4 *CMZ :- -05/11/95 19.33.42 by Mike Seymour
6 *-- Author : Adapted by Bryan Webber
8 C-----------------------------------------------------------------------
10 SUBROUTINE HWULF4(PS,PI,PF)
12 C-----------------------------------------------------------------------
14 C TRANSFORMS PI (GIVEN IN LAB) INTO PF (IN REST FRAME OF PS)
16 C N.B. P(1,2,3,4) = (PX,PY,PZ,E); PS(5)=M
18 C-----------------------------------------------------------------------
20 DOUBLE PRECISION PF4,FN,PS(5),PI(4),PF(4)
22 IF (PS(4).EQ.PS(5)) THEN
34 PF4 = (PI(4)*PS(4)-PI(3)*PS(3)
36 & -PI(2)*PS(2)-PI(1)*PS(1))/PS(5)
38 FN = (PF4+PI(4)) / (PS(4)+PS(5))
40 PF(1)= PI(1) - FN*PS(1)
42 PF(2)= PI(2) - FN*PS(2)
44 PF(3)= PI(3) - FN*PS(3)