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 08:28:44 cernlib
11 * Revision 1.1.1.1 1996/04/12 15:29:24 plothow
15 #include "pdf/pilot.h"
16 SUBROUTINE GRVPIHO (ZX,ZQ,ZUV,ZDV,ZUDB,ZSB,ZCB,ZBB,ZTB,ZGL)
17 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
19 * G R V - P I O N - P A R A M E T R I Z A T I O N S *
21 * FOR A DETAILED EXPLANATION SEE : *
22 * M. GLUECK, E.REYA, A.VOGT: DO-TH 91/16 *
24 * THE PARAMETRIZATIONS ARE FITTED TO THE PARTON DISTRIBUTIONS *
25 * FOR Q ** 2 BETWEEN MU ** 2 (= 0.25 / 0.30 GEV ** 2 IN LO *
26 * / HO) AND 1.E8 GEV ** 2 AND FOR X BETWEEN 1.E-5 AND 1. *
27 * REGIONS, WHERE THE DISTRIBUTION UNDER CONSIDERATION IS NEG- *
28 * LIGIBLE, I.E. BELOW ABOUT 1.E-4, WERE EXCLUDED FROM THE FIT. *
30 * HEAVY QUARK THRESHOLDS Q(H) = M(H) : *
31 * M(C) = 1.5, M(B) = 4.5, M(T) = 100 GEV *
33 * CORRESPONDING LAMBDA(F) VALUES FOR F ACTIVE FLAVOURS : *
34 * LO : LAMBDA(3) = 0.232, LAMBDA(4) = 0.200, *
35 * LAMBDA(5) = 0.153, LAMBDA(6) = 0.082 GEV *
36 * HO : LAMBDA(3) = 0.248, LAMBDA(4) = 0.200, *
37 * LAMBDA(5) = 0.131, LAMBDA(6) = 0.053 GEV *
39 * HO DISTRIBUTION REFER TO THE MS-BAR SCHEME OF BARDEEN ET AL. *
41 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
44 #if defined(CERNLIB_DOUBLE)
47 #if defined(CERNLIB_SINGLE)
50 + ZX,ZQ,ZUV,ZDV,ZUDB,ZSB,ZCB,ZBB,ZTB,ZGL
57 S = ALOG (ALOG(Q2/LAM2) / ALOG(MU2/LAM2))
61 NV = 0.456 + 0.150 * DS + 0.112 * S - 0.019 * S2
62 AKV = 0.505 - 0.033 * S
63 AGV = 0.748 - 0.669 * DS - 0.133 * S
64 DV = 0.365 + 0.197 * DS + 0.394 * S
65 VAP = GRVFVP (X, NV, AKV, AGV, DV)
71 AKG = 0.437 - 0.689 * DS
73 AGG = 1.324 - 0.441 * DS - 0.130 * S
74 BGG = -0.955 + 0.259 * S
75 CG = 1.075 - 0.302 * S
76 DG = 1.158 + 1.229 * S
78 ESG = 2.604 + 0.165 * S
79 GLP = GRVFGP(X,S, ALG, BEG, AKG, BKG, AGG, BGG, CG, DG, EG, ESG)
81 C...X * QBAR (SU(3)-SYMMETRIC SEA) :
85 AKS = -0.350 + 0.806 * S
88 DS = 2.273 + 1.438 * S
89 EST = 3.214 + 1.545 * S
90 ESS = 1.341 + 1.938 * S
91 QBP = GRVFQBP (X, S, SL, ALS, BES, AKS, AGS, BS, DS, EST, ESS)
94 C...X * CBAR = X * C :
100 BC = -1.00 + 1.40 * S
101 DC = 1.318 + 0.584 * S
102 EC = 4.45 + 1.235 * S
103 ESC = 1.496 + 1.010 * S
104 CBP = GRVFQBP (X, S, SC, ALC, BEC, AKC, AGC, BC, DC, EC, ESC)
106 C...X * BBAR = X * B :
110 AKB = 0.0 - 0.172 * S
113 DB = 1.447 + 0.485 * S
114 EB = 4.79 + 1.164 * S
115 ESB = 1.724 + 2.121 * S
116 BBP = GRVFQBP (X, S, SBO, ALB, BEB, AKB, AGB, BBO, DB, EB, ESB)
118 C...X * TBAR = X * T :