4 *CMZ :- -27/03/92 19.48.55 by Mike Seymour
6 *-- Author : Zoltan Kunszt, modified by Bryan Webber
8 C-----------------------------------------------------------------------
10 SUBROUTINE HWHEW3(N1,N2,N3,N4,N5,N6,AMPWW)
12 C-----------------------------------------------------------------------
14 C RECALL THAT N1,N3,N5 MUST BE OUTGOING FERMIONS, AND N2,N4,N6 MUST BE
16 C OUTGOING ANTI-FERMIONS; 3,4 FOR W-, 5,6 FOR W+
20 C EQ1 AND T31 ARE FOR OUTOING INITIAL QUARK
22 C CHOOSE APPROPRIATE CASE ACCORDING TO NUPDN
24 C NUPDN=1 FOR UUBAR COLLISIONS, NUPDN=2 FOR DDBAR COLLISIONS
26 C NFINAL CHOOSES THE FINAL DECAYS, 1 FOR DOUBLE LEPTON, 2 FOR 1 FLAVOR
28 C LEPTON+2FAMILIES OF QUARKS, 3 THE SAME, 4 FOR DOUBLE 2FAM3COLOR QUARKS
32 C NOTE: EXTERNAL FACTOR OF COLOR AVERAGE AND SPIN AVERAGE AND
34 C COUPLING (E**8/4/9) MUST BE INCLUDED AS WELL AS COMPENSATION
36 C FOR ON POLE APPROXIMATION AS DESIRED.
38 C-----------------------------------------------------------------------
40 INCLUDE 'HERWIG61.INC'
42 COMPLEX HWHEW4,ZH,ZCH,ZD,ZAMP1,ZAMP2,ZAMP3,DWW,CWW,BWW,AWW,AWWM,
44 & AWWP,AMPTEM,ZTWO,ZHALF
46 DOUBLE PRECISION XW,ZMASS,T3,EQ1,RR,RL,ZM2,AMP2,RKW,COLFAC(4),
50 INTEGER I,N1,N2,N3,N4,N5,N6
54 COMMON/HWHEWQ/ZH(7,7),ZCH(7,7),ZD(7,7)
56 EQUIVALENCE (XW,SWEIN),(ZMASS,RMASS(200))
58 DATA COLFAC/1.D0,3.D0,3.D0,9.D0/
60 DATA ZTWO,ZHALF/(2.0,0.0),(0.5,0.0)/
72 ZAMP1=CMPLX(ZM2)/(ZTWO*ZD(N1,N2))
74 & /(ZTWO*ZD(N1,N2)+CMPLX(-ZM2,GAMZ*ZMASS))
76 ZAMP2=ZHALF/(ZD(N1,N3)+ZD(N1,N4)+ZD(N3,N4))
78 ZAMP3=ZHALF/(ZD(N1,N5)+ZD(N1,N6)+ZD(N5,N6))
80 DWW=CMPLX(RL)*ZAMP1+T3/(ZTWO*ZD(N1,N2))
88 AWWM=AWW*HWHEW4(N1,N2,N3,N4,N5,N6)-BWW*HWHEW4(N1,N2,N5,N6,N3,N4)
90 AWWP=CWW*(HWHEW4(N2,N1,N5,N6,N3,N4)-HWHEW4(N2,N1,N3,N4,N5,N6))
92 AMPTEM=AWWM*CONJG(AWWM)+AWWP*CONJG(AWWP)
96 C AMP2 DOES NOT INCLUDE COLOR OR FLAVOR SUMS OR AVERAGES YET
98 C NOR DOES IT INCLUDE TO THIS POINT KWW**2
100 C 1 LEPTON FLAVOR IF APPROPRIATE FOR NFINAL CHOICE
106 6 AMPWW(I)=AMP2*COLFAC(I)*RKW*RKW