gl"uck, Hoffmann and Reya (GHR) [4],                           *
668  *    - Duke and Owens (DO) sets 1 and 2 [5],                          *
669  *    - Eichten, Hinchliffe, Lane and Quigg (EHLQ) sets 1 and 2 [6],   *
670  *    - Diemoz, Ferroni, Longo and Martinelli (DFLM) [7] with          *
671  *      Lambda_4(QCD) = 200 MeV for soft and hard valence quark and    *
672  *      soft and hard gluon distributions],                            *
673  *                                                                     *
674  *    and                                                              *
675  *                                                                     *
676  *    - the set 1.1 of Owens (DO 1.1) [8], replacing the DO [5] sets 1 *
677  *      and 2.                                                         *
678  *                                                                     *
679  *     Most of the sets, essentially the more recent ones, are         *
680  *  next-to-leading order evolutions, like                             *
681  *                                                                     *
682  *    - Diemoz, Ferroni, Longo and Martinelli (DFLM) with              *
683  *      Lambda_4(QCD) = 160, 260, 360 MeV [7],                         *
684  *    - Martin, Roberts and Stirling (MRS) sets 1 to 3, sets E and B   *
685  *      and sets E' and B' [9],                                        *
686  *    - Harriman, Martin, Roberts and Stirling (HMRS) sets E, E+, E-   *
687  *      and B [10],                                                    *
688  *                                                                     *
689  ******************************** - 9 - ********************************
690 1***********************************************************************
691  *                                                                     *
692  *    - Kwiecinski, Martin, Roberts and Stirling (KMRS) [11] sets B0   *
693  *      and B-, and for the B- set with different radii for shadowing, *
694  *    - Martin, Roberts and Stirling (MRS-B Lambda) [11] for the B0    *
695  *      set also with different values of Lambda_4(QCD) = 135, 160,    *
696  *      200 and 235 MeV,                                               *
697  *    - Martin, Roberts and Stirling (MRS) [12] sets S0, D0 and D-     *
698  *      as well as the upgraded KMRS set B0, all having u_bar not      *
699  *      equal to d_bar,                                                *
700  *    - Morfin and Tung (MT) sets 1 to 6 [13],                         *
701  *    - Gl"uck, Reya and Vogt (GRV) [14] including their new para-     *
702  *      metrisation from August 1991,                                  *
703  *    - the set of Aurenche et al. (ABFOW) [15],                       *
704  *    - the upgraded Martin, Roberts and Stirling (MRS) [16] sets      *
705  *      S0', D0' and D-' as well as the more recent MRS(H) set, all in *
706  *      both, the MS_bar and the DIS renormalisation schemes,          *
707  *    - the upgraded Martin, Roberts and Stirling (MRS) [17] sets      *
708  *      S0', D0' and D-' in the DIS renormalisation scheme and MRS(H), *
709  *    - the Berger and Meng (BM) [17] sets 1 and 2 with special gluon  *
710  *      distributions,                                                 *
711  *    - the two first versions of the CTEQ collaboration (CTEQ1 and    *
712  *      CTEQ2) [18],                                                   *
713  *    - the set of Martin, Roberts and Stirling (MRS-A) [19] in form   *
714  *      of a grid and in form of a parametrisation,                    *
715  *    - the two sets of Martin, Roberts and Stirling (MRS-A' and       *
716  *      MRS-G) [20] in form of a grid and in form of a parametrisation,*
717  *    - the third versions of the CTEQ collaboration (CTEQ3) [21],     *
718  *    - the 1994 set of Gl\"{u}ck, Reya and Vogt (GRV) [22],           *
719  *    - the recent sets of Martin, Roberts and Stirling for low Q^2    *
720  *      (MRS-A lQ) [23] and the MRS-A' sets for 6 different values of  *
721  *      alpha_s (MRS-Ap-150 to MRS-Ap-542) [24],                       *
722  *    - the more recent sets of Martin, Roberts and Stirling (MRS-J    *
723  *      and MRS-Jp) [25] and the latest sets R1 to R4 (MRS-R1 to       *
724  *      MRS-R4) [26] in form of a grid and in form of a parametrisa-   *
725  *      tion,                                                          *
726  *    - the fourth versions of the CTEQ collaboration (CTEQ4) [27],    *
727  *                                                                     *
728  *    and finally                                                      *
729  *                                                                     *
730  *    - the LO and NLL sets of Gl\"{u}ck, Reya, Stratmann and          *
731  *      Vogelsang (GRSV) [28] of polarized parton densities,           *
732  *                                                                     *
733  *     The different NLL sets use either the DIS [44] or the MS_bar    *
734  *  renormalisation scheme. Some of the sets are available in both     *
735  *  renormalisation schemes. All sets are made using four flavours in  *
736  *  the initial state (NF = 4). The value of the QCD scale factor,     *
737  *  Lambda_4(QCD), ranges from 45 to 500 MeV.                          *
738  *                                                                     *
739  *     A summary of all parton density functions of the NUCLEON avai-  *
740  *  lable in the package can be found in Table 1.                      *
741  *                                                                     *
742  *                                                                     *
743  *                                                                     *
744  *                                                                     *
745  *                                                                     *
746  *                                                                     *
747  *                                                                     *
748  *                                                                     *
749  *                                                                     *
750  *                                                                     *
751  *                                                                     *
752  *                                                                     *
753  *                                                                     *
754  *                                                                     *
755  *                                                                     *
756  *                                                                     *
757  *                                                                     *
758  ******************************* - 10 - ********************************
759 1***********************************************************************
760  *                                                                     *
761  *  1.3. Structure Functions of the Pion                               *
762  *                                                                     *
763  *                                                                     *
764  *     There is also a limited number of parton density functions of   *
765  *  the PION available. These are the old set to leading order evolu-  *
766  *  tion of                                                            *
767  *                                                                     *
768  *    - Owens (OW-P) [29], sets 1 and 2,                               *
769  *                                                                     *
770  *    and the next-to-leading order evolutions of                      *
771  *                                                                     *
772  *    - Aurenche et al. (ABFKW-P) [30], sets 1, 2 and 3,               *
773  *    - Sutton, Martin, Roberts and Stirling (SMRS-P) [31], sets 1, 2  *
774  *      and 3 and                                                      *
775  *    - Gl"uck, Reya and Vogt (GRV-P) [32], the LO and NLL sets.       *
776  *                                                                     *
777  *     A summary of all parton density functions of the PION availble  *
778  *  in the package can be found in Table 2.                            *
779  *                                                                     *
780  *                                                                     *
781  *                                                                     *
782  *                                                                     *
783  *  1.4. Structure Functions of the Photon                             *
784  *                                                                     *
785  *                                                                     *
786  *     In addition there are also a few parton density functions of    *
787  *  the PHOTON available. These are the old sets to leading order evo- *
788  *  lution of                                                          *
789  *                                                                     *
790  *    - Duke and Owens (DO-G) (and the NLL) [33] using an asymptotic   *
791  *      solution of the Altarelli-Parisi equation,                     *
792  *    - Drees and Grassie (DG-G) sets 1 to 4 [34] using a full solu-   *
793  *      tion of the Altarelli-Parisi equation,                         *
794  *    - Abramowicz, Charchula and Levy (LAC-G) [35] sets 1 to 3 using  *
795  *      a full solution of the Altarelli-Parisi equation,              *
796  *                                                                     *
797  *    and of                                                           *
798  *                                                                     *
799  *    - Watanabe, Hagiwara, Izubuchi and Tanaka (WHIT1 to WHIT6) [36], *
800  *                                                                     *
801  *    and the next-to-leading order evolution of                       *
802  *                                                                     *
803  *    - Gordon and Storrow (GS-G) [37], the LO sets 1 and 2 and the    *
804  *      NLL set,                                                       *
805  *    - Gl"uck, Reya and Vogt (GRV-G) [38], the LO, NLL and the        *
806  *      leading term of the NLL sets,                                  *
807  *    - Aurenche et al. (ACFGP-G) [39] sets 1 and 2, without and with  *
808  *      massive charm,                                                 *
809  *                                                                     *
810  *    and finally                                                      *
811  *                                                                     *
812  *    _ the LO and NLL sets of Aurenche, Fontannaz and Guillet,        *
813  *      (AFG-G) [40].                                                  *
814  *                                                                     *
815  *     Recently new sets of of the parton densities of the photon have *
816  *  been come out:                                                     *
817  *                                                                     *
818  *    - Schuler and Sjostrand (SaS-G) [41],                            *
819  *    - the new sets of Gl"uck, Reya and Stratmann (GRG-G) [42],       *
820  *    and                                                              *
821  *    - the new sets LO and NLL of Gordon and Storrow (GS-G) [43].     *
822  *                                                                     *
823  *     A summary of all parton density functions of the PHOTON avai-   *
824  *  lable in the package can be found in Table 3.                      *
825  *                                                                     *
826  *                                                                     *
827  ******************************* - 11 - ********************************
828 1***********************************************************************
829  *                                                                     *
830  *  1.5 The Library PDFLIB                                             *
831  *                                                                     *
832  *                                                                     *
833  *     We have put together all these different sets of parton density *
834  *  functions in ONE SINGLE PACKAGE [45]. This library PDFLIB can be   *
835  *  found in and obtained from the CERN Computer Program Library under *
836  *  the registration number W5051.                                     *
837  *                                                                     *
838  *     Please notice that the use of the PDFLIB library does not pre-  *
839  *  vent to consult the publications of the different authers, which   *
840  *  can be found in the bibliography of this manual, for details about *
841  *  each parton density function.                                      *
842  *                                                                     *
843  *     We have modified the sets such that NO external data files for  *
844  *  the grids have to be read in anymore. All these structure function *
845  *  sets have been combined in a consistent way such that they all     *
846  *  appear in an IDENTICAL STRUCTURE to the user. The selection is     *
847  *  made via THREE parameters, NPTYPE, NGROUP and NSET, which identify *
848  *  a PDF set by its PARTICLE TYPE (Nucleon: NPTYPE = 1,               *
849  *  Pion: NPTYPE = 2, Photon: NPTYPE = 3), its AUTHOR GROUP (f.ex.     *
850  *  MRS: NGROUP = 3, CTEQ: NGROUP = 4, GRV: NGROUP = 5) and its PDF    *
851  *  SET WITHIN THE GROUP (NSET = 1,2,3 etc.). These parameters should  *
852  *  be set with a call to subroutine PDFSET at the initialization      *
853  *  phase. A simple SUBROUTINE call, which is IDENTICAL for all appli- *
854  *  cations (nucleons, pions, photons) returns the parton densities    *
855  *  for all partons (u, d, s, c, b, t, gluon and their antiquarks) at  *
856  *  a given X value (where X is the fraction of the longitudinal       *
857  *  momentum carried by the parton) and the Q-scale SCALE (in GeV).    *
858  *  A DEFAULT set has been prepared, although those preferring their   *
859  *  OWN PRIVATE set or wanting to test a NEW one may do so within the  *
860  *  package. Error control can be obtained by setting a print flag to  *
861  *  obtain output either during execution and/or as a summary at job   *
862  *  termination via a call to the subroutine PDFSTA.                   *
