PYTHIA/pythia/pyqqbh.F

   1
   2 C***********************************************************************
   3
   4       SUBROUTINE PYQQBH(WTQQBH)
   5
   6 C...Calculates the matrix element for the processes
   7 C...g + g or q + qbar -> Q + Q~ + H (normally with Q = t).
   8 C...REDUCE output and part of the rest courtesy Z. Kunszt, see
   9 C...Z. Kunszt, Nucl. Phys. B247 (1984) 339.
  10       COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
  11       COMMON/LUDAT2/KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4)
  12       COMMON/PYPARS/MSTP(200),PARP(200),MSTI(200),PARI(200)
  13       COMMON/PYINT1/MINT(400),VINT(400)
  14       COMMON/PYINT2/ISET(200),KFPR(200,2),COEF(200,20),ICOL(40,4,2)
  15       SAVE /LUDAT1/,/LUDAT2/
  16       SAVE /PYPARS/,/PYINT1/,/PYINT2/
  17       DIMENSION PP(15,4),CLR(8,8),FM(10,10),RM(8,8),DX(8)
  18       DOT(I,J)=PP(I,4)*PP(J,4)-PP(I,1)*PP(J,1)-PP(I,2)*PP(J,2)-
  19      &PP(I,3)*PP(J,3)
  20
  21 C...Mass parameters.
  22       WTQQBH=0.
  23       ISUB=MINT(1)
  24       SHPR=SQRT(VINT(26))*VINT(1)
  25       PQ=PMAS(KFPR(ISUB,2),1)
  26       PH=SQRT(VINT(21))*VINT(1)
  27       SPQ=PQ**2
  28       SPH=PH**2
  29
  30 C...Set up outgoing kinematics: 1=t, 2=tbar, 3=H.
  31       DO 100 I=1,2
  32       PT=SQRT(MAX(0.,VINT(197+5*I)))
  33       PP(I,1)=PT*COS(VINT(198+5*I))
  34       PP(I,2)=PT*SIN(VINT(198+5*I))
  35   100 CONTINUE
  36       PP(3,1)=-PP(1,1)-PP(2,1)
  37       PP(3,2)=-PP(1,2)-PP(2,2)
  38       PMS1=SPQ+PP(1,1)**2+PP(1,2)**2
  39       PMS2=SPQ+PP(2,1)**2+PP(2,2)**2
  40       PMS3=SPH+PP(3,1)**2+PP(3,2)**2
  41       PMT3=SQRT(PMS3)
  42       PP(3,3)=PMT3*SINH(VINT(211))
  43       PP(3,4)=PMT3*COSH(VINT(211))
  44       PMS12=(SHPR-PP(3,4))**2-PP(3,3)**2
  45       PP(1,3)=(-PP(3,3)*(PMS12+PMS1-PMS2)+
  46      &VINT(213)*(SHPR-PP(3,4))*VINT(220))/(2.*PMS12)
