3 C***********************************************************************
5 FUNCTION PYW1AU_HIJING(EPS,IREIM)
7 C...Calculates real and imaginary parts of the auxiliary function W1;
8 C...see R. K. Ellis, I. Hinchliffe, M. Soldate and J. J. van der Bij,
9 C...FERMILAB-Pub-87/100-T, LBL-23504, June, 1987
10 #include "ludat1_hijing.inc"
12 ASINH(X)=LOG(X+SQRT(X**2+1.))
13 ACOSH(X)=LOG(X+SQRT(X**2-1.))
16 W1RE=2.*SQRT(1.-EPS)*ASINH(SQRT(-1./EPS))
18 ELSEIF(EPS.LT.1.) THEN
19 W1RE=2.*SQRT(1.-EPS)*ACOSH(SQRT(1./EPS))
20 W1IM=-PARU(1)*SQRT(1.-EPS)
22 W1RE=2.*SQRT(EPS-1.)*ASIN(SQRT(1./EPS))
26 IF(IREIM.EQ.1) PYW1AU_HIJING=W1RE
27 IF(IREIM.EQ.2) PYW1AU_HIJING=W1IM