863  *                                                                     *
864  *     The source code of the different parton density sets has been   *
865  *  modified in such a way that the library can be used on all the     *
866  *  different computer systems known today. Full backward compatibi-   *
867  *  lity will always be assured. PDFLIB has been run under different   *
868  *  operating systems like VM/CMS, VAX/VMS and ULTRIX without pro-     *
869  *  blems. The library has been tested on the different system areas   *
870  *  to ensure identical results within the given machine precision.    *
871  *  The program has been run and tested on the following computers:    *
872  *  IBM 3090, VAX, IBM-RISC, DECS, SUN, APOLLO, HP-UX, Silicon         *
873  *  Graphics, CDC, CRAY, IBM-PC. The programming language is           *
874  *  FORTRAN 77. The actual source code manager system used is CVS.     *
875  *  The required memory storage including testprograms and some docu-  *
876  *  mentation is about 25 Mbytes. The latest edition (July 1997)       *
877  *  is version 7.09 and can be requested from the CERN Computer        *
878  *  Program Library. To run PDFLIB a link to the CERN library          * 
879  *  (PACKLIB, MATHLIB and KERNLIB) is required.                        * 
880  *                                                                     *
881  *                                                                     *
882  *                                                                     *
883  *  1.6. Calculation of the Stroing Coupling constant alpha(s)         *
884  *                                                                     *
885  *                                                                     *
886  *     Within the SAME package a program is also provided to calculate *
887  *  the strong coupling constant alpha(s) to second order (default)    *
888  *  or to first order (by user's choice). The correct Lambda(QCD) as-  *
889  *  sociated to the selected set of structure functions and the number *
890  *  of allowed flavours with respect to the given Q**2 is automati-    *
891  *  cally used in the calculation. For those structure functions where *
892  *  the evolution has been performed to leading order only, the        *
893  *  alpha(s) value to first order is returned.                         *
894  *                                                                     *
895  *                                                                     *
896  ******************************* - 12 - ********************************
897 1***********************************************************************
898  *                                                                     *
899  *  2.  Application of the Parton Density Package PDFLIB               *
900  *                                                                     *
901  *                                                                     *
902  *     In the following the use of and the access to the PDFLIB pack-  *
903  *  age is described.                                                  *
904  *                                                                     *
905  *                                                                     *
906  *                                                                     *
907  *  2.1  Parameter Setting and Selection of Sets                       *
908  *                                                                     *
909  *                                                                     *
910  *     To access his/her preferred set of structure functions the user * 
911  *  must define the THREE parameters, NPTYPE, NGROUP and NSET, which   *
912  *  identify each set of parton density functions via a call to the    *
913  *  subroutine                                                         *
914  *                                                                     *
915  *       CALL PDFSET(PARM,VALUE)                                       *
916  *                                                                     *
917  *  at the initialization phase of his/her MAIN program, or use the    *
918  *  package as a 'black box' with the default values (see below). An   *
919  *  example of the application of PDFLIB is given in the appendix. The *
920  *  arguments PARM and VALUE are VECTORS of DIMENSION 20 and have the  *
921  *  following meaning                                                  *
922  *                                                                     *
923  *       PARM(I)  = character*20 variable, which defines in any order  *
924  *                  the variables                                      *
925  *                  'NPTYPE', 'NGROUP', 'NSET', 'MODE', 'INIT0',       *
926  *                  'NFL', 'LO', 'TMAS', 'QCDL4', 'QCDL5' and          *
927  *                  'XMIN', 'XMAX', 'Q2MIN', 'Q2MAX'                   *
928  *       VALUE(I) = the corresponding numerical value of the variable  *
929  *                  PARM(I)                                            *
930  *                  (TMAS, QCDL4, QCDL5, XMIN, XMAX, Q2MIN and Q2MAX   *
931  *                  are DOUBLE PRECISION variables),                   *
932  *                                                                     *
933  *  where                                                              *
934  *                                                                     *
935  *       NPTYPE = number of particle type ranging from 1 to 3          *
936  *                (Nucleons: NPTYPE = 1, Pions: NPTYPE = 2 and         *
937  *                 Photons: NPTYPE = 3)                                *
938 *                  (Default: NPTYPE = 1)                               *
939  *       NGROUP = number of author group ranging from 1 to 9           *
940  *                (Default: NGROUP = 3)                                *
941  *       NSET   = number of a selected structure function set within   *
942  *                the author group ranging from 1 to 58                *
943  *                (Default: NSET = 41)                                 *
944  *      (MODE   = number of a selected structure function set ranging  *
945  *                from 0 to 281 - OLD format !!)                       *
946  *                (Default: MODE = 45)                                 *
947  *       INIT0  = in case of PARM(1) = 'INIT0' PDFSET fills as the     *
948  *                only action the COMMON blocks /W505110/, /W505120/   *
949  *                /W505121/ and /W505122/                              *
950  *       NFL    = desired number of flavours in the alpha(s) calcula-  *
951  *                tion ranging from 3 to 6                             *
952  *                (Default: NFL = 5)                                   *
953  *       LO     = order of alpha(s) calculation; if LO = 1, alpha(s)   *
954  *                to first order only                                  *
955  *                (Default: LO = 2)                                    *
956  *       TMAS   = the user defined value of the top-quark mass in      *
957  *                GeV/c**2 (optional)                                  *
958  *                (Default: TMAS = 180.0D0)                            *
959  *       QCDL4  = QCD scale, Lambda_4(QCD), in GeV for four flavours   *
960  *       QCDL5  = QCD scale, Lambda_5(QCD), in GeV for five flavours   *
961  *                corresponding to QCDL4                               *
962  *                                                                     *
963  *  and                                                                *
964  *                                                                     *
965  ******************************* - 13 - ********************************
966 1***********************************************************************
967  *                                                                     *
968  *       XMIN   = minimum allowed X value                              *
969  *       XMAX   = maximum allowed X value                              *
970  *       Q2MIN  = minimum allowed Q**2 value (in (GeV/c)**2)           *
971  *       Q2MAX  = maximum allowed Q**2 value (in (GeV/c)**2)           *
972  *                                                                     *
973  *  for each set of structure functions.                               *
974  *                                                                     *
975  *     Please also note that PDFSET can be called as often as the user *
976  *  likes. In order to redefine the parameters to select other sets of *
977  *  structure functions which the user wants to investigate, it might  *
978  *  be necessary to call PDFSET in an alternating way, but it is al-   *
979  *  ways mandatory to transfer either the THREE parameters, NPTYPE,    *
980  *  NGROUP, NSET, or the 'NAME' of the author group with their corres- *
981  *  ponding VALUE values. The subroutine PDFSET fills the internal     *
982  *  COMMON blocks                                                      *
983  *                                                                     *
984  *       COMMON/W50511/ NPTYPE,NGROUP,NSET,MODE,NFL,LO,TMAS            *
985  *       COMMON/W50512/ QCDL4,QCDL5                                    *
986  *       COMMON/W50513/ XMIN,XMAX,Q2MIN,Q2MAX                          *
987  *                                                                     *
988  *  at the time the routine is called. Please note that in case of a   *
989  *  multiple call to PDFSET with fewer parameters redefined than in a  *
990  *  preceeding call, always the last parameters are kept in memory.    *
991  *  All variables of the three COMMON blocks can be automatically      *
992  *  printed at job initialisation by setting the print flag IFLPRT in  *
993  *  the COMMON block                                                   *
994  *                                                                     *
995  *       COMMON/W50510/ IFLPRT                                         *
996  *                                                                     *
997  *  to IFLPRT = 2.                                                     *
998  *                                                                     *
999  *     The program is protected against calculations of Q^2 values     *
1000  *  below Q2MIN (in this case Q^2 = Q2MIN) and of X values in unphysi- *
1001  *  cal regions (X < 0 or X > 1). The execution of the program is      *
1002  *  stopped in the later case. To control how often the X or Q^2 ran-  *
1003  *  ges have been exceeded during execution of the user's program a    *
1004  *  call to the subroutine                                             *
1005  *                                                                     *
1006  *       CALL PDFSTA                                                   *
1007  *                                                                     *
1008  *  at the termination phase of his/her MAIN program allows to print a *
1009  *  summary of these errors. The print flag in the COMMON/W50510/IFLPRT* 
1010  *  may be set to IFLPRT = 3 to print an error message EACH TIME a     *
1011  *  limit has been exceeded during job execution. Please note that     *
1012  *  this may produce an ENORMOUS AMOUNT OF OUTPUT !                    *
1013  *                                                                     *
1014  *                                                                     *
1015  *                                                                     *
1016  *                                                                     *
1017  *                                                                     *
1018  *  2.2  The Calling Sequence: PDFLIB Format                           *
1019  *                                                                     *
1020  *                                                                     *
1021  *     The main steering routine for a set of structure functions is   *
1022  *  accessed as follows:                                               *
1023  *                                                                     *
1024  *       CALL STRUCTM(X,SCALE,UPV,DNV,USEA,DSEA,STR,CHM,BOT,TOP,GL)    *
1025  *                                                                     *
1026  *     Please note that all variables are defined as DOUBLE PRECISION. *
1027  *  The user has to provide the following INPUTs:                      *
1028  *                                                                     *
1029  *       X      = X value of parton                                    *
1030  *       SCALE  = QCD scale in GeV                                     *
1031  *                                                                     *
1032  *     The subroutine STRUCTM returns the following OUTPUT:            *
1033  *                                                                     *
1034  ******************************* - 14 - ********************************
1035 1***********************************************************************
1036  *                                                                     *
1037  *       UPV    = up valence quark                                     *
1038  *       DNV    = down valence quark                                   *
1039  *       USEA   = sea (up_bar)                                         *
1040  *       DSEA   = sea (down_bar)                                       *
1041  *       STR    = strange quark                                        *
1042  *       CHM    = charm quark                                          *
1043  *       BOT    = bottom quark                                         *
1044  *       TOP    = top quark                                            *
1045  *       GL     = gluon                                                *
1046  *                                                                     *
1047  *     In case up_bar is not given separately from down_bar it is set  *
1048  *  USEA = DSEA.                                                       *
1049  *                                                                     *
1050  *     The recommended set of structure functions from the different   *
1051  *  authors is put in bold characters. If NSET is set to zero (or if   *
1052  *  any of the parameters, NPTYPE, NGROUP or NSET, is undefined) ONE   *
1053  *  DEFAULT SET is selected which is always the Nucleon parton densi-  *
1054  *  ties, the set of MRS set G (NPTYPE = 1, NGROUP = 3, NSET = 41),    *
1055  *  also in case of NPTYPE = Pion or Photon.                           *
1056  *                                                                     *
1057  *     Please note that in any of the calling sequences for the        *
1058  *  nucleon, the pion and the photon it is always returned             *