  47       PP(2,3)=-PP(1,3)-PP(3,3)
  48       PP(1,4)=SQRT(PMS1+PP(1,3)**2)
  49       PP(2,4)=SQRT(PMS2+PP(2,3)**2)
  50
  51 C...Set up incoming kinematics and derived momentum combinations.
  52       DO 110 I=4,5
  53       PP(I,1)=0.
  54       PP(I,2)=0.
  55       PP(I,3)=-0.5*SHPR*(-1)**I
  56       PP(I,4)=-0.5*SHPR
  57   110 CONTINUE
  58       DO 120 J=1,4
  59       PP(6,J)=PP(1,J)+PP(2,J)
  60       PP(7,J)=PP(1,J)+PP(3,J)
  61       PP(8,J)=PP(1,J)+PP(4,J)
  62       PP(9,J)=PP(1,J)+PP(5,J)
  63       PP(10,J)=-PP(2,J)-PP(3,J)
  64       PP(11,J)=-PP(2,J)-PP(4,J)
  65       PP(12,J)=-PP(2,J)-PP(5,J)
  66       PP(13,J)=-PP(4,J)-PP(5,J)
  67   120 CONTINUE
  68
  69 C...Derived kinematics invariants.
  70       X1=DOT(1,2)
  71       X2=DOT(1,3)
  72       X3=DOT(1,4)
  73       X4=DOT(1,5)
  74       X5=DOT(2,3)
  75       X6=DOT(2,4)
  76       X7=DOT(2,5)
  77       X8=DOT(3,4)
  78       X9=DOT(3,5)
  79       X10=DOT(4,5)
  80
  81 C...Propagators.
  82       SS1=DOT(7,7)-SPQ
  83       SS2=DOT(8,8)-SPQ
  84       SS3=DOT(9,9)-SPQ
  85       SS4=DOT(10,10)-SPQ
  86       SS5=DOT(11,11)-SPQ
  87       SS6=DOT(12,12)-SPQ
  88       SS7=DOT(13,13)
  89       DX(1)=SS1*SS6
  90       DX(2)=SS2*SS6
  91       DX(3)=SS2*SS4
  92       DX(4)=SS1*SS5
  93       DX(5)=SS3*SS5
  94       DX(6)=SS3*SS4
  95       DX(7)=SS7*SS1
  96       DX(8)=SS7*SS4
  97
  98 C...Define colour coefficients for g + g -> Q + Q~ + H.
  99       IF(ISUB.EQ.121.OR.ISUB.EQ.181.OR.ISUB.EQ.186) THEN
 100         DO 140 I=1,3
 101         DO 130 J=1,3
 102         CLR(I,J)=16./3.
 103         CLR(I+3,J+3)=16./3.
 104         CLR(I,J+3)=-2./3.
 105         CLR(I+3,J)=-2./3.
 106   130   CONTINUE
 107   140   CONTINUE
 108         DO 160 L=1,2
 109         DO 150 I=1,3
 110         CLR(I,6+L)=-6.
 111         CLR(I+3,6+L)=6.
 112         CLR(6+L,I)=-6.
 113         CLR(6+L,I+3)=6.
 114   150   CONTINUE
 115   160   CONTINUE
 116         DO 180 K1=1,2
 117         DO 170 K2=1,2
 118         CLR(6+K1,6+K2)=12.
 119   170   CONTINUE
 120   180   CONTINUE
 121
 122 C...Evaluate matrix elements for g + g -> Q + Q~ + H.
 123       FM(1,1)=64*PQ**6+16*PQ**4*PH**2+32*PQ**4*(X1+2*X2+X4+X9+2*
 124      & X7+X5)+8*PQ**2*PH**2*(-X1-X4+2*X7)+16*PQ**2*(X2*X9+4*X2*
 125      & X7+X2*X5-2*X4*X7-2*X9*X7)+8*PH**2*X4*X7-16*X2*X9*X7
 126       FM(1,2)=16*PQ**6+8*PQ**4*(-2*X1+X2-2*X3-2*X4-4*X10+X9-X8+2
