4 *CMZ :- -26/04/91 11.11.56 by Bryan Webber
6 *-- Author : Bryan Webber
8 C-----------------------------------------------------------------------
12 C-----------------------------------------------------------------------
14 C LONGITUDINAL RAPIDITY (SET TO +/-1000 IF TOO LARGE)
16 C-----------------------------------------------------------------------
18 DOUBLE PRECISION HWURAP,EMT2,P(5),ZERO
22 EMT2=P(1)**2+P(2)**2+P(5)**2
24 IF (P(3).GT.ZERO) THEN
26 IF (EMT2.EQ.ZERO) THEN
32 HWURAP= 0.5*LOG((P(3)+P(4))**2/EMT2)
36 ELSEIF (P(3).LT.ZERO) THEN
38 IF (EMT2.EQ.ZERO) THEN
44 HWURAP=-0.5*LOG((P(3)-P(4))**2/EMT2)