1059  *  X * parton distribution function !                                 *
1060  *                                                                     *
1061  *                                                                     *
1062  *                                                                     *
1063  *                                                                     *
1064  *  2.3  The Calling Sequence: PDG Format                              *
1065  *                                                                     *
1066  *                                                                     *
1067  *     To allow the use of the package with the flavour code conven-   *
1068  *  tion of the Particle Data Group (PDG) an interface has been writ-  *
1069  *  ten which translates the PDFLIB format (see Section 2.2) into the  *
1070  *  PDG format. Instead of calling the subroutine STRUCTM the user     *
1071  *  preferring the flavour code convention of the PDG accesses the     *
1072  *  package via a call to the subroutine                               *
1073  *                                                                     *
1074  *       CALL PFTOPDG(X,SCALE,DXPDF).                                  *
1075  *                                                                     *
1076  *     All variables are defined as DOUBLE PRECISION as before, and    *
1077  *  X and SCALE are INPUTs provided by the user having the same        *
1078  *  meaning as before.                                                 *
1079  *                                                                     *
1080  *     The subroutine PFTOPDG outputs a vector DXPDF(-6:6) of which    *
1081  *  its variables have the following meaning:                          *
1082  *                                                                     *
1083  *       DXPDF(0)  = gluon                                             *
1084  *       DXPDF(1)  = sum of down valence + down_bar quark              *
1085  *       DXPDF(2)  = sum of up valence + up_bar quark                  *
1086  *       DXPDF(3)  = strange quark                                     *
1087  *       DXPDF(4)  = charm quark                                       *
1088  *       DXPDF(5)  = bottom quark                                      *
1089  *       DXPDF(6)  = top quark                                         *
1090  *  and  DXPDF(-1) to DXPDF(-6) are the corresponding antiquarks.      *
1091  *                                                                     *
1092  *     DXPDF(-1) = DXPDF(-2) stands for down_bar = up_bar or           *
1093  *  (down_bar + up_bar)/2 in almost all parametrisations. In case      *
1094  *  where u_bar is not equal to d_bar DXPDF(-1) = d_bar and            *
1095  *  DXPDF(-2) = u_bar. In all sets is DXPDF(3) = DXPDF(-3),            *
1096  *  DXPDF(4) = DXPDF(-4), DXPDF(5) = DXPDF(-5) and                     *
1097  *  DXPDF(6) = DXPDF(-6) so far.                                       *
1098  *                                                                     *
1099  *                                                                     *
1100  *                                                                     *
1101  *                                                                     *
1102  *                                                                     *
1103  ******************************* - 15 - ********************************
1104 1***********************************************************************
1105  *                                                                     *
1106  *  2.4  Error Handling                                                *
1107  *                                                                     *
1108  *                                                                     *
1109  *     A note of caution should be addressed here. All structure       *
1110  *  functions are limited in X and Q**2 which range for most of the    *
1111  *  sets from                                                          *
1112  *                                                                     *
1113  *       4 - 10            < Q**2 < 10**6 - 10**8 (GeV/c)**2           *
1114  *       10**{-5} - 10**{-4} < X < 1.                                  *
1115  *                                                                     *
1116  *     If the user wants to extend the X or Q**2 ranges, it is pos-    *
1117  *  sible for some of the structure function sets, but the result      *
1118  *  should be looked at with great caution. If in doubt, please check  *
1119  *  with the authors of the structure function set. The program is     *
1120  *  protected against calculations of Q**2 values below Q2MIN (in this *
1121  *  case Q**2 = Q2MIN) and of X values in unphysical regions (X < 0 or *
1122  *  X > 1). The execution of the program is stopped in the later case. *
1123  *                                                                     *
1124  *     A COMMON block can be accessed                                  *
1125  *                                                                     *
1126  *       COMMON/W50513/ XMIN,XMAX,Q2MIN,Q2MAX                          *
1127  *                                                                     *
1128  *  where                                                              *
1129  *                                                                     *
1130  *       XMIN   = minimum allowed X value                              *
1131  *       XMAX   = maximum allowed X value                              *
1132  *       Q2MIN  = minimum allowed Q**2 value (in (GeV/c)**2)           *
1133  *       Q2MAX  = maximum allowed Q**2 value (in (GeV/c)**2)           *
1134  *                                                                     *
1135  *  is given for each set of structure functions. To control how often *
1136  *  the X or Q**2 ranges have been exceeded during execution of the    *
1137  *  user's program a call to the subroutine                            *
1138  *                                                                     *
1139  *       CALL PDFSTA                                                   *
1140  *                                                                     *
1141  *  at the termination phase of his/her MAIN program allows to print   *
1142  *  a summary of these errors. If the COMMON block                     *
1143  *                                                                     *
1144  *       COMMON/W50514W/ PDFWGT                                        *
1145  *                                                                     *
1146  *  where                                                              *
1147  *                                                                     *
1148  *       PDFWGT = weight                                               *
1149  *                                                                     *
1150  *  is filled by the user on an event-to-event basis the statistics    *
1151  *  in the error summary takes into account this weight.               *
1152  *                                                                     *
1153  *     The print flag in the COMMON/W50510/IFLPRT may be set to        *
1154  *  IFLPRT = 3 to print an error message EACH TIME a limit is exeeded  *
1155  *  during job execution. Please note that setting this flag may pro-  *
1156  *  duce an ENORMOUS AMOUNT of output!                                 *
1157  *                                                                     *
1158  *                                                                     *
1159  *                                                                     *
1160  *                                                                     *
1161  *  2.5  Features                                                      *
1162  *                                                                     *
1163  *                                                                     *
1164  *     If NPTYPE = 1, NGROUP = 1 and NSET = 1, the user has the possi- *
1165  *  bility to use his/her own private set of structure functions       *
1166  *  (i.e. CDHS effective structure functions could be inseted here,    *
1167  *  or the user could implement a new set of structure functions for   *
1168  *  testing purposes). To insert the private set the DUMMY subroutine  *
1169  *                                                                     *
1170  *    SUBROUTINE STRPRIV(X,SCALE,UPV,DNV,USEA,DSEA,STR,CHM,BOT,TOP,GL) *
1171  *                                                                     *
1172  ******************************* - 16 - ********************************
1173 1***********************************************************************
1174  *                                                                     *
1175  *  should be activated by the user. All variables have to be defined  *
1176  *  as DOUBLE PRECISION. The variables have the same meaning as des-   *
1177  *  cribed for the subroutine STRUCTM in Section 2.2 (for explanations *
1178  *  see there).                                                        *
1179  *                                                                     *
1180  *     For the calculation of the strong coupling constant alpha(s)    *
1181  *  (see Section 3) with the user's private set of structure functions *
1182  *  the user should provide a value for the variables QCDL4 and QCDL5  *
1183  *  via the subroutine PDFSET at the initialization phase. In fact,    *
1184  *  because only the parameter QCDL5 is used in the alpha(s) calcul-   *
1185  *  ation, only this definition is mandatory.                          *
1186  *                                                                     *
1187  *                                                                     *
1188  *                                                                     *
1189  *                                                                     *
1190  *  2.6. How to find PDFLIB                                            *
1191  *                                                                     *
1192  *                                                                     *
1193  *     At CERN the PDFLIB library and corresponding documentation are  *
1194  *  available on all systems in the standard areas.                    *
1195  *                                                                     *
1196  *       System            Library                                     *
1197  *                                                                     *
1198  *       VXCERN            CERN:[NEW.LIB]PDFLIB.OLB                    *
1199  *       Unix systems      /cern/new/lib/libpdflib.a                   *
1200  *                                                                     *
1201  *                                                                     *
1202  *     At CERN on Unix systems the package may be accessed via the     *
1203  *  'cernlib' command:                                                 *
1204  *                                                                     *
1205  *    \ 'cernlib pdflib packlib mathlib kernlib' \                     *
1206  *                                                                     *
1207  *     All necessary information about PDFLIB can also be found on the *
1208  *  World Wide Web via the path 'CERN.Computing.CERNLIB.documentation' *
1209  *  or directly as                                                     *
1210  *                                                                     *
1211  *   for the flat version :                                            *
1212  *                http://wwwcn.cern.ch/asdoc/pdflib/pdflib.html        *
1213  *   or for the PostScript version :                                   *
1214  *                http://wwwcn.cern.ch/asdoc/psdir/pdflib.ps.gz        *
1215  *                                                                     *
1216  *     The source code of PDFLIB may be obtained from asisftp.cern.ch  *
1217  *  via anonymous ftp with:                                            *
1218  *                                                                     *
1219  *    get   /cernlib/share/new/src/mclibs/pdf         or               *
1220  *    get   /cernlib/share/new/src/mclibs/pdf.tar     or               *
1221  *    get   /cernlib/share/new/src/mclibs/pdf.tar.gz                   *
1222  *                                                                     *
1223  *  even, if the last two files are not visible via the command 'ls'.  *
1224  *                                                                     *
1225  *                                                                     *
1226  *     Whenever you use this program, please give reference to the     *
1227  *  following papers:                                                  *
1228  *                                                                     *
1229  *     H. Plothow-Besch, 'The Parton Distribution Function Library',   *
1230  *     Int. J. Mod. Phys. A10 (1995) 2901-2920.                        *
1231  *                                                                     *
1232  *  and/or                                                             *
1233  *                                                                     *
1234  *     H. Plothow-Besch, 'PDFLIB: A Library of all available Parton    *
1235  *     Density Functions of the Nucleon, the Pion and the Photon and   *
1236  *     the corresponding alpha_s Calculations',                        *
1237  *     Comp. Phys. Comm. 75 (1993) 396-416.                            *
1238  *                                                                     *
1239  *  and/or                                                             *
1240  *                                                                     *
1241  ******************************* - 17 - ********************************
1242 1***********************************************************************
1243  *                                                                     *
1244  *     H. Plothow-Besch, 'PDFLIB: Structure Functions and alpha_s      *
1245  *     Calculations',                                                  *
1246  *     User's Manual - Version 1.00, W5051 PDFLIB,                     *
1247  *     1991.03.21, CERN-PPE.                                           *
1248  *                                                                     *
1249  *  and/or                                                             *
1250  *                                                                     *
1251  *     H. Plothow-Besch, 'PDFLIB: Nucleon, Pion and Photon Parton      *
1252  *     Density Functions and alpha_s Calculations',                    *