 127      & *X7-4*X6+X5)+8*PQ**2*(-2*X1*X2-2*X2*X4-2*X2*X10+X2*X7-2*
 128      & X2*X6-2*X3*X7+2*X4*X7+4*X10*X7-X9*X7-X8*X7)+16*X2*X7*(X4+
 129      & X10)
 130       FM(1,3)=16*PQ**6-4*PQ**4*PH**2+8*PQ**4*(-2*X1+2*X2-2*X3-4*
 131      & X4-8*X10+X9+X8-2*X7-4*X6+2*X5)-(4*PQ**2*PH**2)*(X1+X4+X10
 132      & +X6)+8*PQ**2*(-2*X1*X2-2*X1*X10+X1*X9+X1*X8-2*X1*X5+X2**2
 133      & -4*X2*X4-5*X2*X10+X2*X8-X2*X7-3*X2*X6+X2*X5+X3*X9+2*X3*X7
 134      & -X3*X5+X4*X8+2*X4*X6-3*X4*X5-5*X10*X5+X9*X8+X9*X6+X9*X5+
 135      & X8*X7-4*X6*X5+X5**2)-(16*X2*X5)*(X1+X4+X10+X6)
 136       FM(1,4)=16*PQ**6+4*PQ**4*PH**2+16*PQ**4*(-X1+X2-X3-X4+X10-
 137      & X9-X8+2*X7+2*X6-X5)+4*PQ**2*PH**2*(X1+X3+X4+X10+2*X7+2*X6
 138      & )+8*PQ**2*(4*X1*X10+4*X1*X7+4*X1*X6+2*X2*X10-X2*X9-X2*X8+
 139      & 4*X2*X7+4*X2*X6-X2*X5+4*X10*X5+4*X7*X5+4*X6*X5)-(8*PH**2*
 140      & X1)*(X10+X7+X6)+16*X2*X5*(X10+X7+X6)
 141       FM(1,5)=8*PQ**4*(-2*X1-2*X4+X10-X9)+4*PQ**2*(4*X1**2-2*X1*
 142      & X2+8*X1*X3+6*X1*X10-2*X1*X9+4*X1*X8+4*X1*X7+4*X1*X6+2*X1*
 143      & X5+X2*X10+4*X3*X4-X3*X9+2*X3*X7+3*X4*X8-2*X4*X6+2*X4*X5-4
 144      & *X10*X7+3*X10*X5-3*X9*X6+3*X8*X7-4*X7**2+4*X7*X5)+8*(X1**
 145      & 2*X9-X1**2*X8-X1*X2*X7+X1*X2*X6+X1*X3*X9+X1*X3*X5-X1*X4*
 146      & X8-X1*X4*X5+X1*X10*X9+X1*X9*X7+X1*X9*X6-X1*X8*X7-X2*X3*X7
 147      & +X2*X4*X6-X2*X10*X7-X2*X7**2+X3*X7*X5-X4*X10*X5-X4*X7*X5-
 148      & X4*X6*X5)
 149       FM(1,6)=16*PQ**4*(-4*X1-X4+X9-X7)+4*PQ**2*PH**2*(-2*X1-X4-
 150      & X7)+16*PQ**2*(-2*X1**2-3*X1*X2-2*X1*X4-3*X1*X9-2*X1*X7-3*
 151      & X1*X5-2*X2*X4-2*X7*X5)-8*PH**2*X4*X7+8*(-X1*X2*X9-2*X1*X2
 152      & *X5-X1*X9**2-X1*X9*X5+X2**2*X7-X2*X4*X5+X2*X9*X7-X2*X7*X5
 153      & +X4*X9*X5+X4*X5**2)
 154       FM(1,7)=8*PQ**4*(2*X3+X4+3*X10+X9+2*X8+3*X7+6*X6)+2*PQ**2*
 155      & PH**2*(-2*X3-X4+3*X10+3*X7+6*X6)+4*PQ**2*(4*X1*X10+4*X1*
 156      & X7+8*X1*X6+6*X2*X10+X2*X9+2*X2*X8+6*X2*X7+12*X2*X6-8*X3*
 157      & X7+4*X4*X7+4*X4*X6+4*X10*X5+4*X9*X7+4*X9*X6-8*X8*X7+4*X7*
 158      & X5+8*X6*X5)+4*PH**2*(-X1*X10-X1*X7-2*X1*X6+2*X3*X7-X4*X7-
 159      & X4*X6)+8*X2*(X10*X5+X9*X7+X9*X6-2*X8*X7+X7*X5+2*X6*X5)
 160       FM(1,8)=8*PQ**4*(2*X3+X4+3*X10+2*X9+X8+3*X7+6*X6)+2*PQ**2*
 161      & PH**2*(-2*X3-X4+2*X10+X7+2*X6)+4*PQ**2*(4*X1*X10-2*X1*X9+
 162      & 2*X1*X8+4*X1*X7+8*X1*X6+5*X2*X10+2*X2*X9+X2*X8+4*X2*X7+8*
