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0795afa3 | 1 | #include "isajet/pilot.h" |
2 | FUNCTION DECSS3(IP,MEA) | |
3 | C | |
4 | C Compute matrix element for mode MEA of particle IP using | |
5 | C poles and couplings in /DKYSS3/. | |
6 | C Auxiliary routine for DECAY. | |
7 | C | |
8 | #if defined(CERNLIB_IMPNONE) | |
9 | IMPLICIT NONE | |
10 | #endif | |
11 | C | |
12 | #include "isajet/itapes.inc" | |
13 | #include "isajet/partcl.inc" | |
14 | #include "isajet/const.inc" | |
15 | #include "isajet/dkyss3.inc" | |
16 | C | |
17 | LOGICAL KIN(4),KINP(4) | |
18 | INTEGER IP,MEA,I,J,JP,II,PTYPE1,PTYPE2 | |
19 | REAL DECSS3 | |
20 | REAL AM0SQ,AM1SQ,AM2SQ,AM3SQ,S12,S13,S23 | |
21 | REAL D12,D13,D23,D01,D02,D03,AS,BS,CS,DS,MSQ | |
22 | REAL DOT4 | |
23 | COMPLEX A,B,C,D,AC,BC,CC,DC,AP,BP,CP,DP,APC,BPC,CPC,DPC,MMPD | |
24 | C | |
25 | DOT4(I,J)=PPTCL(4,I)*PPTCL(4,J)-PPTCL(1,I)*PPTCL(1,J)- | |
26 | $PPTCL(2,I)*PPTCL(2,J)-PPTCL(3,I)*PPTCL(3,J) | |
27 | C | |
28 | C Kinematics | |
29 | C | |
30 | AM0SQ=PPTCL(5,IP)**2 | |
31 | AM1SQ=PPTCL(5,NPTCL+1)**2 | |
32 | AM2SQ=PPTCL(5,NPTCL+2)**2 | |
33 | AM3SQ=PPTCL(5,NPTCL+3)**2 | |
34 | D12=DOT4(NPTCL+1,NPTCL+2) | |
35 | D13=DOT4(NPTCL+1,NPTCL+3) | |
36 | D23=DOT4(NPTCL+2,NPTCL+3) | |
37 | D01=DOT4(IP,NPTCL+1) | |
38 | D02=DOT4(IP,NPTCL+2) | |
39 | D03=DOT4(IP,NPTCL+3) | |
40 | S12=2*D12+AM1SQ+AM2SQ | |
41 | S13=2*D13+AM1SQ+AM3SQ | |
42 | S23=2*D23+AM2SQ+AM3SQ | |
43 | C | |
44 | C Generic matrix element | |
45 | C | |
46 | C Loop over diagrams | |
47 | DECSS3=0. | |
48 | DO J=J1SS3(MEA),J2SS3(MEA) | |
49 | PTYPE1=KSS3(J) | |
50 | A=ZISS3(1,J) | |
51 | B=ZISS3(2,J) | |
52 | C=ZFSS3(1,J) | |
53 | D=ZFSS3(2,J) | |
54 | AC=CONJG(A) | |
55 | BC=CONJG(B) | |
56 | CC=CONJG(C) | |
57 | DC=CONJG(D) | |
58 | AS=A*AC | |
59 | BS=B*BC | |
60 | CS=C*CC | |
61 | DS=D*DC | |
62 | DO JP=J,J2SS3(MEA) | |
63 | MSQ=0. | |
64 | DO II=1,4 | |
65 | KIN(II)=.FALSE. | |
66 | KINP(II)=.FALSE. | |
67 | END DO | |
68 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+1)).LT.AMSS3(J)) KIN(1)=.TRUE. | |
69 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+3)).LT.AMSS3(J)) KIN(2)=.TRUE. | |