1253  *     Users's Manual - Version 7.09, W5051 PDFLIB,                    *
1254  *     1997.07.02, CERN-PPE.                                           *
1255  *                                                                     *
1256  *                                                                     *
1257  *                                                                     *
1258  *                                                                     *
1259  *  3.  PION and PHOTON Parton Densities                               *
1260  *                                                                     *
1261  *                                                                     *
1262  *     The calling sequences to the PION and the PHOTON sets of parton *
1263  *  densities is kept identical to those described in Sections 2.2 and *
1264  *  2.3 for the nucleon structure functions.                           *
1265  *                                                                     *
1266  *     In case of the PION structure functions it is set and returned  *
1267  *  UPV = DNV, SEA = STR (USEA = DSEA = STR) and TOP = 0               *
1268  *  (DXPDF(1) = DXPDF(2), DXPDF(3) = DXPDF(-1) = DXPDF(-2) and         *
1269  *  DXPDF(6) = 0).                                                     *
1270  *                                                                     *
1271  *     In case of the PHOTON structure functions it is set and         *
1272  *  returned UPV = USEA, DNV = DSEA and TOP = 0                        *
1273  *  (DXPDF(1) = 2 * DXPDF(-1), DXPDF(2) = 2 * DXPDF(-2), as a result   *
1274  *  of the definitions - see Section 2.3 -, and DXPDF(6) = 0), while   *
1275  *  all the other quarks are set identical to their antiquark densi-   * 
1276  *  ties. Note that the alpha_(QED) has to be taken care of by the     *
1277  *  user !                                                             *
1278  *                                                                     *
1279  *     To take into account the need for more input parameters for     *
1280  *  parton densities of the photon a NEW SUBROUTINE STRUCTP has been   *
1281  *  added which should be called instead of STRUCTM in case of appli-  *
1282  *  cations of the photon. Therefore, the main steering routine for a  *
1283  *  set of structure functions of the photon should now be accessed    *
1284  *  as follows:                                                        *
1285  *                                                                     *
1286  *    CALL STRUCTP(X,Q2,P2,IP2,UPV,DNV,USEA,DSEA,STR,CHM,BOT,TOP,GL)   *
1287  *                                                                     *
1288  *  Please note that all variables (INPUT and OUTPUT) are defined as   *
1289  *  DOUBLE PRECISION. The user has now to provide the following        *
1290  *  INPUTs:                                                            *
1291  *                                                                     *
1292  *     X    =  x value of parton                                       *
1293  *     Q2   =  QCD scale in GeV**2                                     *
1294  *     P2   =  virtuality of the photon in GeV**2,                     * 
1295  *             should be = 0 for an on-shell photon                    *
1296  *     IP2  =  parameter to evaluate off-shell anomalous component     *
1297  *                                                                     *
1298  *     The OUTPUT parameters are defined as for STRUCTM (see           *
1299  *  Section 2.2).                                                      *
1300  *                                                                     *
1301  *                                                                     *
1302  *                                                                     *
1303  *                                                                     *
1304  *                                                                     *
1305  *                                                                     *
1306  *                                                                     *
1307  *                                                                     *
1308  *                                                                     *
1309  *                                                                     *
1310  ******************************* - 18 - ********************************
1311 1***********************************************************************
1312  *                                                                     *
1313  *  4.  alpha(s) Calculation                                           *
1314  *                                                                     *
1315  *                                                                     *
1316  *     Within the same package a program is provided to calculate the  *
1317  *  strong coupling constant alpha(s) to second order as a function    *
1318  *  of Lambda(QCD) of five flavours and the desired number of fla-     *
1319  *  vours (NFL) for the selected set of structure functions, which     *
1320  *  fixes Lambda(QCD). The formula on which the calculations are       *
1321  *  based upon can be found in Ref. [46]. The same three parameters,   *
1322  *  NPTYPE, NGROUP and NSET, which select a structure function set,    *
1323  *  is used to steer the calculation of the alpha(s) value at a given  *
1324  *  scale from the Lambda(QCD) defined in the selected structure       *
1325  *  function.                                                          *
1326  *                                                                     *
1327  *      The value of alpha(s) is matched at the thresholds q = m_q.    *
1328  *  When invoked with NFL < 0, it chooses NFL as the number of fla-    *
1329  *  vours for which the masses are less then q. For the quark masses   *
1330  *  where thresholds are changed the following values have been used:  *
1331  *       m_charm = 1.5 GeV/c**2, m_bottom = 4.75 GeV/c**2 and          *
1332  *       m_top = 180 GeV/c**2.                                         *
1333  *                                                                     *
1334  *     The alpha(s) value can be obtained via a call to:               *
1335  *       FUNCTION ALPHAS2(SCALE)                                       *
1336  *                                                                     *
1337  *     The user has to provide the following INPUT:                    *
1338  *                                                                     *
1339  *       SCALE  =  QCD scale in GeV                                    *
1340  *                                                                     *
1341  *     The function ALPHAS2 returns the following OUTPUT:              *
1342  *                                                                     *
1343  *       ALPHAS2 =  alpha strong to second order,                      *
1344  *                                                                     *
1345  *  if LO not equal to one. For those structure functions, for which   *
1346  *  the evolution is done to leading order only, alpha(s) to first     *
1347  *  order is returned.                                                 *
1348  *                                                                     *
1349  *     The same subroutine                                             *
1350  *                                                                     *
1351  *       SUBROUTINE PDFSET(PARM,VALUE)                                 *
1352  *                                                                     *
1353  *  as described in Section 2.1 should be used to change the default   *
1354  *  values of the variables NPTYPE, NGROUP, NSET, NFL, LO, TMAS,       *
1355  *  QCDL4, QCDL5, XMIN, XMAX, Q2MIN and Q2MAX.                         *
1356  *                                                                     *
1357  *     The internal COMMON block                                       *
1358  *                                                                     *
1359  *       COMMON/W50512/ QCDL4,QCDL5                                    *
1360  *                                                                     *
1361  *  where                                                              *
1362  *                                                                     *
1363  *       QCDL4  = QCD scale, Lambda_4(QCD), in GeV for four flavours   *
1364  *       QCDL5  = QCD scale, Lambda_5(QCD), in GeV for five flavours   *
1365  *                corresponding to QCDL4                               *
1366  *                                                                     *
1367  *  provides the actual value of Lambda_4(QCD) and Lambda_5(QCD) used  *
1368  *  in the alpha(s) calculation for four and five flavours, respectiv- *
1369  *  ly, for each set of structure functions.                           *
1370  *                                                                     *
1371  *                                                                     *
1372  *                                                                     *
1373  *                                                                     *
1374  *                                                                     *
1375  *                                                                     *
1376  *                                                                     *
1377  *                                                                     *
1378  *                                                                     *
1379  ******************************* - 19 - ********************************
1380 1***********************************************************************
1381  *                                                                     *
1382  *  5.  Conclusions                                                    *
1383  *                                                                     *
1384  *                                                                     *
1385  *     In the Long Write-up as an example, the NUCLEON structure       *
1386  *  function distributions at the scale Q**2 = m_W**2 for up valence   *
1387  *  lence quark is shown in Figs. 1 as a function of the parton X.     *
1388  *  The average X values for CERN and FNAL as well as for LHC and SSC  *
1389  *  energies at that scale are indicated. It can be seen from that     *
1390  *  figures that there is a large spread in shape for the different    *
1391  *  sets leading to different results in a cross section calculation.  *
1392  *  It should be pointed out that the spread from the different para-  *
1393  *  metrisations in the SAME renormalisation scheme is MUCH LARGER     *
1394  *  than the spread of parametrisations in different renormalisation   *
1395  *  schemes. This is valid for ALL parton densities, and in particular *
1396  *  at small X values !                                                *
1397  *                                                                     *
1398  *     A comparison to recent data is shown in Fig. 2, where the ratio *
1399  *  F_2(n)/F_2(p) at Q**2 = m_W**2 is displayed. Note that the older   *
1400  *  sets of structure functions, namely the set of Owens and Reya [2]  *
1401  *  and the set of Baier et al. [3] have only been implemented for     *
1402  *  completeness. These sets should not be used for cross section cal- *
1403  *  culations of any hard processes at high energies anymore. From     *
1404  *  Fig. 2 we conclude that also the other older sets of structure     *
1405  *  functions, namely the two sets of Duke and Owens [5] and the two   *
1406  *  sets of Eichten et al. [6] should be used with some care, because  *
1407  *  they do not fit the recent low energy deep-inelastic lepton-nuc-   *
1408  *  leon data from NMC and BCDMS [47]. This is not surprising because  *
1409  *  these data were not available when the sets have been made. The    *
1410  *  new set of DO 1.1 superseeds the old DO sets 1 and 2 but still     *
1411  *  gives very limited results in the low X region, even though data   *
1412  *  are available there. We conclude that the recent sets of parton    *
1413  *  densities could be preferred for all theoretical predictions in-   *
1414  *  volving structure functions, because they fit the present nucleon  *
1415  *  data best.                                                         *
1416  *                                                                     *
1417  *     In Fig. 3 the F_2(p) distribution of the recent data from Ref.  *
1418  *  [48] at Q**2 = 5 GeV**2, together with the recent data at Q**2 =   *
1419  *  15 GeV**2 from the H1 and the ZEUS experiments [49] at the ep-     *
1420  *  collider HERA is shown as a function of X. Overlayed on the same   *
1421  *  Figure are a few theoretical predictions of more recent parton     *
1422  *  parametrisations [12-16] at Q**2 = 15 GeV**2. Please note that     *
1423  *  most of these parametrisations are NOT TRUE predictions because    *
1424  *  the data are fully or partially used in the fits. From Figs. 2     *
1425  *  and 3 we conclude that the recent sets of parton densities, namely *
1426  *  the GRV set HO [14], but also the old MT set B2 [13] - both sets   * 
1427  *  are true predictions -, and the updated MRS set (H) [16], could    *
1428  *  be preferred for all theoretical predictions involving structure   *
1429  *  functions, because they fit the present data best which, at the    *
1430  *  moment,are still suffering from large uncertainties.               *
1431  *                                                                     *
1432  *     Figure 4 shows a comparison of F_2(\gamma)/alpha_(QED) at       *
1433  *  Q**2 = 100 GeV**2 of the different PHOTON structure function sets  *
1434  *  as a function of X. The charm quark density has been taken into    *
1435  *  account. The theoretical predictions are compared with experimen-  *
1436  *  tal data from the JADE experiment [50] at the same Q**2 value. Be- *
1437  *  cause of large experimental uncertainties no distinction between   *
1438  *  the different parton density sets can be made yet.                 *
1439  *                                                                     *
1440  *     The response from the Physics community has been very satisfac- *
1441  *  tory, which is encouraging us to keep up-to-date with the latest   *
1442  *  developments in this area. Therefore, please CONTINUE SENDING YOUR *
1443  *  FEEDBACK ON THE USAGE AND POSSIBLE IMPROVEMENTS TO US. Coming new  *
1444  *  sets of structure functions should be easily implemented in the    *
1445  *  package. Authors of {\bf new sets} are kindly asked to PROVIDE US  *