 163      & X2*X6-X3*X9-8*X3*X7+2*X3*X5+2*X4*X9-X4*X8+4*X4*X7+4*X4*X6
 164      & +4*X4*X5+5*X10*X5+X9**2-X9*X8+2*X9*X7+5*X9*X6+X9*X5-7*X8*
 165      & X7+2*X8*X5+2*X7*X5+10*X6*X5)+2*PH**2*(-X1*X10+X3*X7-2*X4*
 166      & X7+X4*X6)+4*(-X1*X9**2+X1*X9*X8-2*X1*X9*X5-X1*X8*X5+2*X2*
 167      & X10*X5+X2*X9*X7+X2*X9*X6-2*X2*X8*X7+3*X2*X6*X5+X3*X9*X5+
 168      & X3*X5**2+X4*X9*X5-2*X4*X8*X5+2*X4*X5**2)
 169       FM(2,2)=16*PQ**6+16*PQ**4*(-X1+X3-X4-X10+X7-X6)+16*PQ**2*(
 170      & X3*X10+X3*X7+X3*X6+X4*X7+X10*X7)-16*X3*X10*X7
 171       FM(2,3)=16*PQ**6+8*PQ**4*(-2*X1+X2+2*X3-4*X4-4*X10-X9+X8-2
 172      & *X7-2*X6+X5)+8*PQ**2*(-2*X1*X5+4*X3*X10-X3*X9-X3*X8-2*X3*
 173      & X7+2*X3*X6+X3*X5-2*X4*X5-2*X10*X5-2*X6*X5)+16*X3*X5*(X10+
 174      & X6)
 175       FM(2,4)=8*PQ**4*(-2*X1-2*X3+X10-X8)+4*PQ**2*(4*X1**2-2*X1*
 176      & X2+8*X1*X4+6*X1*X10+4*X1*X9-2*X1*X8+4*X1*X7+4*X1*X6+2*X1*
 177      & X5+X2*X10+4*X3*X4+3*X3*X9-2*X3*X7+2*X3*X5-X4*X8+2*X4*X6-4
 178      & *X10*X6+3*X10*X5+3*X9*X6-3*X8*X7-4*X6**2+4*X6*X5)+8*(-X1
 179      & **2*X9+X1**2*X8+X1*X2*X7-X1*X2*X6-X1*X3*X9-X1*X3*X5+X1*X4
 180      & *X8+X1*X4*X5+X1*X10*X8-X1*X9*X6+X1*X8*X7+X1*X8*X6+X2*X3*
 181      & X7-X2*X4*X6-X2*X10*X6-X2*X6**2-X3*X10*X5-X3*X7*X5-X3*X6*
 182      & X5+X4*X6*X5)
 183       FM(2,5)=16*PQ**4*X10+8*PQ**2*(2*X1**2+2*X1*X3+2*X1*X4+2*X1
 184      & *X10+2*X1*X7+2*X1*X6+X3*X7+X4*X6)+8*(-2*X1**3-2*X1**2*X3-
 185      & 2*X1**2*X4-2*X1**2*X10-2*X1**2*X7-2*X1**2*X6-2*X1*X3*X4-
 186      & X1*X3*X10-2*X1*X3*X6-X1*X4*X10-2*X1*X4*X7-X1*X10**2-X1*
 187      & X10*X7-X1*X10*X6-2*X1*X7*X6+X3**2*X7-X3*X4*X7-X3*X4*X6+X3
 188      & *X10*X7+X3*X7**2-X3*X7*X6+X4**2*X6+X4*X10*X6-X4*X7*X6+X4*
 189      & X6**2)
 190       FM(2,6)=8*PQ**4*(-2*X1+X10-X9-2*X7)+4*PQ**2*(4*X1**2+2*X1*
 191      & X2+4*X1*X3+4*X1*X4+6*X1*X10-2*X1*X9+4*X1*X8+8*X1*X6-2*X1*
 192      & X5+4*X2*X4+3*X2*X10+2*X2*X7-3*X3*X9-2*X3*X7-4*X4**2-4*X4*
 193      & X10+3*X4*X8+2*X4*X6+X10*X5-X9*X6+3*X8*X7+4*X7*X6)+8*(X1**
 194      & 2*X9-X1**2*X8-X1*X2*X7+X1*X2*X6+X1*X3*X9+X1*X3*X5+X1*X4*
 195      & X9-X1*X4*X8-X1*X4*X5+X1*X10*X9+X1*X9*X6-X1*X8*X7-X2*X3*X7
 196      & -X2*X4*X7+X2*X4*X6-X2*X10*X7+X3*X7*X5-X4**2*X5-X4*X10*X5-
 197      & X4*X6*X5)
 198       FM(2,7)=8*PQ**4*(X3+2*X4+3*X10+X7+2*X6)+4*PQ**2*(-4*X1*X3-
 199      & 2*X1*X4-2*X1*X10+X1*X9-X1*X8-4*X1*X7-2*X1*X6+X2*X3+2*X2*
 200      & X4+3*X2*X10+X2*X7+2*X2*X6-6*X3*X4-6*X3*X10-2*X3*X9-2*X3*