70 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+2)).LT.AMSS3(J)) KIN(3)=.TRUE. | |
71 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+1)).LT.AMSS3(J)) KIN(4)=.TRUE. | |
72 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+1)).LT.AMSS3(JP)) KINP(1)=.TRUE. | |
73 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+3)).LT.AMSS3(JP)) KINP(2)=.TRUE. | |
74 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+2)).LT.AMSS3(JP)) KINP(3)=.TRUE. | |
75 | IF ((PPTCL(5,IP)-PPTCL(5,NPTCL+1)).LT.AMSS3(JP)) KINP(4)=.TRUE. | |
76 | IF (J.EQ.JP) THEN | |
77 | IF (PTYPE1.EQ.1.AND.KIN(1)) THEN | |
78 | MSQ=32*(((AS+BS)*(CS+DS)+4*REAL(A*BC*C*DC))*D03*D12+ | |
79 | $ ((AS+BS)*(CS+DS)-4*REAL(A*BC*C*DC))*D02*D13+ | |
80 | $ (BS-AS)*(CS+DS)*SQRT(AM0SQ*AM1SQ)*D23)/ | |
81 | $ (S23-AMSS3(J)**2)**2 | |
82 | ELSE IF (PTYPE1.EQ.2.AND.KIN(2)) THEN | |
83 | MSQ=16*(AS+BS)*(CS+DS)*D03*D12/(S12-AMSS3(J)**2)**2 | |
84 | ELSE IF (PTYPE1.EQ.3.AND.KIN(3)) THEN | |
85 | MSQ=16*(AS+BS)*(CS+DS)*D02*D13/(S13-AMSS3(J)**2)**2 | |
86 | ELSE IF (PTYPE1.EQ.4.AND.KIN(4)) THEN | |
87 | MSQ=16*((AS+BS)*(CS+DS)*D01*D23+(AS-BS)*(CS+DS)*D23* | |
88 | $ SQRT(AM0SQ*AM1SQ))/(S23-AMSS3(J)**2)**2 | |
89 | END IF | |
90 | END IF | |
91 | IF (J.NE.JP) THEN | |
92 | PTYPE2=KSS3(JP) | |
93 | AP=ZISS3(1,JP) | |
94 | BP=ZISS3(2,JP) | |
95 | CP=ZFSS3(1,JP) | |
96 | DP=ZFSS3(2,JP) | |
97 | APC=CONJG(AP) | |
98 | BPC=CONJG(BP) | |
99 | CPC=CONJG(CP) | |
100 | DPC=CONJG(DP) | |
101 | IF (PTYPE1.EQ.2.AND.PTYPE2.EQ.2.AND.KIN(2).AND.KINP(2)) THEN | |
102 | MMPD=16*D12*D03*(A*APC+B*BPC)*(C*CPC+D*DPC)/ | |
103 | $ (S12-AMSS3(J)**2)/(S12-AMSS3(JP)**2) | |
104 | MSQ=2*REAL(MMPD) | |
105 | END IF | |
106 | IF (PTYPE1.EQ.3.AND.PTYPE2.EQ.3.AND.KIN(3).AND.KINP(3)) THEN | |
107 | MMPD=16*D13*D02*(A*APC+B*BPC)*(C*CPC+D*DPC)/ | |
108 | $ (S13-AMSS3(J)**2)/(S13-AMSS3(JP)**2) | |
109 | MSQ=2*REAL(MMPD) | |
110 | END IF | |
111 | IF (PTYPE1.EQ.4.AND.PTYPE2.EQ.4.AND.KIN(4).AND.KINP(4)) THEN | |
112 | MMPD=16*D23*(D01*(A*APC+B*BPC)*(C*CPC+D*DPC)+ | |
113 | $ SQRT(AM0SQ*AM1SQ)*(A*APC-B*BPC)*(C*CPC-D*DPC))/ | |
