3 C***********************************************************************
5 FUNCTION PYW2AU_HIJING(EPS,IREIM)
7 C...Calculates real and imaginary parts of the auxiliary function W2;
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 W2RE=4.*(ASINH(SQRT(-1./EPS)))**2
18 ELSEIF(EPS.LT.1.) THEN
19 W2RE=4.*(ACOSH(SQRT(1./EPS)))**2-PARU(1)**2
20 W2IM=-4.*PARU(1)*ACOSH(SQRT(1./EPS))
22 W2RE=-4.*(ASIN(SQRT(1./EPS)))**2
26 IF(IREIM.EQ.1) PYW2AU_HIJING=W2RE
27 IF(IREIM.EQ.2) PYW2AU_HIJING=W2IM