 201      & X7-4*X3*X6-X3*X5-6*X4**2-6*X4*X10-3*X4*X9-X4*X8-4*X4*X7-2
 202      & *X4*X6-2*X4*X5-3*X10*X9-3*X10*X8-6*X10*X7-6*X10*X6+X10*X5
 203      & +X9*X7-2*X8*X7-2*X8*X6-6*X7*X6+X7*X5-6*X6**2+2*X6*X5)+4*(
 204      & -X1**2*X9+X1**2*X8-2*X1*X2*X10-3*X1*X2*X7-3*X1*X2*X6+X1*
 205      & X3*X9-X1*X3*X5+X1*X4*X9+X1*X4*X8+X1*X4*X5+X1*X10*X9+X1*
 206      & X10*X8-X1*X9*X6+X1*X8*X6+X2*X3*X7-3*X2*X4*X7-X2*X4*X6-3*
 207      & X2*X10*X7-3*X2*X10*X6-3*X2*X7*X6-3*X2*X6**2-2*X3*X4*X5-X3
 208      & *X10*X5-X3*X6*X5-X4**2*X5-X4*X10*X5+X4*X6*X5)
 209       FM(2,8)=8*PQ**4*(X3+2*X4+3*X10+X7+2*X6)+4*PQ**2*(-4*X1*X3-
 210      & 2*X1*X4-2*X1*X10-X1*X9+X1*X8-4*X1*X7-2*X1*X6+X2*X3+2*X2*
 211      & X4+X2*X10-X2*X7-2*X2*X6-6*X3*X4-6*X3*X10-2*X3*X9+X3*X8-2*
 212      & X3*X7-4*X3*X6+X3*X5-6*X4**2-6*X4*X10-2*X4*X9-4*X4*X7-2*X4
 213      & *X6+2*X4*X5-3*X10*X9-3*X10*X8-6*X10*X7-6*X10*X6+3*X10*X5-
 214      & X9*X6-2*X8*X7-3*X8*X6-6*X7*X6+X7*X5-6*X6**2+2*X6*X5)+4*(
 215      & X1**2*X9-X1**2*X8-X1*X2*X7+X1*X2*X6-3*X1*X3*X5+X1*X4*X9-
 216      & X1*X4*X8-3*X1*X4*X5+X1*X10*X9+X1*X10*X8-2*X1*X10*X5+X1*X9
 217      & *X6+X1*X8*X7+X1*X8*X6-X2*X4*X7+X2*X4*X6-X2*X10*X7-X2*X10*
 218      & X6-2*X2*X7*X6-X2*X6**2-3*X3*X4*X5-3*X3*X10*X5+X3*X7*X5-3*
 219      & X3*X6*X5-3*X4**2*X5-3*X4*X10*X5-X4*X6*X5)
 220       FM(3,3)=64*PQ**6+16*PQ**4*PH**2+32*PQ**4*(X1+X2+2*X3+X8+X6
 221      & +2*X5)+8*PQ**2*PH**2*(-X1+2*X3-X6)+16*PQ**2*(X2*X5-2*X3*
 222      & X8-2*X3*X6+4*X3*X5+X8*X5)+8*PH**2*X3*X6-16*X3*X8*X5
 223       FM(3,4)=16*PQ**4*(-4*X1-X3+X8-X6)+4*PQ**2*PH**2*(-2*X1-X3-
 224      & X6)+16*PQ**2*(-2*X1**2-3*X1*X2-2*X1*X3-3*X1*X8-2*X1*X6-3*
 225      & X1*X5-2*X2*X3-2*X6*X5)-8*PH**2*X3*X6+8*(-X1*X2*X8-2*X1*X2
 226      & *X5-X1*X8**2-X1*X8*X5+X2**2*X6-X2*X3*X5+X2*X8*X6-X2*X6*X5
 227      & +X3*X8*X5+X3*X5**2)
 228       FM(3,5)=8*PQ**4*(-2*X1+X10-X8-2*X6)+4*PQ**2*(4*X1**2+2*X1*
 229      & X2+4*X1*X3+4*X1*X4+6*X1*X10+4*X1*X9-2*X1*X8+8*X1*X7-2*X1*
 230      & X5+4*X2*X3+3*X2*X10+2*X2*X6-4*X3**2-4*X3*X10+3*X3*X9+2*X3
 231      & *X7-3*X4*X8-2*X4*X6+X10*X5+3*X9*X6-X8*X7+4*X7*X6)+8*(-X1
 232      & **2*X9+X1**2*X8+X1*X2*X7-X1*X2*X6-X1*X3*X9+X1*X3*X8-X1*X3
 233      & *X5+X1*X4*X8+X1*X4*X5+X1*X10*X8-X1*X9*X6+X1*X8*X7+X2*X3*
 234      & X7-X2*X3*X6-X2*X4*X6-X2*X10*X6-X3**2*X5-X3*X10*X5-X3*X7*
 235      & X5+X4*X6*X5)
