HIJING/hijing1_36/arorie.F

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