Merging the VirtualMC branch to the main development branch (HEAD)
[u/mrichter/AliRoot.git] / HIJING / hipyset1_35 / pyw1au_hijing.F
... / ...
CommitLineData
1* $Id$
2
3C***********************************************************************
4
5 FUNCTION PYW1AU_HIJING(EPS,IREIM)
6
7C...Calculates real and imaginary parts of the auxiliary function W1;
8C...see R. K. Ellis, I. Hinchliffe, M. Soldate and J. J. van der Bij,
9C...FERMILAB-Pub-87/100-T, LBL-23504, June, 1987
10#include "ludat1_hijing.inc"
11
12 ASINH(X)=LOG(X+SQRT(X**2+1.))
13 ACOSH(X)=LOG(X+SQRT(X**2-1.))
14
15 IF(EPS.LT.0.) THEN
16 W1RE=2.*SQRT(1.-EPS)*ASINH(SQRT(-1./EPS))
17 W1IM=0.
18 ELSEIF(EPS.LT.1.) THEN
19 W1RE=2.*SQRT(1.-EPS)*ACOSH(SQRT(1./EPS))
20 W1IM=-PARU(1)*SQRT(1.-EPS)
21 ELSE
22 W1RE=2.*SQRT(EPS-1.)*ASIN(SQRT(1./EPS))
23 W1IM=0.
24 ENDIF
25
26 IF(IREIM.EQ.1) PYW1AU_HIJING=W1RE
27 IF(IREIM.EQ.2) PYW1AU_HIJING=W1IM
28
29 RETURN
30 END