5 * Revision 1.4 2000/09/18 10:02:36 hristov
6 * Makefile added to PDF8
8 * Revision 1.1.1.2 1996/10/30 08:29:18 cernlib
11 * Revision 1.1.1.1 1996/04/12 15:29:29 plothow
15 #include "pdf/pilot.h"
16 SUBROUTINE RXUD (X,QQ,XUD)
17 C.......................................................................
19 C. F3 (GIVES VALENCE FOR U AND D)
21 C.......................................................................
22 #include "pdf/impdp.inc"
23 #if defined(CERNLIB_DOUBLE)
26 #if defined(CERNLIB_SINGLE)
30 DATA XLAM /0.50D00/, Q0/2.1D0/, Q00/1.8D0/
31 DATA ONED/1.D0/, THRED/3.D0/
33 S=LOG(QQ/XLAM**2)/LOG(Q00/XLAM**2)
35 ETA1=0.7D00-0.176D00*S
37 XUD=THRED*(X**ETA1)*((ONED-X)**ETA2)/BBETA(ETA1,ONED+ETA2)