1446  *  with the RELEVANT INFORMATION. PLEASE RETURN ANY PROBLEMS, QUES-   *
1447  *                                                                     *
1448  ******************************* - 20 - ********************************
1449 1***********************************************************************
1450  *                                                                     *
1451  *  TIONS, SUGGESTIONS FOR IMPROVEMENTS TO THE AUTHOR OF THE PACKAGE   *
1452  *  (e-mail address: plothow@mail.cern.ch).                            *
1453  *                                                                     *
1454  *                                                                     *
1455  *                                                                     *
1456  *                                                                     *
1457  *                                                                     *
1458  *                                                                     *
1459  *  5.  Acknowledgements                                               *
1460  *                                                                     *
1461  *                                                                     *
1462  *     The author of the package would like to thank                   *
1463  *  M.A. Marquina/CERN-CN for help and support making this package     *
1464  *  available to the Physics community as part of the CERN Program     *
1465  *  Library. In addition we give many thanks to G. Folger/CERN-CN and  *
1466  *  I. McLaren/CERN-CN for thoroughly testing out the package on the   *
1467  *  different system areas.                                            *
1468  *                                                                     *
1469  *     We also would like to thank J.M. Marraffino/FNAL for the help-  *
1470  *  ful comments and the correction set which he supplied.             *
1471  *                                                                     *
1472  *     And finally we acknowledge K. Charchula/DESY who provided the   *
1473  *  source code of some of the photon structure functions which had    *
1474  *  previously been implemented in the package.                        *
1475  *                                                                     *
1476  *                                                                     *
1477  *                                                                     *
1478  *                                                                     *
1479  *                                                                     *
1480  *                                                                     *
1481  *                                                                     *
1482  *                                                                     *
1483  *                                                                     *
1484  *                                                                     *
1485  *                                                                     *
1486  *                                                                     *
1487  *                                                                     *
1488  *                                                                     *
1489  *                                                                     *
1490  *                                                                     *
1491  *                                                                     *
1492  *                                                                     *
1493  *                                                                     *
1494  *                                                                     *
1495  *                                                                     *
1496  *                                                                     *
1497  *                                                                     *
1498  *                                                                     *
1499  *                                                                     *
1500  *                                                                     *
1501  *                                                                     *
1502  *                                                                     *
1503  *                                                                     *
1504  *                                                                     *
1505  *                                                                     *
1506  *                                                                     *
1507  *                                                                     *
1508  *                                                                     *
1509  *                                                                     *
1510  *                                                                     *
1511  *                                                                     *
1512  *                                                                     *
1513  *                                                                     *
1514  *                                                                     *
1515  *                                                                     *
1516  *                                                                     *
1517  ******************************* - 21 - ********************************
1518 1***********************************************************************
1519  *                                                                     *
1520  *  References                                                         *
1521  *                                                                     *
1522  *                                                                     *
1523  *  [1] A.J.Buras and K.J.F. Gaemers : Nucl. Phys. B132 (1978) 249;    *
1524  *      BEBC WA 59 Collaboration, K. Varnell et al., Z. Phys. C36 (1987) 1.
1525  *                                                                     *
1526  *  [2] J.F.Owens and E. Reya : Phys. Rev. D17 (1978) 3003.            *
1527  *                                                                     *
1528  *  [3] R. Baier, J. Engels and B. Petersson : Z. Phys. C2 (1979) 265. *
1529  *                                                                     *
1530  *  [4] Gl"uck, E. Hoffman and E. Reya : Z. Phys. C13 (1982) 119.      *
1531  *                                                                     *
1532  *  [5] D.W. Duke and J.F.Owens : Phys. Rev. D30 (1984) 49.            *
1533  *                                                                     *
1534  *  [6] E. Eichten, I Hinchliffe, K. Lane and C. Quigg :               *
1535  *      Rev. Mod. Phys. 56 (1984) 579 and Rev. Mod. Phys. 58 (1985) 1065.
1536  *                                                                     *
1537  *  [7] M. Diemoz, F. Ferroni, E. Longo and G. Martinelli :            *
1538  *      Z. Phys. C39 (1988) 21.                                        *
1539  *                                                                     *
1540  *  [8] J.F.Owens : Phys. Lett. 266B (1991) 126.                       *
1541  *                                                                     *
1542  *  [9] A.D. Martin, R.G. Roberts and W.J. Stirling : Phys.Rev. D37 (1988) 1161;
1543  *      Phys. Lett. 206B (1988) 327 and Mod. Phys. Lett. A4 (1989) 1135.
1544  *                                                                     *
1545  * [10] P.N. Harriman, A.D. Martin, R.G. Roberts and W.J. Stirling :   *
1546  *      Phys. Rev. D42 (1990) 798 and Phys. Lett. 243B (1990) 421.     *
1547  *                                                                     *
1548  * [11] J. Kwiecinski, A.D. Martin, R.G. Roberts and W.J. Stirling :   *
1549  *      Phys. Rev. D42 (1990) 3645;                                    *
1550  *      A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1551  *      Phys. Rev. D43 (1991) 3648.                                    *
1552  *                                                                     *
1553  * [12] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1554  *      Phys. Rev. D47 (1993) 867.                                     *
1555  *                                                                     *
1556  * [13] J. Morfin and W.K. Tung : Z. Phys. C52 (1991) 13.              *
1557  *                                                                     *
1558  * [14] M. Gl"uck, E. Reya and A. Vogt : Z. Phys. C48 (1990) 471;      *
1559  *      Z. Phys. C53 (1992) 127 and Phys. Lett. 306B (1993) 391.       *
1560  *                                                                     *
1561  * [15] P. Aurenche et al. : Phys. Rev. D39 (1989) 3275.               *
1562  *                                                                     *
1563  * [16] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1564  *      Phys. Lett. 306B (1993) 147 and Erratum-ibid. 309B (1993) 492; *
1565  *      Durham Preprint, DTP/93/86 (1993).                             *
1566  *                                                                     *
1567  * [17] E.L. Berger and R. Meng : Phys. Lett. 304B (1993) 318;         *
1568  *      CERN-TH 6739/92; ANL-HEP-CP-92-108 and                         *
1569  *      E.L. Berger, R. Meng and J. Qiu : ANL-HEP-CP-92-79.            *
1570  *                                                                     *
1571  * [18] CTEQ collaboration, J. Botts et al. : Phys. Lett. 304B (1993) 159.
1572  *                                                                     *
1573  * [19] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1574  *      Phys. Rev. D50 (1994) 6734.                                    *
1575  *                                                                     *
1576  * [20] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1577  *      Phys. Lett. 354B (1995) 155;                                   *
1578  *      A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1579  *      RAL Preprint, RAL/95-021 (1995).                               *
1580  *                                                                     *
1581  * [21] CTEQ collaboration, MSUHEP-41024.                              *
1582  *                                                                     *
1583  * [22] M. Gl"uck, E. Reya and A. Vogt : Z. Phys. C67 (1995) 433.      *
1584  *                                                                     *
1585  *                                                                     *
1586  ******************************* - 22 - ********************************
1587 1***********************************************************************
1588  *                                                                     *
1589  * [23] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1590  *      Phys. Rev. D51 (1995) 4756.                                    *
1591  *                                                                     *
1592  * [24] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1593  *      Phys. Lett. 356B (1995) 89.                                    *
1594  *                                                                     *
1595  * [25] E.W.N. Glover, A.D. Martin, R.G. Roberts and W.J. Stirling :   *
1596  *      Phys. Lett. 381B (1996) 353.                                   *
1597  *                                                                     *
1598  * [26] A.D. Martin, R.G. Roberts and W.J. Stirling :                  *
1599  *      Durham Preprint, DTP/96/44 (1996).                             *
1600  *                                                                     *
1601  * [27] CTEQ collaboration, MSUHEP-60416, CTEQ-604.                    *
1602  *                                                                     *
1603  * [28] M. Gl"uck, E. Reya, M. Stratmann and A. Vogelsang :            *
1604  *      Phys. Lett. 359B (1995) 201;                                   *
1605  *      Phys. Rev. D53 (1995) 4775.                                    *
1606  *                                                                     *
1607  * [29] J.F.Owens : Phys. Rev. D30 (1984) 943.                         *
1608  *                                                                     *
1609  * [30] P. Aurenche et al. : Phys. Lett. 233B (1989) 517.              *
1610  *                                                                     *
1611  * [31] P.J. Sutton, A.D. Martin, R.G. Roberts and W.J. Stirling :     *
1612  *      Phys. Rev. D45 (1992) 2349.                                    *
1613  *                                                                     *
1614  * [32] M. Gl"uck, E. Reya and A. Vogt : Z. Phys. C53 (1992) 651.      *
1615  *                                                                     *
1616  * [33] D.W. Duke and J.F.Owens : Phys. Rev. D26 (1982) 1600.          *
1617  *                                                                     *
1618  * [34] M. Drees and K. Grassie : Z. Phys. C28 (1985) 451.             *
1619  *                                                                     *
1620  * [35] H. Abramowicz, K. Charchula and A. Levy :                      *
1621  *      Phys. Lett. 269B (1991) 458.                                   *
1622  *                                                                     *
1623  * [36] K. Hagiwara et al. : Phys. Rev. D51 (1995) 3197.               *
1624  *                                                                     *
1625  * [37] L.E. Gordon and J.K. Storrow : Z. Phys. C56 (1992) 307.        *
1626  *                                                                     *
1627  * [38] M. Gl"uck, E. Reya and A. Vogt : Phys. Rev. D46 (1992) 1973    *
1628  *      and Phys. Rev. D45 (1992) 3986.                                *
1629  *                                                                     *
1630  * [39] P. Aurenche et al. : Z. Phys. C56 (1992) 589.                  *
1631  *                                                                     *
1632  * [40] P. Aurenche M. Fontannaz, J.Ph. Guillet : Z. Phys. C64 (1994) 621.
1633  *                                                                     *
1634  * [41] G.A. Schuler and T. Sjostrand : Z. Phys. C68 (1995) 607 and    *
1635  *      Phys. Lett. 276B (1996) 193.                                   *
1636  *                                                                     *
1637  * [42] M. Gl"uck, E. Reya, M. Stratmann : Phys. Rev. D51 (1995) 3220. *
1638  *      Phys. Rev. D53 (1995) 4775.                                    *
1639  *                                                                     *
1640  * [43] L.E. Gordon and J.K. Storrow : ANL-HEP-PR-96-33 and MC-TH-96-16.
