Added the magnetic field as a static member of the AliL3Transform class,

[u/mrichter/AliRoot.git] / ISAJET / code / zjj1.F

#include "isajet/pilot.h"
      REAL*8 FUNCTION ZJJ1(P1, P2, P3, P4, P5,NHEL,IM1,IM2)
C  
C Function generated by Madgraph + hand coding
C Returns amplitude squared summed/avg over colors
C for the point in phase space P1,P2,P3,P4,...
C and helicity NHEL(1),NHEL(2),....
C for process : q(im1) q~(im1)  -> z q(im2) q~(im2)
C with Madgraph codes IM1 != IM2  
C  
#if defined(CERNLIB_IMPNONE)
      IMPLICIT NONE
#endif
C  
C CONSTANTS
C  
      INTEGER    NGRAPHS,    NEIGEN,    NEXTERNAL       
      PARAMETER (NGRAPHS=  4,NEIGEN=  1,NEXTERNAL=5)    
      REAL*8     ZERO
      PARAMETER (ZERO=0D0)
C  
C ARGUMENTS 
C  
      REAL*8 P1(0:3),P2(0:3),P3(0:3),P4(0:3),P5(0:3)                             
      INTEGER NHEL(NEXTERNAL)                                                    
      INTEGER IM1,IM2
C  
C LOCAL VARIABLES 
C  
      INTEGER I,J
      REAL*8 EIGEN_VAL(NEIGEN), EIGEN_VEC(NGRAPHS,NEIGEN)
      COMPLEX*16 ZTEMP
      COMPLEX*16 AMP(NGRAPHS)
      COMPLEX*16 W1(6)  , W2(6)  , W3(6)  , W4(6)  , W5(6)        
      COMPLEX*16 W6(6)  , W7(6)  , W8(6)  , W9(6)  , W10(6)       
      COMPLEX*16 W11(6) , W12(6) 
C  
C GLOBAL VARIABLES
C  
#include "isajet/mgcoms.inc"
C  
C COLOR DATA
C  
      DATA EIGEN_VAL(1  )/       8.8888888888888884D-01 /                  
      DATA EIGEN_VEC(1  ,1  )/  -5.0000000000000000D-01 /                  
      DATA EIGEN_VEC(2  ,1  )/  -5.0000000000000000D-01 /                  
      DATA EIGEN_VEC(3  ,1  )/  -5.0000000000000000D-01 /                  
      DATA EIGEN_VEC(4  ,1  )/  -5.0000000000000000D-01 /                  
C ----------
C BEGIN CODE
C ----------
      CALL IXXXXX(P1  ,FMASS(IM1),NHEL(1  ), 1,W1  )                       
      CALL OXXXXX(P2  ,FMASS(IM1),NHEL(2  ),-1,W2  )                       
      CALL VXXXXX(P3  ,ZMASS,NHEL(3  ), 1,W3  )                            
      CALL OXXXXX(P4  ,FMASS(IM2),NHEL(4  ), 1,W4  )                       
      CALL IXXXXX(P5  ,FMASS(IM2),NHEL(5  ),-1,W5  )                       
      IF(IM1.EQ.3.OR.IM1.EQ.7.OR.IM1.EQ.11) THEN
        CALL FVOXXX(W2  ,W3  ,GZD,FMASS(IM1),FWIDTH(IM1),W6  )               
      ELSE
        CALL FVOXXX(W2  ,W3  ,GZU,FMASS(IM1),FWIDTH(IM1),W6  )               
      ENDIF
      CALL JIOXXX(W1  ,W6  ,GG,ZERO,ZERO,W7  )                             
      CALL IOVXXX(W5  ,W4  ,W7  ,GG,AMP(1  ))                              
      CALL FVIXXX(W1  ,W3  ,GZD,FMASS(IM1),FWIDTH(IM2),W8  )               
      CALL JIOXXX(W8  ,W2  ,GG,ZERO,ZERO,W9  )                             
      CALL IOVXXX(W5  ,W4  ,W9  ,GG,AMP(2  ))                              
      CALL JIOXXX(W1  ,W2  ,GG,ZERO,ZERO,W10 )                             
      CALL FVOXXX(W4  ,W10 ,GG,FMASS(IM2),FWIDTH(IM2),W11 )                
      CALL IOVXXX(W5  ,W11 ,W3  ,GZD,AMP(3  ))                             
      IF(IM2.EQ.3.OR.IM2.EQ.7.OR.IM2.EQ.11) THEN
        CALL FVOXXX(W4  ,W3  ,GZD,FMASS(IM2),FWIDTH(IM2),W12 )               
      ELSE
        CALL FVOXXX(W4  ,W3  ,GZU,FMASS(IM2),FWIDTH(IM2),W12 )
      ENDIF
      CALL IOVXXX(W5  ,W12 ,W10 ,GG,AMP(4  ))                              
      ZJJ1 = 0.D0 
      DO I = 1, NEIGEN
          ZTEMP = (0.D0,0.D0)
          DO J = 1, NGRAPHS
              ZTEMP = ZTEMP + EIGEN_VEC(J,I)*AMP(J)
          ENDDO
          ZJJ1 =ZJJ1+ZTEMP*EIGEN_VAL(I)*CONJG(ZTEMP) 
      ENDDO
C      CALL GAUGECHECK(AMP,ZTEMP,EIGEN_VEC,EIGEN_VAL,NGRAPHS,NEIGEN)
      END