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Commit | Line | Data |
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3820ca8e | 1 | |
2 | CDECK ID>, HWHEW3. | |
3 | ||
4 | *CMZ :- -27/03/92 19.48.55 by Mike Seymour | |
5 | ||
6 | *-- Author : Zoltan Kunszt, modified by Bryan Webber | |
7 | ||
8 | C----------------------------------------------------------------------- | |
9 | ||
10 | SUBROUTINE HWHEW3(N1,N2,N3,N4,N5,N6,AMPWW) | |
11 | ||
12 | C----------------------------------------------------------------------- | |
13 | ||
14 | C RECALL THAT N1,N3,N5 MUST BE OUTGOING FERMIONS, AND N2,N4,N6 MUST BE | |
15 | ||
16 | C OUTGOING ANTI-FERMIONS; 3,4 FOR W-, 5,6 FOR W+ | |
17 | ||
18 | C | |
19 | ||
20 | C EQ1 AND T31 ARE FOR OUTOING INITIAL QUARK | |
21 | ||
22 | C CHOOSE APPROPRIATE CASE ACCORDING TO NUPDN | |
23 | ||
24 | C NUPDN=1 FOR UUBAR COLLISIONS, NUPDN=2 FOR DDBAR COLLISIONS | |
25 | ||
26 | C NFINAL CHOOSES THE FINAL DECAYS, 1 FOR DOUBLE LEPTON, 2 FOR 1 FLAVOR | |
27 | ||
28 | C LEPTON+2FAMILIES OF QUARKS, 3 THE SAME, 4 FOR DOUBLE 2FAM3COLOR QUARKS | |
29 | ||
30 | C | |
31 | ||
32 | C NOTE: EXTERNAL FACTOR OF COLOR AVERAGE AND SPIN AVERAGE AND | |
33 | ||
34 | C COUPLING (E**8/4/9) MUST BE INCLUDED AS WELL AS COMPENSATION | |
35 | ||
36 | C FOR ON POLE APPROXIMATION AS DESIRED. | |
37 | ||
38 | C----------------------------------------------------------------------- | |
39 | ||
40 | INCLUDE 'HERWIG61.INC' | |
41 | ||
42 | COMPLEX HWHEW4,ZH,ZCH,ZD,ZAMP1,ZAMP2,ZAMP3,DWW,CWW,BWW,AWW,AWWM, | |
43 | ||
44 | & AWWP,AMPTEM,ZTWO,ZHALF | |
45 | ||
46 | DOUBLE PRECISION XW,ZMASS,T3,EQ1,RR,RL,ZM2,AMP2,RKW,COLFAC(4), | |
47 | ||
48 | & AMPWW(4) | |
49 | ||
50 | INTEGER I,N1,N2,N3,N4,N5,N6 | |
51 | ||
52 | EXTERNAL HWHEW4 | |
53 | ||
54 | COMMON/HWHEWQ/ZH(7,7),ZCH(7,7),ZD(7,7) | |
55 | ||
56 | EQUIVALENCE (XW,SWEIN),(ZMASS,RMASS(200)) | |
57 | ||
58 | DATA COLFAC/1.D0,3.D0,3.D0,9.D0/ | |
59 | ||
60 | DATA ZTWO,ZHALF/(2.0,0.0),(0.5,0.0)/ | |
61 | ||
62 | T3=-1.D0 | |
63 | ||
64 | EQ1=-1.D0 | |
65 | ||
66 | RR=-2.D0*EQ1*XW | |
67 | ||
68 | RL=T3+RR | |
69 | ||
70 | ZM2=ZMASS*ZMASS | |
71 | ||
72 | ZAMP1=CMPLX(ZM2)/(ZTWO*ZD(N1,N2)) | |
73 | ||
74 | & /(ZTWO*ZD(N1,N2)+CMPLX(-ZM2,GAMZ*ZMASS)) | |
75 | ||
76 | ZAMP2=ZHALF/(ZD(N1,N3)+ZD(N1,N4)+ZD(N3,N4)) | |
77 | ||
78 | ZAMP3=ZHALF/(ZD(N1,N5)+ZD(N1,N6)+ZD(N5,N6)) | |
79 | ||
80 | DWW=CMPLX(RL)*ZAMP1+T3/(ZTWO*ZD(N1,N2)) | |
81 | ||
82 | CWW=CMPLX(RR)*ZAMP1 | |
83 | ||
84 | AWW=DWW | |
85 | ||
86 | BWW=DWW-ZAMP3 | |
87 | ||
88 | AWWM=AWW*HWHEW4(N1,N2,N3,N4,N5,N6)-BWW*HWHEW4(N1,N2,N5,N6,N3,N4) | |
89 | ||
90 | AWWP=CWW*(HWHEW4(N2,N1,N5,N6,N3,N4)-HWHEW4(N2,N1,N3,N4,N5,N6)) | |
91 | ||
92 | AMPTEM=AWWM*CONJG(AWWM)+AWWP*CONJG(AWWP) | |
93 | ||
94 | AMP2=REAL(AMPTEM) | |
95 | ||
96 | C AMP2 DOES NOT INCLUDE COLOR OR FLAVOR SUMS OR AVERAGES YET | |
97 | ||
98 | C NOR DOES IT INCLUDE TO THIS POINT KWW**2 | |
99 | ||
100 | C 1 LEPTON FLAVOR IF APPROPRIATE FOR NFINAL CHOICE | |
101 | ||
102 | RKW=0.25D0/XW**2 | |
103 | ||
104 | DO 6 I=1,4 | |
105 | ||
106 | 6 AMPWW(I)=AMP2*COLFAC(I)*RKW*RKW | |
107 | ||
108 | RETURN | |
109 | ||
110 | END |