1641  *                                                                     *
1642  * [44] G. Altarelli, R.K. Ellis and G. Martinelli :                   *
1643  *      Nucl. Phys. B143 (1978) 521 and B157 (1979) 461.               *
1644  *                                                                     *
1645  * [45] H. Plothow-Besch, 'PDFLIB: Structure Functions and alpha(s)    *
1646  *      Calculations', User's Manual - Version 1.00, W5051 PDFLIB,     *
1647  *      1991.03.21, CERN-PPE.                                          *
1648  *      H. Plothow-Besch, 'PDFLIB: a library of all available parton   *
1649  *      density functions of the nucleon, the pion and the photon      *
1650  *      and the corresponding alpha(s) calculations',                  *
1651  *      Comp. Phys. Comm. 75 (1993) 396-416;                           *
1652  *      H. Plothow-Besch, 'The Parton Distribution Function Library',  *
1653  *      Int. J. Mod. Phys. A10 (1995) 2901.                            *
1654  *                                                                     *
1655  ******************************* - 23 - ********************************
1656 1***********************************************************************
1657  *                                                                     *
1658  * [46] Review of Particle Properties, June 1992,                      *
1659  *      Phys. Rev. D45 (1992), Part. II, p. III.54.                    *
1660  *                                                                     *
1661  * [47] BCDMS Collaboration, A.C. Benvenuti et al. :                   *
1662  *      Phys. Lett. 237B (1990) 592 and Phys. Lett. 237B (1990) 599;   *
1663  *      EMC Collaboration, M. Arneodo et al. : Nucl. Phys. B333 (1990) 1;
1664  *      NMC Collaboration, D. Allasia et al. : Phys. Lett. 249B (1990) 366;
1665  *                         P. Amaudruz et al. : Nucl. Phys. B371 (1992) 3.
1666  *                                                                     *
1667  * [48] NMC Collaboration, P. Amaudruz et al. : Phys. Lett. 295B (1992) 159.
1668  *                                                                     *
1669  * [36] H1 Collaboration, I. Abt et al. : Nucl. Phys. B407 (1993) 515; *
1670  *      ZEUS Collaboration, M. Derrick et al. : Phys. Lett. 316B (1993) 412.
1671  *                                                                     *
1672  * [50] JADE Collaboration, W. Bartel et al. : Z. Phys. C24 (1984) 231.*
1673  *                                                                     *
1674  * [51] PAW, CERN Program Library Entry Q121, Long Write-up;           *
1675  *      R. Brun, O. Couet, C. Vandoni and P Zanarini;                  *
1676  *      see also to References therein.                                *
1677  *                                                                     *
1678  *                                                                     *
1679  *                                                                     *
1680  *                                                                     *
1681  *                                                                     *
1682  *                                                                     *
1683  *                                                                     *
1684  *                                                                     *
1685  *                                                                     *
1686  *                                                                     *
1687  *                                                                     *
1688  *                                                                     *
1689  *                                                                     *
1690  *                                                                     *
1691  *                                                                     *
1692  *                                                                     *
1693  *                                                                     *
1694  *                                                                     *
1695  *                                                                     *
1696  *                                                                     *
1697  *                                                                     *
1698  *                                                                     *
1699  *                                                                     *
1700  *                                                                     *
1701  *                                                                     *
1702  *                                                                     *
1703  *                                                                     *
1704  *                                                                     *
1705  *                                                                     *
1706  *                                                                     *
1707  *                                                                     *
1708  *                                                                     *
1709  *                                                                     *
1710  *                                                                     *
1711  *                                                                     *
1712  *                                                                     *
1713  *                                                                     *
1714  *                                                                     *
1715  *                                                                     *
1716  *                                                                     *
1717  *                                                                     *
1718  *                                                                     *
1719  *                                                                     *
1720  *                                                                     *
1721  *                                                                     *
1722  *                                                                     *
1723  *                                                                     *
1724  ******************************* - 24 - ********************************
1725 1***********************************************************************
1726  *                                                                     *
1727  *  Appendix A                                                         *
1728  *                                                                     *
1729  *                                                                     *
1730  *     As an example how to use the package, the FORTRAN code to ob-   *
1731  *  tain Fig. 1 of the Long Write-up which shows the parton density    *
1732  *  function distributions for the up valence quark as a function of   *
1733  *  the parton X for all sets of structure functions is given below:   *
1734  *                                                                     *
1735  *      PROGRAM PDFUPV                                                 *
1736  *  C define the maximum number of PDF sets, the name and the cross reference
1737  *      PARAMETER (NPTYMX = 3, NGRMAX = 9, NSETMX = 58)                *
1738  *      COMMON /W505120/ NPGSMX(NPTYMX,NGRMAX),NSETFL(NPTYMX,NGRMAX,NSETMX)
1739  *      CHARACTER*8 SFNAME(NPTYMX,NGRMAX,NSETMX)                       *
1740  *      COMMON /W505110/ SFNAME                                        *
1741  *      COMMON /W505122/ MODECR(NPTYMX,NGRMAX,NSETMX)                  *
1742  *  C define HBOOK settings                                            *
1743  *      PARAMETER (NHBMEM = 500000)                                    *
1744  *      COMMON /PAWC/ HMEM(NHBMEM)                                     *
1745  *      PARAMETER (NB=900, ID=100)                                     *
1746  *  C define DOUBLE PRECISION variables for calling sequence to STRUCTM*
1747  *      DOUBLE PRECISION DX,DSCALE                                     *
1748  *      DOUBLE PRECISION DUPV,DDNV,DUSEA,DDSEA,DSTR,DCHM,DBOT,DTOP,DGL *
1749  *      DOUBLE PRECISION ALF,ALPHAS2                                   *
1750  *      REAL    X, SCALE, UPV, DNV, USEA, DSEA, STR, CHM, BOT, TOP, GL *
1751  *      COMMON/W50516/ FIRST                                           *
1752  *      LOGICAL FIRST                                                  *
1753  *      CHARACTER*20 PARM(20)                                          *
1754  *      DOUBLE PRECISION VAL(20)                                       *
1755  *      DATA SCALE/80.140/                                             *
1756  *      DATA X00/0.002/,DX0/0.001/,XLOW/0.0015/,XUP/0.9015/            *
1757  *  C                                                                  *
1758  *      CALL HLIMIT(NHBMEM)                                            *
1759  *      DSCALE=SCALE                                                   *
1760  *  C first call to PDFSET to initialize COMMON/W505120/,/W505120/ and /W505122/
1761  *      PARM(1) = 'Init0'                                              *
1762  *      VAL(1)  = 0.D0                                                 *
1763  *      CALL PDFSET(PARM,VAL)                                          *
1764  *  C loop over all existing sets of Nucleon structure functions (SF)  *
1765  *      NPTYPE = 1                                                     *
1766  *      NHB = 0                                                        *
1767  *      DO 20 IGR = 1,NGRMAX                                           *
1768  *         IF(NPGSMX(NPTYPE,IGR).EQ.0) GOTO 20                         *
1769  *         DO ISET = 1,NPGSMX(NPTYPE,IGR)                              *
1770  *  C book histograms for each set of SF separately                    *
1771  *         NHB = NHB + 1                                               *
1772  *         CALL HBOOK1(ID+NHB,'U Valence quark ',NB,XLOW,XUP,0.)       *
1773  *  C force label printing for each set of SF (not only the 1st)       *
1774  *         FIRST = .TRUE.                                              *
1775  *  C define and set parameters                                        *
1776  *         PARM(1) = 'Nptype'                                          *
1777  *         VAL(1)  = NPTYPE                                            *
1778  *         PARM(2) = 'Ngroup'                                          *
1779  *         VAL(2)  = IGR                                               *
1780  *         PARM(3) = 'Nset'                                            *
1781  *         VAL(3)  = ISET                                              *
1782  *         CALL PDFSET(PARM,VAL)                                       *
1783  *  C loop over all X bins                                             *
1784  *        DO 10 I=1,NB                                                 *
1785  *           X = X00 + (I-1)*DX0                                       *
1786  *           DX = X                                                    *
1787  *           IF(X.LT.XLOW .OR. X.GT.XUP) GOTO 10                       *
1788  *           CALL STRUCTM(DX,DSCALE,                                   *
1789  *      +           DUPV,DDNV,DUSEA,DDSEA,DSTR,DCHM,DBOT,DTOP,DGL)     *
