[u/mrichter/AliRoot.git] / HIJING / hijing1_36 / ghvq.F

* $Id$
C
C
C
	FUNCTION GHVQ(Y1,Y2,AMT2)
	IMPLICIT REAL*8 (A-H,O-Z)
#include "hiparnt.inc"
	DIMENSION F(2,7)
	SAVE
	XT=2.0*DSQRT(AMT2)/HINT1(1)
	X1=0.50*XT*(DEXP(Y1)+DEXP(Y2))
	X2=0.50*XT*(DEXP(-Y1)+DEXP(-Y2))
	SS=X1*X2*HINT1(1)**2
	AF=4.0
	IF(IHPR2(18).NE.0) AF=5.0
	DLAM=HIPR1(15)
	APH=12.0*3.1415926/(33.0-2.0*AF)/DLOG(AMT2/DLAM**2)
C
	CALL PARTON(F,X1,X2,AMT2)
C
	Gqq=4.0*(COSH(Y1-Y2)+HIPR1(7)**2/AMT2)/(1.D0+COSH(Y1-Y2))/9.0
     &      *(F(1,1)*F(2,2)+F(1,2)*F(2,1)+F(1,3)*F(2,4)
     &        +F(1,4)*F(2,3)+F(1,5)*F(2,6)+F(1,6)*F(2,5))
	Ggg=(8.D0*COSH(Y1-Y2)-1.D0)*(COSH(Y1-Y2)+2.0*HIPR1(7)**2/AMT2
     &      -2.0*HIPR1(7)**4/AMT2**2)/(1.0+COSH(Y1-Y2))/24.D0
     &      *F(1,7)*F(2,7)
C
	GHVQ=(Gqq+Ggg)*HIPR1(23)*3.14159*APH**2/SS**2
	RETURN
	END
Commit	Line	Data
e74335a4	1	* $Id$
	2	C
	3	C
	4	C
	5	FUNCTION GHVQ(Y1,Y2,AMT2)
	6	IMPLICIT REAL*8 (A-H,O-Z)
	7	#include "hiparnt.inc"
	8	DIMENSION F(2,7)
	9	SAVE
	10	XT=2.0*DSQRT(AMT2)/HINT1(1)
	11	X1=0.50XT(DEXP(Y1)+DEXP(Y2))
	12	X2=0.50XT(DEXP(-Y1)+DEXP(-Y2))
	13	SS=X1X2HINT1(1)**2
	14	AF=4.0
	15	IF(IHPR2(18).NE.0) AF=5.0
	16	DLAM=HIPR1(15)
	17	APH=12.03.1415926/(33.0-2.0AF)/DLOG(AMT2/DLAM**2)
	18	C
	19	CALL PARTON(F,X1,X2,AMT2)
	20	C
	21	Gqq=4.0(COSH(Y1-Y2)+HIPR1(7)*2/AMT2)/(1.D0+COSH(Y1-Y2))/9.0
	22	& (F(1,1)F(2,2)+F(1,2)F(2,1)+F(1,3)F(2,4)
	23	& +F(1,4)F(2,3)+F(1,5)F(2,6)+F(1,6)*F(2,5))
	24	Ggg=(8.D0COSH(Y1-Y2)-1.D0)(COSH(Y1-Y2)+2.0HIPR1(7)*2/AMT2
	25	& -2.0HIPR1(7)4/AMT2*2)/(1.0+COSH(Y1-Y2))/24.D0
	26	& F(1,7)F(2,7)
	27	C
	28	GHVQ=(Gqq+Ggg)HIPR1(23)3.14159APH2/SS*2
	29	RETURN
	30	END