 236       FM(3,6)=16*PQ**6+4*PQ**4*PH**2+16*PQ**4*(-X1-X2+2*X3+2*X4+
 237      & X10-X9-X8-X7-X6+X5)+4*PQ**2*PH**2*(X1+2*X3+2*X4+X10+X7+X6
 238      & )+8*PQ**2*(4*X1*X3+4*X1*X4+4*X1*X10+4*X2*X3+4*X2*X4+4*X2*
 239      & X10-X2*X5+4*X3*X5+4*X4*X5+2*X10*X5-X9*X5-X8*X5)-(8*PH**2*
 240      & X1)*(X3+X4+X10)+16*X2*X5*(X3+X4+X10)
 241       FM(3,7)=8*PQ**4*(3*X3+6*X4+3*X10+X9+2*X8+2*X7+X6)+2*PQ**2*
 242      & PH**2*(X3+2*X4+2*X10-2*X7-X6)+4*PQ**2*(4*X1*X3+8*X1*X4+4*
 243      & X1*X10+2*X1*X9-2*X1*X8+2*X2*X3+10*X2*X4+5*X2*X10+2*X2*X9+
 244      & X2*X8+2*X2*X7+4*X2*X6-7*X3*X9+2*X3*X8-8*X3*X7+4*X3*X6+4*
 245      & X3*X5+5*X4*X8+4*X4*X6+8*X4*X5+5*X10*X5-X9*X8-X9*X6+X9*X5+
 246      & X8**2-X8*X7+2*X8*X6+2*X8*X5)+2*PH**2*(-X1*X10+X3*X7-2*X3*
 247      & X6+X4*X6)+4*(-X1*X2*X9-2*X1*X2*X8+X1*X9*X8-X1*X8**2+X2**2
 248      & *X7+2*X2**2*X6+3*X2*X4*X5+2*X2*X10*X5-2*X2*X9*X6+X2*X8*X7
 249      & +X2*X8*X6-2*X3*X9*X5+X3*X8*X5+X4*X8*X5)
 250       FM(3,8)=8*PQ**4*(3*X3+6*X4+3*X10+2*X9+X8+2*X7+X6)+2*PQ**2*
 251      & PH**2*(3*X3+6*X4+3*X10-2*X7-X6)+4*PQ**2*(4*X1*X3+8*X1*X4+
 252      & 4*X1*X10+4*X2*X3+8*X2*X4+4*X2*X10-8*X3*X9+4*X3*X8-8*X3*X7
 253      & +4*X3*X6+6*X3*X5+4*X4*X8+4*X4*X6+12*X4*X5+6*X10*X5+2*X9*
 254      & X5+X8*X5)+4*PH**2*(-X1*X3-2*X1*X4-X1*X10+2*X3*X7-X3*X6-X4
 255      & *X6)+8*X5*(X2*X3+2*X2*X4+X2*X10-2*X3*X9+X3*X8+X4*X8)
 256       FM(4,4)=64*PQ**6+16*PQ**4*PH**2+32*PQ**4*(X1+2*X2+X3+X8+2*
 257      & X6+X5)+8*PQ**2*PH**2*(-X1-X3+2*X6)+16*PQ**2*(X2*X8+4*X2*
 258      & X6+X2*X5-2*X3*X6-2*X8*X6)+8*PH**2*X3*X6-16*X2*X8*X6
 259       FM(4,5)=16*PQ**6+8*PQ**4*(-2*X1+X2-2*X3-2*X4-4*X10-X9+X8-4
 260      & *X7+2*X6+X5)+8*PQ**2*(-2*X1*X2-2*X2*X3-2*X2*X10-2*X2*X7+
 261      & X2*X6+2*X3*X6-2*X4*X6+4*X10*X6-X9*X6-X8*X6)+16*X2*X6*(X3+
 262      & X10)
 263       FM(4,6)=16*PQ**6-4*PQ**4*PH**2+8*PQ**4*(-2*X1+2*X2-4*X3-2*
 264      & X4-8*X10+X9+X8-4*X7-2*X6+2*X5)-(4*PQ**2*PH**2)*(X1+X3+X10
 265      & +X7)+8*PQ**2*(-2*X1*X2-2*X1*X10+X1*X9+X1*X8-2*X1*X5+X2**2
 266      & -4*X2*X3-5*X2*X10+X2*X9-3*X2*X7-X2*X6+X2*X5+X3*X9+2*X3*X7
 267      & -3*X3*X5+X4*X8+2*X4*X6-X4*X5-5*X10*X5+X9*X8+X9*X6+X8*X7+
 268      & X8*X5-4*X7*X5+X5**2)-(16*X2*X5)*(X1+X3+X10+X7)
 269       FM(4,7)=8*PQ**4*(-X3-2*X4-3*X10-2*X9-X8-6*X7-3*X6)+2*PQ**2
 270      & *PH**2*(X3+2*X4-3*X10-6*X7-3*X6)+4*PQ**2*(-4*X1*X10-8*X1*
 271      & X7-4*X1*X6-6*X2*X10-2*X2*X9-X2*X8-12*X2*X7-6*X2*X6-4*X3*
