1 #include "isajet/pilot.h"
2 SUBROUTINE SSHGM1(TAU,IFFF,RFFF)
3 C-----------------------------------------------------------------------
5 C This subroutine uses the tau variable of the Higgs Hunters'
6 C Guide. Many other authors, including the paper cited in
7 C Higgs Hunters' Guide (PR. D. 38(11): 3481) and Collider Physics
8 C by Barger and Phillips use the variable lambda
9 C LAMBDA = ( MASS OF PARTICLE IN LOOP / MASS OF HIGGS )**2
11 C Note also that what is defined as the f function by different
12 C authors varies by a constant factor. For example,
13 C f(Barger and Phillips) = -2 * f(Higgs Hunters' Guide)
16 C-----------------------------------------------------------------------
17 #if defined(CERNLIB_IMPNONE)
20 DOUBLE PRECISION TAU,IFFF,RFFF,ETAP,ETAM,PI
26 RFFF=(DASIN(DSQRT(1.0/TAU)))**2
28 ELSE IF (TAU.LT.1.0) THEN
29 ETAP=1.0D0+SQRT(1.0D0-TAU)
30 ETAM=1.0D0-SQRT(1.0D0-TAU)
31 RFFF=-((DLOG(ETAP/ETAM))**2-PI**2)/4.0D0
32 IFFF=PI*DLOG(ETAP/ETAM)/2.0D0