5 * Revision 1.1.1.2 1996/10/30 08:28:07 cernlib
8 * Revision 1.2 1996/10/28 14:59:26 pdflib
9 * PDFLIB new version 7.04
11 * Revision 1.1.1.1 1996/04/12 15:29:17 plothow
15 #include "pdf/pilot.h"
16 SUBROUTINE DOPHO2(DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL)
17 C********************************************************************
19 C* Parametrization of parton distribution functions *
20 C* in the photon (LO analysis) - asymptotic solution of AP eq.! *
22 C* authors: D.Duke and H.Owens (DO) *
23 C* /Phys.Rev. D26 (1982) 1600/ *
26 C* Krzysztof Charchula, DESY *
27 C* bitnet: F1PCHA@DHHDESY3 *
28 C* decnet: 13313::CHARCHULA *
31 C* H. Plothow-Besch/CERN-PPE *
33 C********************************************************************
35 #include "pdf/impdp.inc"
36 #include "pdf/expdp.inc"
38 + DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL
39 PARAMETER (ALPEM=7.29927D-3,PI=3.141592D0)
40 PARAMETER (ALAM=0.4D0)
41 DATA CQ/0.33333D0,0.66666D0,0.33333D0,0.66666D0,0.33333D0/
45 FQ=ALPEM/(2.*PI)*LOG(Q2/ALAM2)
48 POMG=0.194*(1.-DX)**1.03/(DX**0.97)
52 POM1=(1.81-1.67*DX+2.16*DX**2)
53 POM2=DX**0.7/(1.-0.4*LOG(1.-DX))
54 POM3=38.D-4*(1.-DX)**1.82/(DX**1.18)
55 DDB=(CQ(1)**2*POM1*POM2+POM3)*FQ
57 DUB=(CQ(2)**2*POM1*POM2+POM3)*FQ
59 DSB=(CQ(3)**2*POM1*POM2+POM3)*FQ
60 DCB=(CQ(4)**2*POM1*POM2+POM3)*FQ
61 DBB=(CQ(5)**2*POM1*POM2+POM3)*FQ