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Commit | Line | Data |
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0795afa3 | 1 | #include "isajet/pilot.h" |
2 | REAL FUNCTION SSGT(S,AMSQ,Z,I,J) | |
3 | C----------------------------------------------------------------------- | |
4 | C Function for Sig(qqbar->z_i + z_j | |
5 | C----------------------------------------------------------------------- | |
6 | #if defined(CERNLIB_IMPNONE) | |
7 | IMPLICIT NONE | |
8 | #endif | |
9 | #include "isajet/sssm.inc" | |
10 | #include "isajet/sspar.inc" | |
11 | REAL S,AMSQ,K,Z,MZI,MZJ,RS,TPP,TPM,BTP,BTM | |
12 | INTEGER I,J,ITHI,ITHJ | |
13 | C | |
14 | MZI=ABS(AMZISS(I)) | |
15 | MZJ=ABS(AMZISS(J)) | |
16 | IF (AMZISS(I).LT.0.) THEN | |
17 | ITHI=1 | |
18 | ELSE | |
19 | ITHI=0 | |
20 | END IF | |
21 | IF (AMZISS(J).LT.0.) THEN | |
22 | ITHJ=1 | |
23 | ELSE | |
24 | ITHJ=0 | |
25 | END IF | |
26 | RS=SQRT(S) | |
27 | K=SQRT(S*S+(MZI**2-MZJ**2)**2-2*S*(MZI**2+MZJ**2))/ | |
28 | $ 2./RS | |
29 | TPP=S*S-(MZI**2-MZJ**2)**2-4*K*S**1.5*Z+4*K*K*S*Z*Z | |
30 | TPM=S*S-(MZI**2-MZJ**2)**2+4*K*S**1.5*Z+4*K*K*S*Z*Z | |
31 | BTP=(S-MZI**2-MZJ**2)/2.-RS*K*Z+AMSQ**2 | |
32 | BTM=(S-MZI**2-MZJ**2)/2.+RS*K*Z+AMSQ**2 | |
33 | SSGT=(TPP/BTP**2+TPM/BTM**2-8*(-1.)**(ITHI+ITHJ)* | |
34 | $ MZI*MZJ*S/BTM/BTP)/16. | |
35 | RETURN | |
36 | END |