ISAJET/code/sigint.F

   1 #include "isajet/pilot.h"
   2       SUBROUTINE SIGINT(F,Z,A1S,B1S,A2S,B2S)
   3 C
   4 C          F(N+1) = INT(-Z,Z)(DX X**N/((A1+B1*X)*A2+B2*X)))
   5 C          F(8) = F(9) = 0 (DUMMY VALUES)
   6 C
   7       DIMENSION F(9)
   8 #if defined(CERNLIB_DOUBLE)
   9       DOUBLE PRECISION A1,B1,A2,B2,A,B,C,Z,F,A1S,B1S,A2S,B2S
  10 #endif
  11 C
  12       A1=A1S
  13       B1=B1S
  14       A2=A2S
  15       B2=B2S
  16       F(8)=0.
  17       F(9)=0.
  18 C
  19 C          SPECIAL CASE: X**N/(A1*A2)
  20       IF(B1.EQ.0..AND.B2.EQ.0.) THEN
  21         F(1)=2.*Z/(A1*A2)
  22         F(2)=0.
  23         F(3)=2.*Z**3/(3.*A1*A2)
  24         F(4)=0.
  25         F(5)=2.*Z**5/(5.*A1*A2)
  26         F(6)=0.
  27         F(7)=2.*Z**7/(7.*A1*A2)
  28         RETURN
  29       ENDIF
  30 C
  31 C          SPECIAL CASE: X**N/(A+BX)
  32       IF(B1.EQ.0..OR.B2.EQ.0.) THEN
  33         IF(B1.EQ.0.) THEN
  34           A=A2/B2
  35           C=1./(A1*B2)
  36         ELSE
  37           A=A1/B1
  38           C=1./(A2*B1)
  39         ENDIF
  40         F(1)=LOG((A+Z)/(A-Z))
  41         F(1)=F(1)*C
  42         F(2)=-A*LOG((A+Z)/(A-Z))+2.*Z
  43         F(2)=F(2)*C
  44         F(3)=A**2*LOG((A+Z)/(A-Z))-2.*A*Z
  45         F(3)=F(3)*C
  46         F(4)=-A**3*LOG((A+Z)/(A-Z))+2.*A**2*Z+2.*Z**3/3.
  47         F(4)=F(4)*C
  48         F(5)=A**4*LOG((A+Z)/(A-Z))-2.*A**3*Z-2.*A*Z**3/3.
  49         F(5)=F(5)*C
  50         F(6)=-A**5*LOG((A+Z)/(A-Z))+2.*A**4*Z+2.*A**2*Z**3/3.+2.*Z**5/5.
  51         F(6)=F(6)*C
  52         F(7)=A**6*LOG((A+Z)/(A-Z))-2.*A**5*Z-2.*A**3*Z**3/3.
  53      $  -2.*A*Z**5/5.
  54         F(7)=F(7)*C
  55         RETURN
  56       ENDIF
  57 C
  58 C          B1 AND B2 NONZERO
  59       A1=A1/B1
  60       A2=A2/B2
  61       C=1./(B1*B2)
  62 C
  63 C          SPECIAL CASE: X**N/(A+B*X)**2
  64       IF(A1.EQ.A2) THEN
  65         A=A1
  66         F(1)=2.*Z/(A**2-Z**2)
  67         F(1)=F(1)*C
  68         F(2)=-2.*A*Z/(A**2-Z**2)+LOG((A+Z)/(A-Z))
  69         F(2)=F(2)*C
  70         F(3)=(4.*A**2*Z-2.*Z**3)/(A**2-Z**2)-2.*A*LOG((A+Z)/(A-Z))
  71         F(3)=F(3)*C
  72         F(4)=(4.*A*Z**3-6.*A**3*Z)/(A**2-Z**2)+3.*A**2*LOG((A+Z)/(A-Z))
  73         F(4)=F(4)*C
  74         F(5)=(-16.*A**2*Z**3/3.+8.*A**4*Z-2.*Z**5/3.)/(A**2-Z**2)
  75      $  -4.*A**3*LOG((A+Z)/(A-Z))
  76         F(5)=F(5)*C
  77         F(6)=(4.*A*Z**5/3.+20.*A**3*Z**3/3.-10.*A**5*Z)/(A**2-Z**2)
  78      $  +5*A**4*LOG((A+Z)/(A-Z))
  79         F(6)=F(6)*C
  80         F(7)=(-8.*A**2*Z**5/5.-8.*A**4*Z**3+12.*A**6*Z-2.*Z**7/5.)
  81      $  /(A**2-Z**2)-6.*A**5*LOG((A+Z)/(A-Z))
  82         F(7)=F(7)*C
  83         RETURN
  84       ENDIF
  85 C
  86 C          GENERAL CASE
  87       F(1)=(-LOG((A1+Z)/(A1-Z))+LOG((A2+Z)/(A2-Z)))/(A1-A2)
  88       F(1)=F(1)*C
  89       F(2)=(A1*LOG((A1+Z)/(A1-Z))-A2*LOG((A2+Z)/(A2-Z)))/(A1-A2)
  90       F(2)=F(2)*C
  91       F(3)=(-A1**2*LOG((A1+Z)/(A1-Z))+A2**2*LOG((A2+Z)/(A2-Z)))/(A1-A2)
  92      $+2.*Z
  93       F(3)=F(3)*C
  94       F(4)=(A1**3*LOG((A1+Z)/(A1-Z))-A2**3*LOG((A2+Z)/(A2-Z)))/(A1-A2)
  95      $+2.*Z*(-A1-A2)
  96       F(4)=F(4)*C
  97       F(5)=(-A1**4*LOG((A1+Z)/(A1-Z))+A2**4*LOG((A2+Z)/(A2-Z)))/(A1-A2)
  98      $+2.*Z*(A1*A2+A1**2+A2**2)+2.*Z**3/3.
  99       F(5)=F(5)*C
 100       F(6)=(A1**5*LOG((A1+Z)/(A1-Z))-A2**5*LOG((A2+Z)/(A2-Z)))/(A1-A2)
 101      $+2.*Z*(-A1*A2**2-A1**2*A2-A1**3-A2**3)+2.*Z**3/3.*(-A1-A2)
 102       F(6)=F(6)*C
 103       F(7)=(-A1**6*LOG((A1+Z)/(A1-Z))+A2**6*LOG((A2+Z)/(A2-Z)))/(A1-A2)
 104      $+2.*Z*(A1*A2**3+A1**2*A2**2+A1**3*A2+A1**4+A2**4)
 105      $+2.*Z**3/3.*(A1*A2+A1**2+A2**2)+2.*Z**5/5.
 106       F(7)=F(7)*C
 107       RETURN
 108       END