* * $Id$ * * $Log$ * Revision 1.1.1.2 1996/10/30 08:32:35 cernlib * Version 7.04 * * Revision 1.2 1996/10/28 15:02:12 pdflib * PDFLIB new version 7.04 * * Revision 1.1.1.1 1996/04/12 15:29:23 plothow * Version 7.01 * * #include "pdf/pilot.h" SUBROUTINE GRVGAH0 (ZX,ZQ,ZUV,ZDV,ZUB,ZDB,ZSB,ZCB,ZBB,ZGL) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * G R V - P H O T O N - P A R A M E T R I Z A T I O N S * * * * FOR A DETAILED EXPLANATION SEE : * * M. GLUECK, E.REYA, A.VOGT: DO-TH 91/31 * * * * THE OUTPUT IS ALWAYS 1./ ALPHA(EM) * X * PARTON DENSITY * * output modified by HPB to be always X * PARTON DENSITY * * * * THE PARAMETRIZATIONS ARE FITTED TO THE PARTON DISTRIBUTIONS * * FOR Q ** 2 BETWEEN MU ** 2 (= 0.25 / 0.30 GEV ** 2 IN LO * * / HO) AND 1.E6 GEV ** 2 AND FOR X BETWEEN 1.E-5 AND 1. * * * * HEAVY QUARK THRESHOLDS Q(H) = M(H) : * * M(C) = 1.5, M(B) = 4.5, M(T) = 100 GEV * * * * CORRESPONDING LAMBDA(F) VALUES FOR F ACTIVE FLAVOURS : * * LO : LAMBDA(3) = 0.232, LAMBDA(4) = 0.200, * * LAMBDA(5) = 0.153, LAMBDA(6) = 0.082 GEV * * HO : LAMBDA(3) = 0.248, LAMBDA(4) = 0.200, * * LAMBDA(5) = 0.131, LAMBDA(6) = 0.053 GEV * * * * HO DISTRIBUTIONS REFER TO THE DIS(GAMMA) SCHEME, SEE : * * M. GLUECK, E.REYA, A.VOGT: DO-TH 91/26 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * C IMPLICIT REAL (A - Y) #include "pdf/expdp.inc" + ZX,ZQ,ZUV,ZDV,ZUB,ZDB,ZSB,ZCB,ZBB,ZGL REAL X, Q DATA ALPHEM/7.29927D-3/ X = ZX Q = ZQ MU2 = 0.3 LAM2 = 0.248 * 0.248 Q2 = Q*Q S = ALOG (ALOG(Q2/LAM2) / ALOG(MU2/LAM2)) SS = SQRT (S) S2 = S * S C...X * U = X * UBAR : AL = 1.447 BE = 0.848 AK = 0.527 + 0.200 * S - 0.107 * S2 BK = 7.106 - 0.310 * SS - 0.786 * S2 AG = 0.197 + 0.533 * S BG = 0.062 - 0.398 * S + 0.109 * S2 C = 0.755 * S - 0.112 * S2 D = 0.318 - 0.059 * S E = 4.225 + 1.708 * S ES = 1.752 + 0.866 * S U0 = GRVGF (X, S, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZUV = U0 * ALPHEM ZUB = ZUV C...X * D = X * DBAR : AL = 1.424 BE = 0.770 AK = 0.500 + 0.067 * SS - 0.055 * S2 BK = 0.376 - 0.453 * SS + 0.405 * S2 AG = 0.156 + 0.184 * S BG = 0.0 - 0.528 * S + 0.146 * S2 C = 0.121 + 0.092 * S D = 0.379 - 0.301 * S + 0.081 * S2 E = 4.346 + 1.638 * S ES = 1.645 + 1.016 * S D0 = GRVGF (X, S, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZDV = D0 * ALPHEM ZDB = ZDV C...X * G : AL = 0.661 BE = 0.793 AK = 0.537 - 0.600 * SS BK = 6.389 - 0.953 * S2 AG = 0.558 - 0.383 * SS + 0.261 * S2 BG = 0.0 - 0.305 * S C = -0.222 + 0.078 * S2 D = 0.153 + 0.978 * S - 0.209 * S2 E = 1.429 + 1.772 * S ES = 3.331 + 0.806 * S G0 = GRVGF (X, S, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZGL = G0 * ALPHEM C...X * S = X * SBAR : SF = 0.0 AL = 1.578 BE = 0.863 AK = 0.622 + 0.332 * S - 0.300 * S2 BK = 2.469 AG = 0.211 - 0.064 * SS - 0.018 * S2 BG = -0.215 + 0.122 * S C = 0.153 D = 0.0 + 0.253 * S - 0.081 * S2 E = 3.990 + 2.014 * S ES = 1.720 + 0.986 * S S0 = GRVGFS (X, S, SF, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZSB = S0 * ALPHEM C...X * C = X * CBAR : SF = 0.820 AL = 0.929 BE = 0.381 AK = 1.228 - 0.231 * S BK = 3.806 - 0.337 * S2 AG = 0.932 + 0.150 * S BG = -0.906 C = 1.133 D = 0.0 + 0.138 * S - 0.028 * S2 E = 5.588 + 0.628 * S ES = 2.665 + 1.054 * S C0 = GRVGFS (X, S, SF, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZCB = C0 * ALPHEM C...X * B = X * BBAR : SF = 1.297 AL = 0.970 BE = 0.207 AK = 1.719 - 0.292 * S BK = 0.928 + 0.096 * S AG = 0.845 + 0.178 * S BG = -2.310 C = 1.558 D = -0.191 + 0.151 * S E = 6.089 + 0.282 * S ES = 3.379 + 1.062 * S B0 = GRVGFS (X, S, SF, AL, BE, AK, BK, AG, BG, C, D, E, ES) ZBB = B0 * ALPHEM C RETURN END