More volume overlaps corrected
[u/mrichter/AliRoot.git] / ISAJET / code / zjj2.F
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0795afa3 1#include "isajet/pilot.h"
2 REAL*8 FUNCTION ZJJ2(P1, P2, P3, P4, P5,NHEL,IM)
3C
4C Function generated by Madgraph + hand coding
5C Returns amplitude squared summed/ave over colors
6C for the point in phase space P1,P2,P3,P4,P5
7C and helicity NHEL(1)...
8C for the process: g g -> z q(im) qb(im)
9C with Madgraph code IM
10C
11#if defined(CERNLIB_IMPNONE)
12 IMPLICIT NONE
13#endif
14C
15C CONSTANTS
16C
17 INTEGER NGRAPHS, NEIGEN, NEXTERNAL
18 PARAMETER (NGRAPHS= 8,NEIGEN= 2,NEXTERNAL=5)
19 REAL*8 ZERO
20 PARAMETER (ZERO=0D0)
21C
22C ARGUMENTS
23C
24 REAL*8 P1(0:3),P2(0:3),P3(0:3),P4(0:3),P5(0:3)
25 INTEGER NHEL(NEXTERNAL)
26 INTEGER IM
27C
28C LOCAL VARIABLES
29C
30 INTEGER I,J
31 REAL*8 EIGEN_VAL(NEIGEN), EIGEN_VEC(NGRAPHS,NEIGEN)
32 COMPLEX*16 ZTEMP
33 COMPLEX*16 AMP(NGRAPHS)
34 COMPLEX*16 W1(6) , W2(6) , W3(6) , W4(6) , W5(6)
35 COMPLEX*16 W6(6) , W7(6) , W8(6) , W9(6) , W10(6)
36 COMPLEX*16 W11(6) , W12(6) , W13(6)
37 REAL*8 GZUD(2)
38C
39C GLOBAL VARIABLES
40C
41#include "isajet/mgcoms.inc"
42C
43C COLOR DATA
44C
45 DATA EIGEN_VAL(1 )/ 2.1875000000000006D-01 /
46 DATA EIGEN_VEC(1 ,1 )/ -4.0824829046386291D-01 /
47 DATA EIGEN_VEC(2 ,1 )/ -4.0824829046386291D-01 /
48 DATA EIGEN_VEC(3 ,1 )/ -4.0824829046386307D-01 /
49 DATA EIGEN_VEC(4 ,1 )/ -4.0824829046386307D-01 /
50 DATA EIGEN_VEC(5 ,1 )/ -4.0824829046386307D-01 /
51 DATA EIGEN_VEC(6 ,1 )/ -4.0824829046386291D-01 /
52 DATA EIGEN_VEC(7 ,1 )/ 0.0000000000000000D+00 /
53 DATA EIGEN_VEC(8 ,1 )/ 0.0000000000000000D+00 /
54 DATA EIGEN_VAL(2 )/ 6.5624999999999967D-01 /
55 DATA EIGEN_VEC(1 ,2 )/ -2.6726124191242451D-01 /
56 DATA EIGEN_VEC(2 ,2 )/ -2.6726124191242451D-01 /
57 DATA EIGEN_VEC(3 ,2 )/ 2.6726124191242440D-01 /
58 DATA EIGEN_VEC(4 ,2 )/ 2.6726124191242440D-01 /
59 DATA EIGEN_VEC(5 ,2 )/ 2.6726124191242440D-01 /
60 DATA EIGEN_VEC(6 ,2 )/ -2.6726124191242451D-01 /
61 DATA EIGEN_VEC(7 ,2 )/ -5.3452248382484857D-01 /
62 DATA EIGEN_VEC(8 ,2 )/ -5.3452248382484857D-01 /
63C ----------
64C BEGIN CODE
65C ----------
66 IF(IM.EQ.4.OR.IM.EQ.8.OR.IM.EQ.12) THEN
67 GZUD(1)=GZD(1)
68 GZUD(2)=GZD(2)
69 ELSE
70 GZUD(1)=GZU(1)
71 GZUD(2)=GZU(2)
72 ENDIF
73C
74 CALL VXXXXX(P1 , ZERO,NHEL(1 ),-1,W1 )
75 CALL VXXXXX(P2 , ZERO,NHEL(2 ),-1,W2 )
76 CALL VXXXXX(P3 ,ZMASS,NHEL(3 ), 1,W3 )
77 CALL OXXXXX(P4 ,FMASS(IM),NHEL(4 ), 1,W4 )
78 CALL IXXXXX(P5 ,FMASS(IM),NHEL(5 ),-1,W5 )
79 CALL FVOXXX(W4 ,W1 ,GG,FMASS(IM),FWIDTH(IM),W6 )
80 CALL FVIXXX(W5 ,W2 ,GG,FMASS(IM),FWIDTH(IM),W7 )
81 CALL IOVXXX(W7 ,W6 ,W3 ,GZUD,AMP(1 ))
82 CALL FVIXXX(W5 ,W3 ,GZUD,FMASS(IM),FWIDTH(IM),W8 )
83 CALL IOVXXX(W8 ,W6 ,W2 ,GG,AMP(2 ))
84 CALL FVOXXX(W4 ,W2 ,GG,FMASS(IM),FWIDTH(IM),W9 )
85 CALL FVIXXX(W5 ,W1 ,GG,FMASS(IM),FWIDTH(IM),W10 )
86 CALL IOVXXX(W10 ,W9 ,W3 ,GZUD,AMP(3 ))
87 CALL IOVXXX(W8 ,W9 ,W1 ,GG,AMP(4 ))
88 CALL FVOXXX(W4 ,W3 ,GZUD,FMASS(IM),FWIDTH(IM),W11 )
89 CALL IOVXXX(W10 ,W11 ,W2 ,GG,AMP(5 ))
90 CALL IOVXXX(W7 ,W11 ,W1 ,GG,AMP(6 ))
91 CALL JGGXXX(W1 ,W2 ,G,W12 )
92 CALL FVOXXX(W4 ,W12 ,GG,FMASS(IM),FWIDTH(IM),W13 )
93 CALL IOVXXX(W5 ,W13 ,W3 ,GZUD,AMP(7 ))
94 CALL IOVXXX(W5 ,W11 ,W12 ,GG,AMP(8 ))
95 ZJJ2 = 0.D0
96 DO I = 1, NEIGEN
97 ZTEMP = (0.D0,0.D0)
98 DO J = 1, NGRAPHS
99 ZTEMP = ZTEMP + EIGEN_VEC(J,I)*AMP(J)
100 ENDDO
101 ZJJ2 =ZJJ2+ZTEMP*EIGEN_VAL(I)*CONJG(ZTEMP)
102 ENDDO
103C CALL GAUGECHECK(AMP,ZTEMP,EIGEN_VEC,EIGEN_VAL,NGRAPHS,NEIGEN)
104 END