 272      & X7-4*X3*X6+8*X4*X6-4*X10*X5+8*X9*X6-4*X8*X7-4*X8*X6-8*X7*
 273      & X5-4*X6*X5)+4*PH**2*(X1*X10+2*X1*X7+X1*X6+X3*X7+X3*X6-2*
 274      & X4*X6)+8*X2*(-X10*X5+2*X9*X6-X8*X7-X8*X6-2*X7*X5-X6*X5)
 275       FM(4,8)=8*PQ**4*(-X3-2*X4-3*X10-X9-2*X8-6*X7-3*X6)+2*PQ**2
 276      & *PH**2*(X3+2*X4-2*X10-2*X7-X6)+4*PQ**2*(-4*X1*X10-2*X1*X9
 277      & +2*X1*X8-8*X1*X7-4*X1*X6-5*X2*X10-X2*X9-2*X2*X8-8*X2*X7-4
 278      & *X2*X6+X3*X9-2*X3*X8-4*X3*X7-4*X3*X6-4*X3*X5+X4*X8+8*X4*
 279      & X6-2*X4*X5-5*X10*X5+X9*X8+7*X9*X6-2*X9*X5-X8**2-5*X8*X7-2
 280      & *X8*X6-X8*X5-10*X7*X5-2*X6*X5)+2*PH**2*(X1*X10-X3*X7+2*X3
 281      & *X6-X4*X6)+4*(-X1*X9*X8+X1*X9*X5+X1*X8**2+2*X1*X8*X5-2*X2
 282      & *X10*X5+2*X2*X9*X6-X2*X8*X7-X2*X8*X6-3*X2*X7*X5+2*X3*X9*
 283      & X5-X3*X8*X5-2*X3*X5**2-X4*X8*X5-X4*X5**2)
 284       FM(5,5)=16*PQ**6+16*PQ**4*(-X1-X3+X4-X10-X7+X6)+16*PQ**2*(
 285      & X3*X6+X4*X10+X4*X7+X4*X6+X10*X6)-16*X4*X10*X6
 286       FM(5,6)=16*PQ**6+8*PQ**4*(-2*X1+X2-4*X3+2*X4-4*X10+X9-X8-2
 287      & *X7-2*X6+X5)+8*PQ**2*(-2*X1*X5-2*X3*X5+4*X4*X10-X4*X9-X4*
 288      & X8+2*X4*X7-2*X4*X6+X4*X5-2*X10*X5-2*X7*X5)+16*X4*X5*(X10+
 289      & X7)
 290       FM(5,7)=8*PQ**4*(-2*X3-X4-3*X10-2*X7-X6)+4*PQ**2*(2*X1*X3+
 291      & 4*X1*X4+2*X1*X10+X1*X9-X1*X8+2*X1*X7+4*X1*X6-2*X2*X3-X2*
 292      & X4-3*X2*X10-2*X2*X7-X2*X6+6*X3**2+6*X3*X4+6*X3*X10+X3*X9+
 293      & 3*X3*X8+2*X3*X7+4*X3*X6+2*X3*X5+6*X4*X10+2*X4*X8+4*X4*X7+
 294      & 2*X4*X6+X4*X5+3*X10*X9+3*X10*X8+6*X10*X7+6*X10*X6-X10*X5+
 295      & 2*X9*X7+2*X9*X6-X8*X6+6*X7**2+6*X7*X6-2*X7*X5-X6*X5)+4*(-
 296      & X1**2*X9+X1**2*X8+2*X1*X2*X10+3*X1*X2*X7+3*X1*X2*X6-X1*X3
 297      & *X9-X1*X3*X8-X1*X3*X5-X1*X4*X8+X1*X4*X5-X1*X10*X9-X1*X10*
 298      & X8-X1*X9*X7+X1*X8*X7+X2*X3*X7+3*X2*X3*X6-X2*X4*X6+3*X2*
 299      & X10*X7+3*X2*X10*X6+3*X2*X7**2+3*X2*X7*X6+X3**2*X5+2*X3*X4
 300      & *X5+X3*X10*X5-X3*X7*X5+X4*X10*X5+X4*X7*X5)
 301       FM(5,8)=8*PQ**4*(-2*X3-X4-3*X10-2*X7-X6)+4*PQ**2*(2*X1*X3+
 302      & 4*X1*X4+2*X1*X10-X1*X9+X1*X8+2*X1*X7+4*X1*X6-2*X2*X3-X2*
 303      & X4-X2*X10+2*X2*X7+X2*X6+6*X3**2+6*X3*X4+6*X3*X10+2*X3*X8+
 304      & 2*X3*X7+4*X3*X6-2*X3*X5+6*X4*X10-X4*X9+2*X4*X8+4*X4*X7+2*
 305      & X4*X6-X4*X5+3*X10*X9+3*X10*X8+6*X10*X7+6*X10*X6-3*X10*X5+
 306      & 3*X9*X7+2*X9*X6+X8*X7+6*X7**2+6*X7*X6-2*X7*X5-X6*X5)+4*(
 307      & X1**2*X9-X1**2*X8-X1*X2*X7+X1*X2*X6+X1*X3*X9-X1*X3*X8+3*