1790  *           UPV=DUPV                                                  *
1791  *           IF(X.GT.0.499 .AND. X.LE.0.500) WRITE(6,1000) X,SCALE,UPV *
1792  *                                                                     *
1793  ******************************* - 25 - ********************************
1794 1***********************************************************************
1795  *                                                                     *
1796  *  Example of Fig. 1, cont'd                                          *
1797  *                                                                     *
1798  *  1000     FORMAT(/,'  X= ',F6.4,'  Q= ',F6.3,'  UPV= ',8.4)         *
1799  *           CALL HF1(ID+NHB,X,UPV)                                    *
1800  *  10    CONTINUE                                                     *
1801  *  C get alpha(s) for selected set of SF at Q = SCALE                 *
1802  *        ALF = ALPHAS2(DSCALE)                                        *
1803  *        WRITE(6,4000) NPTYPE,IGR,ISET,SFNAME(NPTYPE,IGR,ISET),       *
1804  *      +                  MODECR(NPTYPE,IGR,ISET),NSF                 *
1805  *        WRITE(6,4001) DSCALE,ALF                                     *
1806  *  4000  FORMAT(/,'  Nptype = ',I1,'  Ngroup = ',I1,'  Nset = ',I2,   *
1807  *      +          '  Name = "'A8,'"  CrMode = ',I3,'  HBId = ',I3)    *
1808  *  4001  FORMAT(1H ,' SCALE  = ',F8.4,'   alpha(s) = ',F6.4)          *
1809  *  C get error summary for each set of SF                             *
1810  *        CALL PDFSTA                                                  *
1811  *     ENDDO                                                           *
1812  *  20 CONTINUE                                                        *
1813  *  C                                                                  *
1814  *     STOP                                                            *
1815  *     END                                                             *
1816  *                                                                     *
1817  *                                                                     *
1818  *                                                                     *
1819  *                                                                     *
1820  *                                                                     *
1821  *     This code will produce the following output:                    *
1822  *                                                                     *
1823  *                                                                     *
1824  *         1. HBOOK Output :                                           *
1825  *                                                                     *
1826  *     one histogram for each set of structure functions. The histo-   *
1827  *  gram output has then been accessed, and each histogram has been    *
1828  *  superimposed on one single frame using the PAW package [51] to     *
1829  *  obtain Fig. 1 of the Long Write-up.                                *
1830  *                                                                     *
1831  *                                                                     *
1832  *         2. Print Output (Example is given for NPTYPE = 1,           *
1833  *  NGROUP = 3, NSET = 41 only :                                       *
1834  *                                                                     *
1835  * ___________________________________________________________________ *
1836  *|                                                                   |*
1837  *| 1*****  PDFLIB Version:  7.09  Released on  970702  at  16.05  in |*
1838  *| the CERN Computer Program Library  W5051  *****                   |*
1839  *|  *****  Library compiled on  970702  at  16.05   *****            |*
1840  *|                                                                   |*
1841  *| Nucleon PDFs:  Ngroup = 3,  Nset = 41,  for MRS Set (G) Structure |*
1842  *| ------------------------------------------------------------------|*
1843  *|                                                         Functions |*
1844  *|                                                         --------- |*
1845  *|                                                                   |*
1846  *| X= 0.5000  Q= 80.140  UPV=   0.1176                               |*
1847  *|                                                                   |*
1848  *| Nptype = 1  Ngroup = 3  Nset = 41 Name = "MRS-G   "  CrMode =  -1  HBId = 60
1849  *| Scale  =  80.1400  alpha(s) =  0.1154                             |*
1850  *|                                                                   |*
1851  *| PDFLIB : Summary from PDFSTA                                      |*
1852  *| Nptype = 1  Ngroup = 3  Nset = 41  Name = "MRS-G   "  CrMode =  -1|*
1853  *| Nfl    = -5  LO = 2  Tmas = 180.00 GeV/c**2                       |*
1854  *| QCDL4  = 0.2550 GeV,  QCDL5 =   0.1708 GeV                        |*
1855  *| Xmin   = 0.10E-04,  Xmax =  0.99999E+00,  Q2min =  5.000 (GeV/c)**2,
1856  *|   Q2max =  0.27E+10 (GeV/c)**2                                    |*
1857  *|                                                                   |*
1858  *| PDFSTA:    NO errors occured                                      |*
1859  *|___________________________________________________________________|*
1860  *                                                                     *
1861  *                                                                     *
1862  ******************************* - 26 - ********************************
1863 1***********************************************************************
1864  *                                                                     *
1865  *  Appendix B                                                         *
1866  *                                                                     *
1867  *                                                                     *
1868  *     A list of subroutines, functions, COMMON blocks and parameters  *
1869  *  of RELEVANCE to the user which are used in PDFLIB is given below:  *
1870  *                                                                     *
1871  *                                                                     *
1872  *     List of relevant subprograms and COMMON blocks in PDFLIB:       *
1873  *                                                                     *
1874  *  _________________________________________________________________  *
1875  *  |                                                               |  *
1876  *  |  (S = Subroutine, F = Function, C = COMMON, P = Parameter)    |  *
1877  *  |                                                               |  *
1878  *  | ------------------------------------------------------------- |  *
1879  *  |                                                               |  *
1880  *  |  S  PDFSET   : to set all parameters for PDFLIB               |  *
1881  *  |  S  STRUCTF  : to access PDFLIB with output in PDFLIB format  |  *
1882  *  |  S  STRUCTM  : to access PDFLIB with output in PDFLIB format  |  *
1883  *  |                (with u_bar not equal to d_bar)                |  *
1884  *  |  S  STRUCTP  : to access PDFLIB with output in PDFLIB format  |  *
1885  *  |                for PHOTON structure functions                 |  *
1886  *  |  S  PFTOPDG  : to access PDFLIB with output in PDG format     |  *
1887  *  |  S  PDFSTA   : to print summary of parameters and error statistics
1888  *  |  F  ALPHAS2  : to calculate alpha(s) to second order QCD      |  *
1889  *  |                                                               |  *
1890  *  |  C  W50510   : IFLPRT - to set print flag                     |  *
1891  *  |  C  W50511   : NPTYPE,NGROUP,NSET,MODE,NFL,LO,TMAS            |  *
1892  *  |                - to select a structure function set, to       |  *
1893  *  |                define number of flavours, flag for leading    |  *
1894  *  |                order and value for the mass of the top quark  |  *
1895  *  |  C  W50512   : QCDL4,QCDL5 - contains Lambda_4(QCD) and       |  *
1896  *  |                Lambda_5(QCD) (in GeV)                         |  *
1897  *  |  C  W50513   : XMIN,XMAX,Q2MIN,Q2MAX - contains minimum and   |  *
1898  *  |                maximum values of X and Q**2                   |  *
1899  *  |  C  W50516   : FIRST - to force printing name of structure    |  *
1900  *  |                function set in case of multiple choices       |  *
1901  *  |  C  W50519   : NEWVER - flags NEW/OLD version of PDFLIB format|  *
1902  *  |  C  W505110  : SFNAME - contains NAME (CHARACTER*8 array with |  *
1903  *  |                dimension SFNAME(NPTYMX,NGRMAX,NSETMX)) for    |  *
1904  *  |                each set of PDFs                               |  *
1905  *  |  C  W505120  : NPGSMX(NPTYMX,NGRMAX),NSETFL(NPTYMX,NGRMAX,NSETMX)*
1906  *  |                - contains maximum number of stucture functions|  *
1907  *  |                per particle type and author group, and FLAG   |  *
1908  *  |                for retracted PDF set (NSETFL(I,J,K) = 0),     |  *
1909  *  |  C  W505121  : NPTYCR(MODEMX),NGROCR(MODEMX),NSETCR(MODEMX)   |  *
1910  *  |                - cross reference to the NPTYPE, NGROUP and    |  *
1911  *  |                NSET value (NEW format) for a given MODE       |  *
1912  *  |                value (OLD format)                             |  *
1913  *  |  C  W505122  : MODECR(NPTYMX,NGRMAX,NSETMX) - cross reference |  *
1914  *  |                to the MODE value (OLD format) for a given     |  *
1915  *  |                NPTYPE, NGROUP and NSET value (NEW format)     |  *
1916  *  |  P  W5051P2  : MODEMX - maximum number of structure function  |  *
1917  *  |                sets in the OLD PDFLIB format                  |  *
1918  *  |              : NPTYMX,NGRMAX,NSETMX - maximum number of       |  *
1919  *  |                structure function sets in the NEW PDFLIB      |  *
1920  *  |                format for particle type, author group number  |  *
1921  *  |                and number of sets within an author group      |  *
1922  *  |  P  W5051P7  : L6 - to define logical print unit number       |  *
1923  *  |_______________________________________________________________|  *
1924  *                                                                     *
1925  *                                                                     *
1926  *                                                                     *
1927  *                                                                     *
1928  *                                                                     *
1929  *                                                                     *
1930  *                                                                     *
1931  ******************************* - 27 - ********************************
1932 1***********************************************************************
1933  *                                                                     *
1934  *  Appendix C                                                         *
1935  *                                                                     *
1936  *                                                                     *
1937  *     A complete list of subroutines, functions, COMMON blocks and    *
1938  *  parameters which are used in PDFLIB is given below:                *
1939  *                                                                     *
