HIJING/hipyset1_35/lufowo_hijing.F

   1 * $Id$
   2
   3 C*********************************************************************
   4
   5       SUBROUTINE LUFOWO_HIJING(H10,H20,H30,H40)
   6
   7 C...Purpose: to calculate the first few Fox-Wolfram moments.
   8 #include "lujets_hijing.inc"
   9 #include "ludat1_hijing.inc"
  10 #include "ludat2_hijing.inc"
  11
  12 C...Copy momenta for particles and calculate H0.
  13       NP=0
  14       H0=0.
  15       HD=0.
  16       DO 110 I=1,N
  17       IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 110
  18       IF(MSTU(41).GE.2) THEN
  19         KC=LUCOMP_HIJING(K(I,2))
  20         IF(KC.EQ.0.OR.KC.EQ.12.OR.KC.EQ.14.OR.KC.EQ.16.OR.
  21      &  KC.EQ.18) GOTO 110
  22         IF(MSTU(41).GE.3.AND.KCHG(KC,2).EQ.0.AND.LUCHGE_HIJING(K(I,2))
  23      $       .EQ.0)GOTO 110
  24       ENDIF
  25       IF(N+NP.GE.MSTU(4)-MSTU(32)-5) THEN
  26          CALL LUERRM_HIJING(11
  27      $        ,'(LUFOWO_HIJING:) no more memory left in LUJETS_HIJING')
  28         H10=-1.
  29         H20=-1.
  30         H30=-1.
  31         H40=-1.
  32         RETURN
  33       ENDIF
  34       NP=NP+1
  35       DO 100 J=1,3
  36   100 P(N+NP,J)=P(I,J)
  37       P(N+NP,4)=SQRT(P(I,1)**2+P(I,2)**2+P(I,3)**2)
  38       H0=H0+P(N+NP,4)
  39       HD=HD+P(N+NP,4)**2
  40   110 CONTINUE
  41       H0=H0**2
  42
  43 C...Very low multiplicities (0 or 1) not considered.
  44       IF(NP.LE.1) THEN
  45          CALL LUERRM_HIJING(8
  46      $        ,'(LUFOWO_HIJING:) too few particles for analysis')
  47         H10=-1.
  48         H20=-1.
  49         H30=-1.
  50         H40=-1.
  51         RETURN
  52       ENDIF
  53
  54 C...Calculate H1 - H4.
  55       H10=0.
  56       H20=0.
  57       H30=0.
  58       H40=0.
  59       DO 120 I1=N+1,N+NP
  60       DO 120 I2=I1+1,N+NP
  61       CTHE=(P(I1,1)*P(I2,1)+P(I1,2)*P(I2,2)+P(I1,3)*P(I2,3))/
  62      &(P(I1,4)*P(I2,4))
  63       H10=H10+P(I1,4)*P(I2,4)*CTHE
  64       H20=H20+P(I1,4)*P(I2,4)*(1.5*CTHE**2-0.5)
  65       H30=H30+P(I1,4)*P(I2,4)*(2.5*CTHE**3-1.5*CTHE)
  66       H40=H40+P(I1,4)*P(I2,4)*(4.375*CTHE**4-3.75*CTHE**2+0.375)
  67   120 CONTINUE
  68
  69 C...Calculate H1/H0 - H4/H0. Output.
  70       MSTU(61)=N+1
  71       MSTU(62)=NP
  72       H10=(HD+2.*H10)/H0
  73       H20=(HD+2.*H20)/H0
  74       H30=(HD+2.*H30)/H0
  75       H40=(HD+2.*H40)/H0
  76
  77       RETURN
  78       END