5 * Revision 1.4 2000/09/18 10:02:35 hristov
6 * Makefile added to PDF8
8 * Revision 1.1.1.2 1996/10/30 08:28:43 cernlib
11 * Revision 1.1.1.1 1996/04/12 15:29:24 plothow
15 #include "pdf/pilot.h"
16 C. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
18 C. * G R V - P A R A M E T R I Z A T I O N S *
20 C. * adapted by H. Plothow-Besch August 1991 *
23 C. * FOR A DETAILED EXPLANATION SEE : *
24 C. * M. GLUECK, E.REYA, A.VOGT: DO-TH 91/07 *
26 C. * THE PARAMETRIZATIONS ARE FITTED TO OUR PARTON DISTRIBUTIONS *
27 C. * FOR Q ** 2 BETWEEN MU ** 2 (= 0.25 / 0.30 GEV ** 2 IN LO *
28 C. * / HO) AND 1.E8 GEV ** 2 AND FOR X BETWEEN 1.E-5 AND 1. *
29 C. * REGIONS, WHERE THE DISTRIBUTION UNDER CONSIDERATION IS NEG- *
30 C. * LIGIBLE, I.E. BELOW ABOUT 1.E-4, WERE EXCLUDED FROM THE FIT. *
32 C. * HEAVY QUARK THRESHOLDS Q(H) = M(H) : *
33 C. * M(C) = 1.5, M(B) = 4.5, M(T) = 100 GEV *
35 C. * CORRESPONDING LAMBDA(F) VALUES FOR F ACTIVE FLAVOURS : *
36 C. * LO : LAMBDA(3) = 0.232, LAMBDA(4) = 0.200, *
37 C. * LAMBDA(5) = 0.153, LAMBDA(6) = 0.082 GEV *
38 C. * HO : LAMBDA(3) = 0.248, LAMBDA(4) = 0.200, *
39 C. * LAMBDA(5) = 0.131, LAMBDA(6) = 0.053 GEV *
41 C. * HO DISTRIBUTION REFER TO THE MS-BAR SCHEME OF BARDEEN ET AL. *
43 C. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
45 C...LO PARAMETRIZATIONS :
46 SUBROUTINE GRVLO (ZX,ZQ,ZUV,ZDV,ZUDB,ZSB,ZCB,ZBB,ZTB,ZGL)
48 #if defined(CERNLIB_DOUBLE)
51 #if defined(CERNLIB_SINGLE)
54 + ZX,ZQ,ZUV,ZDV,ZUDB,ZSB,ZCB,ZBB,ZTB,ZGL
61 S = ALOG (ALOG( MAX( MU2,Q2)/LAM2) / ALOG(MU2/LAM2))
65 NUD = 0.663 + 0.191 * S - 0.041 * S2 + 0.031 * S3
67 AGUD = -1.97 + 6.74 * S - 1.96 * S2
68 BUD = 24.4 - 20.7 * S + 4.08 * S2
69 DUD = 2.86 + 0.70 * S - 0.02 * S2
70 UDV = GRVFV (X, NUD, AKUD, AGUD, BUD, DUD)
72 ND = 0.579 + 0.283 * S + 0.047 * S2
73 AKD = 0.523 - 0.015 * S
74 AGD = 2.22 - 0.59 * S - 0.27 * S2
75 BD = 5.95 - 6.19 * S + 1.55 * S2
76 DD = 3.57 + 0.94 * S - 0.16 * S2
77 DV = GRVFV (X, ND, AKD, AGD, BD, DD)
87 AGG = 0.0 + 4.879 * S - 1.383 * S2
88 BGG = 25.92 - 28.97 * S + 5.596 * S2
89 CG = -25.69 + 23.68 * S - 1.975 * S2
90 DG = 2.537 + 1.718 * S + 0.353 * S2
91 EG = 0.595 + 2.138 * S
93 GL = GRVFW (X, S, ALG, BEG, AKG, BKG, AGG, BGG, CG, DG, EG, ESG)
95 C...X * UBAR = X * DBAR :
98 AKU = 0.412 - 0.171 * S
99 BKU = 0.566 - 0.496 * S
102 CU = 1.029 + 1.785 * S - 0.459 * S2
103 DU = 4.696 + 2.109 * S
104 EU = 3.838 + 1.944 * S
106 UDB = GRVFW (X, S, ALU, BEU, AKU, BKU, AGU, BGU, CU, DU, EU, ESU)
108 C...X * SBAR = X * S :
112 AKS = 2.082 - 0.577 * S
113 AGS = -3.055 + 1.024 * S ** 0.67
114 BS = 27.4 - 20.0 * S ** 0.154
116 EST = 4.33 + 1.408 * S
117 ESS = 8.27 - 0.437 * S
118 SB = GRVFWS (X, S, SS, ALS, BES, AKS, AGS, BS, DS, EST, ESS)
120 C...X * CBAR = X * C :
126 BC = 4.24 - 0.804 * S
127 DC = 3.46 + 1.076 * S
128 EC = 4.61 + 1.490 * S
129 ESC = 2.555 + 1.961 * S
130 CB = GRVFWS (X, S, SC, ALC, BEC, AKC, AGC, BC, DC, EC, ESC)
132 C...X * BBAR = X * B :
139 DB = 2.929 + 1.396 * S
140 EB = 4.71 + 1.514 * S
141 ESB = 4.02 + 1.239 * S
142 BB = GRVFWS (X, S, SBO, ALB, BEB, AKB, AGB, BBO, DB, EB, ESB)
144 C...X * TBAR = X * T :