HIJING/hijing1_36/arorie.F

   1 * $Id$
   2 C*************************************************************
   3
   4
   5         SUBROUTINE ARORIE(S,X1,X3,JL)
   6 C
   7 #include "hiparnt.inc"
   8 #include "lujets_hijing.inc"
   9         SAVE
  10 C
  11         W=SQRT(S)
  12         X2=2.-X1-X3
  13         E1=.5*X1*W
  14         E3=.5*X3*W
  15         P1=SQRT(E1**2-P(JL,5)**2)
  16         P3=SQRT(E3**2-P(JL+1,5)**2)
  17         CBET=1.
  18         IF(P1.GT.0..AND.P3.GT.0.) CBET=(P(JL,5)**2
  19      &           +P(JL+1,5)**2+2.*E1*E3-S*(1.-X2))/(2.*P1*P3)
  20         IF(ABS(CBET).GT.1.0) CBET=MAX(-1.,MIN(1.,CBET))
  21         BET=ACOS(CBET)
  22
  23 C.....MINIMIZE PT1-SQUARED PLUS PT3-SQUARED.....
  24         IF(P1.GE.P3) THEN
  25            PSI=.5*ULANGL_HIJING(P1**2+P3**2*COS(2.*BET),-P3**2*SIN(2.
  26      1  *BET))
  27            PT1=P1*SIN(PSI)
  28            PZ1=P1*COS(PSI)
  29            PT3=P3*SIN(PSI+BET)
  30            PZ3=P3*COS(PSI+BET)
  31         ELSE IF(P3.GT.P1) THEN
  32            PSI=.5*ULANGL_HIJING(P3**2+P1**2*COS(2.*BET),-P1**2*SIN(2.
  33      1  *BET))
  34            PT1=P1*SIN(BET+PSI)
  35            PZ1=-P1*COS(BET+PSI)
  36            PT3=P3*SIN(PSI)
  37            PZ3=-P3*COS(PSI)
  38         ENDIF
  39
  40         DEL=2.0*HIPR1(40)*RLU_HIJING(0)
  41         P(JL,4)=E1
  42         P(JL,1)=PT1*SIN(DEL)
  43         P(JL,2)=-PT1*COS(DEL)
  44         P(JL,3)=PZ1
  45         P(JL+2,4)=E3
  46         P(JL+2,1)=PT3*SIN(DEL)
  47         P(JL+2,2)=-PT3*COS(DEL)
  48         P(JL+2,3)=PZ3
  49         P(JL+1,4)=W-E1-E3
  50         P(JL+1,1)=-P(JL,1)-P(JL+2,1)
  51         P(JL+1,2)=-P(JL,2)-P(JL+2,2)
  52         P(JL+1,3)=-P(JL,3)-P(JL+2,3)
  53         RETURN
  54         END