[u/mrichter/AliRoot.git] / PDF / spdf / rxud.F

*
* $Id$
*
* $Log$
* Revision 1.4  2000/09/18 10:02:36  hristov
* Makefile added to PDF8
*
* Revision 1.1.1.2  1996/10/30 08:29:18  cernlib
* Version 7.04
*
* Revision 1.1.1.1  1996/04/12 15:29:29  plothow
* Version 7.01
*
*
#include "pdf/pilot.h"
      SUBROUTINE RXUD (X,QQ,XUD)
C.......................................................................
C.
C.    F3   (GIVES VALENCE FOR U AND D)
C.
C.......................................................................
#include "pdf/impdp.inc"
#if defined(CERNLIB_DOUBLE)
      DOUBLE PRECISION
#endif
#if defined(CERNLIB_SINGLE)
      REAL
#endif
     +       BBETA
      DATA XLAM /0.50D00/, Q0/2.1D0/, Q00/1.8D0/
      DATA ONED/1.D0/, THRED/3.D0/
      IF(QQ.LT.Q0) QQ=Q0
      S=LOG(QQ/XLAM**2)/LOG(Q00/XLAM**2)
      S=LOG(S)
      ETA1=0.7D00-0.176D00*S
      ETA2=2.6D00+0.8D00*S
      XUD=THRED*(X**ETA1)*((ONED-X)**ETA2)/BBETA(ETA1,ONED+ETA2)
      RETURN
      END
Commit	Line	Data
21886bb6	1	*
	2	* $Id$
	3	*
	4	* $Log$
7ef50f50	5	* Revision 1.4 2000/09/18 10:02:36 hristov
	6	* Makefile added to PDF8
	7	*
21886bb6	8	* Revision 1.1.1.2 1996/10/30 08:29:18 cernlib
	9	* Version 7.04
	10	*
	11	* Revision 1.1.1.1 1996/04/12 15:29:29 plothow
	12	* Version 7.01
	13	*
	14	*
	15	#include "pdf/pilot.h"
	16	SUBROUTINE RXUD (X,QQ,XUD)
	17	C.......................................................................
	18	C.
	19	C. F3 (GIVES VALENCE FOR U AND D)
	20	C.
	21	C.......................................................................
	22	#include "pdf/impdp.inc"
7ef50f50	23	#if defined(CERNLIB_DOUBLE)
	24	DOUBLE PRECISION
	25	#endif
	26	#if defined(CERNLIB_SINGLE)
	27	REAL
	28	#endif
21886bb6	29	+ BBETA
	30	DATA XLAM /0.50D00/, Q0/2.1D0/, Q00/1.8D0/
	31	DATA ONED/1.D0/, THRED/3.D0/
	32	IF(QQ.LT.Q0) QQ=Q0
	33	S=LOG(QQ/XLAM2)/LOG(Q00/XLAM2)
	34	S=LOG(S)
	35	ETA1=0.7D00-0.176D00*S
	36	ETA2=2.6D00+0.8D00*S
	37	XUD=THRED(XETA1)((ONED-X)**ETA2)/BBETA(ETA1,ONED+ETA2)
	38	RETURN
	39	END