ISAJET/code/sigtc.F

   1 #include "isajet/pilot.h"
   2       SUBROUTINE SIGTC
   3 C
   4 C          Compute the integrated technirho cross section
   5 C          d(sigma)/d(qmw**2)d(yw) = d(sigma)/d(qmw**2)*f(x1)*f(x2)/scm
   6 C          including W-technirho mixing from EHLQ 6.22 and 6.23 and
   7 C          elastic resonance in longitudinal WW fusion.
   8 C
   9 C          Use WTYPE for control with
  10 C          WTYPE = 2     3     4
  11 C                  rho+  rho-  rho0
  12 C
  13 C          SIGMA    = cross section summed over allowed types.
  14 C          SIGS(I)  = partial cross section for I1 + I2 --> I3 + I4.
  15 C          INOUT(I) = IOPAK**3*I4 + IOPAK**2*I3 + IOPAK*I2 + I1
  16 C                     using JETTYPE code.
  17 C
  18 #if defined(CERNLIB_IMPNONE)
  19       IMPLICIT NONE
  20 #endif
  21 #include "isajet/itapes.inc"
  22 #include "isajet/qcdpar.inc"
  23 #include "isajet/jetpar.inc"
  24 #include "isajet/primar.inc"
  25 #include "isajet/q1q2.inc"
  26 #include "isajet/jetsig.inc"
  27 #include "isajet/qsave.inc"
  28 #include "isajet/wcon.inc"
  29 #include "isajet/const.inc"
  30 #include "isajet/jetlim.inc"
  31 #include "isajet/hcon.inc"
  32 #include "isajet/tcpar.inc"