1940  *                                                                     *
1941  *     Complete list of subprograms and COMMON blocks in PDFLIB:       *
1942  *                       (in alphabetical order)                       *
1943  *                                                                     *
1944  *  _________________________________________________________________  *
1945  *  |                                                               |  *
1946  *  |  (S = Subroutine, F = Function, C = COMMON, P = Parameter)    |  *
1947  *  |                                                               |  *
1948  *  | ------------------------------------------------------------- |  *
1949  *  |                                                               |  *
1950  *  |  S  ABFKW1   : ABFKW SF set 1 in the pion (NP=2,NG=6,NS=1)    |  *
1951  *  |  S  ABFKW2   : ABFKW SF set 2 in the pion (NP=2,NG=6,NS=2)    |  *
1952  *  |  S  ABFKW3   : ABFKW SF set 3 in the pion (NP=2,NG=6,NS=3)    |  *
1953  *  |  S  ACFGP1   : ACFGP SF set 1 in the photon (NP=3,NG=6,NS=1)  |  *
1954  *  |  S  ACFGP2   : ACFGP SF set 1 in the photon (mc) (NP=3,NG=6,NS=2)*
1955  *  |  F  AFCPLU   : to get PD with massive charm for ACFGP         |  *
1956  *  |  F  AFGETFV  : to interpolate PDs in grid for ACFGP           |  *
1957  *  |  F  AFGIN2   : to interpolate PDs in grid for ACFGP           |  *
1958  *  |  F  AFGINT   : to interpolate PDs in grid for ACFGP           |  *
1959  *  |  F  AFPOLIN  : to interpolate PDs in grid for ACFGP           |  *
1960  *  |  F  AFRATIN  : to interpolate PDs in grid for ACFGP           |  *
1961  *  |  F  ALPHAS2  : to calculate alpha(s) to second order QCD      |  *
1962  *  |  F  AUGETFV  : to interpolate logarithmically PDs in grid     |  *
1963  *  |  S  AURGAM   : to get the PDs in the photon for ACFGP-G       |  *
1964  *  |  S  AURPI1   : to get the PDs in the pion for ABFKW-P set 1   |  *
1965  *  |  S  AURPI2   : to get the PDs in the pion for ABFKW-P set 2   |  *
1966  *  |  S  AURPI3   : to get the PDs in the pion for ABFKW-P set 3   |  *
1967  *  |  S  AURPR    : to get the PDs in the nucleon for ABFOW        |  *
1968  *  |  F  BBETA    : DOUBLE PRECISION beta function using DGAMMA    |  *
1969  *  |  F  BETA     : SINGLE PRECISION beta function using GAMMA     |  *
1970  *  |  S  BXF3     : BEP SF set for up and down valence quarks      |  *
1971  *  |  S  BXGLUE   : BEP SF set for gluons                          |  *
1972  *  |  S  BXQBAR   : BEP SF set for antiquarks                      |  *
1973  *  |  F  CTQ1OPD  : CTEQ SF sets 1M, 1MS, 1ML, 1D and 1L           |  *
1974  *  |  F  CTQ1OPF  : Description of CTEQ sets 1M, 1MS, 1ML, 1D, 1L  |  *
1975  *  |  F  CTQ1PD   : CTEQ SF sets 1M, 1MS, 1ML, 1D and 1L           |  *
1976  *  |  F  CTQ1PF   : Description of CTEQ sets 1M, 1MS, 1ML, 1D, 1L  |  *
1977  *  |  F  CTQ2OPD  : CTEQ SF sets 2M, 2MS, 2ML, 2D and 2L           |  *
1978  *  |  F  CTQ2OPF  : Description of CTEQ sets 2M, 2MS, 2ML, 2D, 2L  |  *
1979  *  |  S  CTQ2OPS  : CTEQ SF sets 2M, 2MS, 2ML, 2D and 2L           |  *
1980  *  |  F  CTQ2PPD  : CTEQ SF sets 2pM, 2pMS, 2pML, 2pD and 2pL      |  *
1981  *  |  F  CTQ2PPF  : Description of CTEQ sets 2pM, 2pMS, 2pML, 2pD, 2pL*
1982  *  |  S  CTQ2PPS  : CTEQ SF sets 2pM, 2pMS, 2pML, 2pD and 2pL      |  *
1983  *  |  F  CTQ3PD   : CTEQ SF sets 3L, 3M and 3D                     |  *
1984  *  |  S  CTQ3PDS  : CTEQ SF sets 3L, 3M and 3D                     |  *
1985  *  |  F  CTQ3PF   : Description of CTEQ sets 3L, 3M and 3D         |  *
1986  *  |  F  CTQ4Fn   : Description of CTEQ sets 4L, 4D, 4A1-A5, 4HJ and 4lQ
1987  *  |  F  CTQ4PnX  : CTEQ SF sets 4L, 4D, 4A1-A5, 4HJ and 4lQ       |  *
1988  *  |  S  CTQ4RA1  : Parameters of CTEQ set 4 A1                    |  *
1989  *  |  S  CTQ4RA2  : Parameters of CTEQ set 4 A2                    |  *
1990  *  |  S  CTQ4RA4  : Parameters of CTEQ set 4 A4                    |  *
1991  *  |  S  CTQ4RA5  : Parameters of CTEQ set 4 A5                    |  *
1992  *  |  S  CTQ4RD   : Parameters of CTEQ set 4 D                     |  *
1993  *  |  S  CTQ4RHJ  : Parameters of CTEQ set 4 HJ                    |  *
1994  *  |  S  CTQ4RL   : Parameters of CTEQ set 4 L                     |  *
1995  *  |  S  CTQ4RM   : Parameters of CTEQ set 4 M                     |  *
1996  *  |  S  CTQ4RlQ  : Parameters of CTEQ set 4 lQ                    |  *
1997  *  |  F  DBFINT   : to interpolate linearly PDs in grid (double precision)
1998  *  |  S  DFLM1    : interface to DFLM 160 (NP=1,NG=2,NS=7)         |  *
1999  *  |_______________________________________________________________|  *
2000  ******************************* - 28 - ********************************
2001 1***********************************************************************
2002  *  _________________________________________________________________  *
2003  *  |  Complete list of subprograms, cont'd                         |  *
2004  *  |                                                               |  *
2005  *  |  S  DFLM2    : interface to DFLM 260 (NP=1,NG=2,NS=8)         |  *
2006  *  |  S  DFLM3    : interface to DFLM 360 (NP=1,NG=2,NS=9)         |  *
2007  *  |  S  DFLM4    : interface to DFLM soft valence quarks (NP=1,NG=2,NS=1)
2008  *  |  S  DFLM5    : interface to DFLM hard valence quarks (NP=1,NG=2,NS=2)
2009  *  |  S  DFLM6    : interface to DFLM soft gluons (NP=1,NG=2,NS=3) |  *
2010  *  |  S  DFLM7    : interface to DFLM hard gluons (NP=1,NG=2,NS=4) |  *
2011  *  |  S  DFLM8    : interface to DFLM LO average fit (NP=1,NG=2,NS=5) *
2012  *  |  S  DFLM9    : interface to DFLM NLL average fit (NP=1,NG=2,NS=6)*
2013  *  |  S  DGPHO1   : DG SF set 1 in the photon (NP=3,NG=2,NS=1)     |  *
2014  *  |  S  DGPHO2   : DG SF set 2 in the photon (NP=3,NG=2,NS=2)     |  *
2015  *  |  S  DGPHO3   : DG SF set 3 in the photon (NP=3,NG=2,NS=3)     |  *
2016  *  |  S  DGPHO4   : DG SF set 4 in the photon (NP=3,NG=2,NS=4)     |  *
2017  *  |  S  DOPHO1   : DO SF set 1 in the photon (NP=3,NG=1,NS=1)     |  *
2018  *  |  S  DOPHO2   : DO SF set 2 in the photon (NP=3,NG=1,NS=2)     |  *
2019  *  |  F  DPOLIN   : to interpolate PDs in grid (DOUBLE PRECISION)  |  *
2020  *  |  S  FXAVER   : DFLM SF set of LO central average fit          |  *
2021  *  |  S  FXG160   : DFLM SF set of NLL with QCDL4 = 160            |  *
2022  *  |  S  FXG260   : DFLM SF set of NLL with QCDL4 = 260            |  *
2023  *  |  S  FXG360   : DFLM SF set of NLL with QCDL4 = 360            |  *
2024  *  |  S  FXGHAR   : DFLM SF set of LO hard gluon                   |  *
2025  *  |  S  FXGSOF   : DFLM SF set of LO soft gluon                   |  *
2026  *  |  S  FXNLLA   : DFLM SF set of NLL central average fit         |  *
2027  *  |  S  FXVHAR   : DFLM SF set of LO hard valence                 |  *
2028  *  |  S  FXVSOF   : DFLM SF set of LO soft valence                 |  *
2029  *  |  F  GAMFUN   : to calculate GAMMA funct. in either SP or DP prec.*
2030  *  |  F  GAMMADO  : to calculate GAMMA funct. in SP (Hastings)     |  *
2031  *  |  F  GHRDV    : GHR SF set for down quarks                     |  *
2032  *  |  F  GHRGL    : GHR SF set for gluons                          |  *
2033  *  |  F  GHRUV    : GHR SF set for up quarks                       |  *
2034  *  |  F  GHRXI    : GHR SF set for antiquarks                      |  *
2035  *  |  F  GHRXS    : GHR SF set for strange quarks                  |  *
2036  *  |  F  GR94FV   : GRV94 SF set for up + down valence quarks + gluons*
2037  *  |  F  GR94FW   : GRV94 SF set for antiquarks                    |  *
2038  *  |  F  GR94FWS  : GRV94 SF set for strange quarks                |  *
2039  *  |  F  GRSF1    : GRS SF set part1 in the photon                 |  *
2040  *  |  F  GRSF2    : GRS SF set part2 in the photon                 |  *
2041  *  |  S  GRSGALO  : GRS SF set of LO in the photon (NP=3,NG=5,NS=4)|  *
2042  *  |  S  GRSVH1   : GRSV SF set of pol. NLL standard (NP=1,NG=5,NS=10)*
2043  *  |  S  GRSVH2   : GRSV SF set of pol. NLL valence (NP=1,NG=5,NS=11) *
2044  *  |  S  GRSVL1   : GRSV SF set of pol. LO standard (NP=1,NG=5,NS=8)  *
2045  *  |  S  GRSVL2   : GRSV SF set of pol. LO valence (NP=1,NG=5,NS=9)|  *
2046  *  |  S  GRV94DI  : GRV94 SF set of DIS in the nucleon (NP=1,NG=5,NS=7)
2047  *  |  S  GRV94HO  : GRV94 SF set of MS_bar in the nucleon (NP=1,NG=5,NS=6)
2048  *  |  S  GRV94LO  : GRV94 SF set of LO in the nucleon (NP=1,NG=5,NS=5)*
2049  *  |  F  GRVFGP   : GRV SF set for gluons in the pion              |  *
2050  *  |  F  GRVFQBP  : GRV SF set for s, c and b quarks in the pion   |  *
2051  *  |  F  GRVFV    : GRV SF set for up + down valence quarks        |  *
2052  *  |  F  GRVFVP   : GRV SF set for valence quarks in the pion      |  *
2053  *  |  F  GRVFW    : GRV SF set for antiquarks and gluons           |  *
2054  *  |  F  GRVFWS   : GRV SF set for strange, charm and bottom quarks|  *
2055  *  |  S  GRVGAH0  : GRV SF set lead. terms of NLL in the photon (NP=3,NG=5,NS=1
2056  *  |  S  GRVGAHO  : GRV SF set of NLL in the photon (NP=3,NG=5,NS=2)  *
2057  *  |  S  GRVGALO  : GRV SF set of LO in the photon (NP=3,NG=5,NS=3)|  *
2058  *  |  F  GRVGF    : GRV SF set for u and d quarks and gluons in the photon
2059  *  |  F  GRVGFS   : GRV SF set for s, c and b quarks in the photon |  *
2060  *  |  S  GRVHO    : GRV SF set of NLL (NP=1,NG=5,NS=3)             |  *
2061  *  |  S  GRVLO    : GRV SF set of LO (NP=1,NG=5,NS=4)              |  *
2062  *  |  S  GRVPIHO  : GRV SF set of NLL in the pion (NP=2,NG=5,NS=1) |  *
2063  *  |  S  GRVPILO  : GRV SF set of LO in the pion (NP=2,NG=5,NS=2)  |  *
2064  *  |  S  GSXCOR   : to get X coordinates for SFGSHO + LO sets 1, 2 |  *
2065  *  |  S  GS2XCOR  : to get X coordinates for SFGSHO + LO 96        |  *
2066  *  |  S  GS96HO   : GS-96 SF set of HO in the photon (NP=3,NG=4,NS=4) *
2067  *  |  S  GS96LO   : GS-96 SF set of LO in the photon (NP=3,NG=4,NS=5) *
2068  *  |_______________________________________________________________|  *
2069  ******************************* - 29 - ********************************
2070 1***********************************************************************
2071  *  _________________________________________________________________  *
2072  *  |  Complete list of subprograms, cont'd                         |  *
2073  *  |                                                               |  *
2074  *  |  S  HMRS1EB  : Description of HMRS sets E, B (1.90-retracted) |  *
2075  *  |  S  HMRS2EB  : Description of HMRS sets E, B (3.90)           |  *
2076  *  |  S  HMRS3EB  : Description of HMRS sets E, B (4.90)           |  *
2077  *  |  S  HMRSGEB  : Description of HMRS sets E, E+, E- and B       |  *
2078  *  |  S  KMRSEB   : Description of KMRS sets E and B               |  *
2079  *  |  S  KMRSGEB  : Description of KMRS B0 with L=135,160,200,235  |  *
2080  *  |  S  MRSDSHD  : Description of MRS sets D0', S0', D-', (H) in DIS *
2081  *  |  S  MRSDSHP  : Description of MRS sets D0', S0', D-', (H)     |  *
2082  *  |  S  MRSEB    : Description of MRS sets E and B                |  *
2083  *  |  S  MRSEBP   : Description of MRS sets E' and B'              |  *
2084  *  |  S  NEWDO1   : DO SF set 1.1 (NP=1,NG=1,NS=10)                |  *
2085  *  |  S  PDFSET   : to set all parameters for PDFLIB               |  *
2086  *  |  S  PDFSTA   : to print summary of param. and error statistics|  *
2087  *  |  S  PDFVERS  : to get date and time of PDFLIB Library release |  *
2088  *  |  F  PDXMT    : Description of MT sets 1 to 11                 |  *
208