114 | $ (S23-AMSS3(J)**2)/(S23-AMSS3(JP)**2) | |
115 | MSQ=2*REAL(MMPD) | |
116 | END IF | |
117 | IF (PTYPE1.EQ.1.AND.PTYPE2.EQ.3.AND.KIN(1).AND.KINP(3)) THEN | |
118 | MMPD=(16*D13*D02*((A*C-B*D)*(-APC*CPC+BPC*DPC)+ | |
119 | $ (A*D-B*C)*(APC*DPC-BPC*CPC))+ | |
120 | $ 8*D23*SQRT(AM0SQ*AM1SQ)*((A*C+B*D)*(APC*CPC-BPC*DPC)- | |
121 | $ (A*D+B*C)*(APC*DPC-BPC*CPC)))/ | |
122 | $ (S23-AMSS3(J)**2)/(S13-AMSS3(JP)**2) | |
123 | MSQ=2*REAL(MMPD) | |
124 | END IF | |
125 | IF (PTYPE1.EQ.1.AND.PTYPE2.EQ.2.AND.KIN(1).AND.KINP(2)) THEN | |
126 | MMPD=(16*D12*D03*((A*C+B*D)*(-APC*CPC+BPC*DPC)+ | |
127 | $ (A*D+B*C)*(APC*DPC-BPC*CPC))+ | |
128 | $ 8*D23*SQRT(AM0SQ*AM1SQ)*((A*C-B*D)*(APC*CPC-BPC*DPC)+ | |
129 | $ (-A*D+B*C)*(APC*DPC+BPC*CPC)))/ | |
130 | $ (S23-AMSS3(J)**2)/(S12-AMSS3(JP)**2) | |
131 | MSQ=2*REAL(MMPD) | |
132 | END IF | |
133 | IF (PTYPE1.EQ.3.AND.PTYPE2.EQ.4.AND.KIN(3).AND.KINP(4)) THEN | |
134 | MMPD=((8*D13*D23+4*D23*AM1SQ)*((A*C+B*D)*(APC*CPC+BPC*DPC)+ | |
135 | $ (A*D+B*C)*(APC*DPC+BPC*CPC))+ | |
136 | $ 4*D23*SQRT(AM0SQ*AM1SQ)*((A*C+B*D)*(APC*CPC-BPC*DPC)+ | |
137 | $ (A*D+B*C)*(APC*DPC-BPC*CPC)))/ | |
138 | $ (S13-AMSS3(J)**2)/(S23-AMSS3(JP)**2) | |
139 | MSQ=2*REAL(MMPD) | |
140 | END IF | |
141 | IF (PTYPE1.EQ.2.AND.PTYPE2.EQ.4.AND.KIN(2).AND.KINP(4)) THEN | |
142 | MMPD=-((8*D12*D23+4*D23*AM1SQ)*((A*C+B*D)*(APC*CPC+BPC*DPC)+ | |
143 | $ (A*D+B*C)*(APC*DPC+BPC*CPC))+ | |
144 | $ 4*D23*SQRT(AM0SQ*AM1SQ)*((A*C+B*D)*(APC*CPC-BPC*DPC)+ | |
145 | $ (A*D+B*C)*(APC*DPC-BPC*CPC)))/ | |
146 | $ (S12-AMSS3(J)**2)/(S23-AMSS3(JP)**2) | |
147 | MSQ=2*REAL(MMPD) | |
148 | END IF | |
149 | IF (PTYPE1.EQ.2.AND.PTYPE2.EQ.3.AND.KIN(2).AND.KINP(3)) THEN | |
150 | MMPD=((8*D12*D13-4*D23*AM1SQ)*((A*C+B*D)*(APC*CPC+BPC*DPC)+ | |
151 | $ (A*D+B*C)*(APC*DPC+BPC*CPC))- | |
152 | $ 4*D23*SQRT(AM0SQ*AM1SQ)*((A*C-B*D)*(APC*CPC-BPC*DPC)+ | |
153 | $ (A*D-B*C)*(APC*DPC-BPC*CPC)))/ | |
154 | $ (S12-AMSS3(J)**2)/(S13-AMSS3(JP)**2) | |
155 | MSQ=2*REAL(MMPD) | |
156 | END IF | |
157 | END IF | |
158 | DECSS3=DECSS3+MSQ | |
159 | END DO | |
160 | END DO | |
161 | C | |
162 | RETURN | |
163 | END |