  33 C
  34       REAL AMQCUR(6),WTHELI(4),FINT(9),X(2)
  35       EQUIVALENCE (S,SHAT),(T,THAT),(U,UHAT),(X(1),X1)
  36       INTEGER MATCHT(4,4)
  37       REAL ACOSH,Z,ATANH,AMASS,QMW2,QMZ,EHAT,ANEFF,Q2SAVE,YHAT,EY,AMW,
  38      $AMZ,STRUC,STRUCW,WM,ZM,PWWCM,SIG0,S,T,U,FACINV,RATZ,Q1L,Q1R,SIG1,
  39      $SIG,QZW
  40       INTEGER I,IH,IQ,IW,IQ1,IQ2,IQ3,IQ4,IRHO,LISTW(4)
  41 C
  42       DATA AMQCUR/.005,.009,.175,1.25,4.50,30./
  43       DATA LISTW/10,80,-80,90/
  44       DATA MATCHT/0,0,0,0, 0,29,0,27, 0,0,29,28, 0,28,27,0/
  45 C
  46 C          Functions
  47       ACOSH(Z)=ALOG(Z+SQRT(Z**2-1.))
  48       ATANH(Z)=.5*ALOG((1.+Z)/(1.-Z))
  49 C
  50 C          Kinematics (identical to Drell-Yan)
  51 C
  52       AMQCUR(6)=AMASS(6)
  53       QMW2=QMW**2
  54       QTMW=SQRT(QMW2+QTW**2)
  55       Q0W=QTMW*COSH(YW)
  56       QZW=QTMW*SINH(YW)
  57       QW=SQRT(QZW**2+QTW**2)
  58       IF(QW.NE.0.) THEN
  59         CTHW=QZW/QW
  60         STHW=QTW/QW
  61         IF(ABS(CTHW).LT.1.) THEN
  62           THW=ACOS(CTHW)
  63         ELSE
  64           CTHW=0.
  65           STHW=1.
  66           THW=.5*PI
  67         ENDIF
  68       ELSE
  69         CTHW=0.
  70         STHW=1.
  71         THW=.5*PI
  72       ENDIF
  73       EHAT=QMW
  74       SHAT=QMW**2
  75       QSQ=SHAT
  76       ANEFF=4.+QSQ/(QSQ+AMASS(5)**2)+QSQ/(QSQ+AMASS(6)**2)
  77       ALFQSQ=12.*PI/((33.-ANEFF)*ALOG(QSQ/ALAM2))
  78       Q2SAVE=QSQ
  79       YHAT=YW
  80       EY=EXP(YHAT)
  81       X1=EHAT/ECM*EY
  82       X2=EHAT/(ECM*EY)
  83 C
  84 C          Initialize
  85 C
  86       SIGMA=0.
  87       NSIGS=0
  88       DO 100 I=1,MXSIGS
  89 100   SIGS(I)=0
  90 C
  91       IF(X1.GE.1..OR.X2.GE.1.) RETURN
  92       AMW=WMASS(2)
  93       AMZ=WMASS(4)
  94 C
  95 C          Compute structure functions
  96 C
  97       DO 110 IH=1,2
  98         DO 120 IQ=1,13
  99 120     QSAVE(IQ,IH)=STRUC(X(IH),QSQ,IQ,IDIN(IH))/X(IH)
 100         DO 130 IQ=14,26
 101 130     QSAVE(IQ,IH)=0.
 102         DO 140 IW=2,4
 103           AMW=AMASS(LISTW(IW))
 104           IF(QMW.GT.2.*AMW) THEN
 105             QSAVE(25+IW,IH)=STRUCW(X(IH),IW,IDIN(IH))/X(IH)
 106           ELSE
 107             QSAVE(25+IW,IH)=0.
 108           ENDIF
 109 140     CONTINUE
 110 110   CONTINUE
 111 C
 112 C          qk + qb --> technirho0
 113 C
 114       IF(.NOT.((GOQ(27,1).AND.GOQ(28,2)).OR.(GOQ(28,1).AND.GOQ(27,2))))
 115      $GO TO 300
 116       WM=WMASS(2)
 117       ZM=WMASS(4)
 118       IF(QMW.LE.2.*AMW) GO TO 300
 119       PWWCM=.5*SQRT(QMW**2-4.*WM**2)
 120       SIG0=PI*ALFA**2/(72.*SIN2W*S)*(2.*PWWCM/QMW)**3*X1*X2*UNITS
 121       SIG0=SIG0*TCMRHO**2/((S-TCMRHO**2)**2+TCMRHO**2*TCGRHO**2)
 122 C          Initial state sum
 123       DO 210 IQ1=2,13
 124         IQ2=MATCH(IQ1,4)
 125         IF(IQ2.EQ.0) GO TO 210
 126         FACINV=2.*SQRT(SIN2W*(1.-SIN2W))
 127         RATZ=S/(S-ZM**2)
 128         Q1L=AQ(IQ1/2,4)*FACINV
 129         Q1R=BQ(IQ1/2,4)*FACINV
 130         SIG1=.25*SIG0*(1.-RATZ*Q1L/(Q1R*(1.-SIN2W))
 131      $  +RATZ**2*(Q1L**2+Q1R**2)/(4.*(1-SIN2W)**2))
 132      $  *QSAVE(IQ1,1)*QSAVE(IQ2,2)
 133 C          Final state sum
 134         DO 220 IQ3=27,28
 135           IQ4=MATCHT(IQ3-25,4)
 136           IF(GOQ(IQ3,1).AND.GOQ(IQ4,2)) THEN
 137             SIG=SIG1*TBRWW(IQ3-25,1)*TBRWW(IQ4-25,2)
 138             CALL SIGFIL(SIG,IQ1,IQ2,IQ3,IQ4)
 139           ENDIF
 140 220     CONTINUE
 141 210   CONTINUE
 142 C
 143 C          W+ + W- -> technirho0 -> W+ + W-
 144 C
 145       SIG0=12*PI/PWWCM**2*TCGRHO**2*X1*X2*UNITS
 146      $/((S-TCMRHO**2)**2+TCMRHO**2*TCGRHO**2)
 147 C          Initial state sum
 148       DO 230 IQ1=27,28
 149         IQ2=MATCHT(IQ1-25,4)
 150         SIG1=.25*SIG0*QSAVE(IQ1,1)*QSAVE(IQ2,2)
 151 C          Final state sum
 152         DO 240 IQ3=27,28
 153           IQ4=MATCHT(IQ3-25,4)
 154           IF(GOQ(IQ3,1).AND.GOQ(IQ4,2)) THEN
 155             SIG=SIG1*TBRWW(IQ3-25,1)*TBRWW(IQ4-25,2)
 156             CALL SIGFIL(SIG,IQ1,IQ2,IQ3,IQ4)
 157           ENDIF
 158 240     CONTINUE
 159 230   CONTINUE
 160 C
 161 C          q + qbar -> technirho+-
 162 C
 163 300   IF(.NOT.((GOQ(27,1).AND.GOQ(29,2)).OR.(GOQ(28,1).AND.GOQ(29,2))
 164      $.OR.(GOQ(29,1).AND.GOQ(27,2)).OR.(GOQ(29,1).AND.GOQ(28,2))))
 165      $GO TO 400
 166       WM=WMASS(2)
 167       ZM=WMASS(4)
 168       IF(QMW.LE.WM+ZM) GO TO 400
 169       PWWCM=SQRT((S-WM**2-ZM**2)**2-4.*WM**2*ZM**2)/(2.*QMW)
 170       SIG0=PI*ALFA**2/(144.*SIN2W)*S/(S-WM**2)**2*(2.*PWWCM/QMW)**3
 171      $*X1*X2*UNITS
 172       SIG0=SIG0*TCMRHO**2/((S-TCMRHO**2)**2+TCMRHO**2*TCGRHO**2)
 173       DO 310 IRHO=2,3
 174 C          Initial state sum
 175         DO 320 IQ1=2,13
 176           IQ2=MATCH(IQ1,IRHO)
 177           IF(IQ2.EQ.0) GO TO 320
 178           SIG1=.25*SIG0*QSAVE(IQ1,1)*QSAVE(IQ2,2)
 179 C          Final state sum
 180           DO 330 IQ3=27,28
 181             IQ4=MATCHT(IQ3-25,IRHO)
 182             IF(IQ4.EQ.0) GO TO 330
 183             IF(GOQ(IQ3,1).AND.GOQ(IQ4,2)) THEN
 184               SIG=SIG1*TBRWW(IQ3-25,1)*TBRWW(IQ4-25,2)
 185               CALL SIGFIL(SIG,IQ1,IQ2,IQ3,IQ4)
 186             ENDIF
 187 330       CONTINUE
 188 320     CONTINUE
 189 310   CONTINUE
 190 C
 191 C          W+- + Z0 -> technirho+- -> W+- + Z0
 192 C
 193       SIG0=12*PI/PWWCM**2*TCGRHO**2*X1*X2*UNITS
 194      $/((S-TCMRHO**2)**2+TCMRHO**2*TCGRHO**2)
 195       DO 340 IRHO=2,3
 196 C          Initial state sum
 197         DO 350 IQ1=27,29
 198           IQ2=MATCHT(IQ1-25,IRHO)
 199           IF(IQ2.EQ.0) GO TO 350
 200           SIG1=.25*SIG0*QSAVE(IQ1,1)*QSAVE(IQ2,2)
 201 C          Final state sum
 202           DO 360 IQ3=27,29
 203             IQ4=MATCHT(IQ3-25,IRHO)
 204             IF(IQ4.EQ.0) GO TO 360
 205             IF(GOQ(IQ3,1).AND.GOQ(IQ4,2)) THEN
 206               SIG=SIG1*TBRWW(IQ3-25,1)*TBRWW(IQ4-25,2)
 207               CALL SIGFIL(SIG,IQ1,IQ2,IQ3,IQ4)
 208             ENDIF
 209 360       CONTINUE
 210 350     CONTINUE
 211 340   CONTINUE
 212 C
 213 400   RETURN
 214       END