 308      & X1*X3*X5+3*X1*X4*X5-X1*X10*X9-X1*X10*X8+2*X1*X10*X5-X1*X9
 309      & *X7-X1*X9*X6-X1*X8*X7-X2*X3*X7+X2*X3*X6+X2*X10*X7+X2*X10*
 310      & X6+X2*X7**2+2*X2*X7*X6+3*X3**2*X5+3*X3*X4*X5+3*X3*X10*X5+
 311      & X3*X7*X5+3*X4*X10*X5+3*X4*X7*X5-X4*X6*X5)
 312       FM(6,6)=64*PQ**6+16*PQ**4*PH**2+32*PQ**4*(X1+X2+2*X4+X9+X7
 313      & +2*X5)+8*PQ**2*PH**2*(-X1+2*X4-X7)+16*PQ**2*(X2*X5-2*X4*
 314      & X9-2*X4*X7+4*X4*X5+X9*X5)+8*PH**2*X4*X7-16*X4*X9*X5
 315       FM(6,7)=8*PQ**4*(-6*X3-3*X4-3*X10-2*X9-X8-X7-2*X6)+2*PQ**2
 316      & *PH**2*(-2*X3-X4-2*X10+X7+2*X6)+4*PQ**2*(-8*X1*X3-4*X1*X4
 317      & -4*X1*X10+2*X1*X9-2*X1*X8-10*X2*X3-2*X2*X4-5*X2*X10-X2*X9
 318      & -2*X2*X8-4*X2*X7-2*X2*X6-5*X3*X9-4*X3*X7-8*X3*X5-2*X4*X9+
 319      & 7*X4*X8-4*X4*X7+8*X4*X6-4*X4*X5-5*X10*X5-X9**2+X9*X8-2*X9
 320      & *X7+X9*X6-2*X9*X5+X8*X7-X8*X5)+2*PH**2*(X1*X10-X3*X7+2*X4
 321      & *X7-X4*X6)+4*(2*X1*X2*X9+X1*X2*X8+X1*X9**2-X1*X9*X8-2*X2
 322      & **2*X7-X2**2*X6-3*X2*X3*X5-2*X2*X10*X5-X2*X9*X7-X2*X9*X6+
 323      & 2*X2*X8*X7-X3*X9*X5-X4*X9*X5+2*X4*X8*X5)
 324       FM(6,8)=8*PQ**4*(-6*X3-3*X4-3*X10-X9-2*X8-X7-2*X6)+2*PQ**2
 325      & *PH**2*(-6*X3-3*X4-3*X10+X7+2*X6)+4*PQ**2*(-8*X1*X3-4*X1*
 326      & X4-4*X1*X10-8*X2*X3-4*X2*X4-4*X2*X10-4*X3*X9-4*X3*X7-12*
 327      & X3*X5-4*X4*X9+8*X4*X8-4*X4*X7+8*X4*X6-6*X4*X5-6*X10*X5-X9
 328      & *X5-2*X8*X5)+4*PH**2*(2*X1*X3+X1*X4+X1*X10+X3*X7+X4*X7-2*
 329      & X4*X6)+8*X5*(-2*X2*X3-X2*X4-X2*X10-X3*X9-X4*X9+2*X4*X8)
 330       FM(7,7)=72*PQ**4*X10+18*PQ**2*PH**2*X10+8*PQ**2*(X1*X10+9*
 331      & X2*X10+7*X3*X7+2*X3*X6+2*X4*X7+7*X4*X6+X10*X5+2*X9*X7+7*
 332      & X9*X6+7*X8*X7+2*X8*X6)+2*PH**2*(-X1*X10-7*X3*X7-2*X3*X6-2
 333      & *X4*X7-7*X4*X6)+4*X2*(X10*X5+2*X9*X7+7*X9*X6+7*X8*X7+2*X8
 334      & *X6)
 335       FM(7,8)=72*PQ**4*X10+2*PQ**2*PH**2*X10+4*PQ**2*(2*X1*X10+
 336      & 10*X2*X10+7*X3*X9+2*X3*X8+14*X3*X7+4*X3*X6+2*X4*X9+7*X4*
 337      & X8+4*X4*X7+14*X4*X6+10*X10*X5+X9**2+7*X9*X8+2*X9*X7+7*X9*
 338      & X6+X8**2+7*X8*X7+2*X8*X6)+2*PH**2*(7*X1*X10-7*X3*X7-2*X3*
 339      & X6-2*X4*X7-7*X4*X6)+2*(-2*X1*X9**2-14*X1*X9*X8-2*X1*X8**2
 340      & +2*X2*X10*X5+2*X2*X9*X7+7*X2*X9*X6+7*X2*X8*X7+2*X2*X8*X6+
 341      & 7*X3*X9*X5+2*X3*X8*X5+2*X4*X9*X5+7*X4*X8*X5)
 342       FM(8,8)=72*PQ**4*X10+18*PQ**2*PH**2*X10+8*PQ**2*(X1*X10+X2
 343      & *X10+7*X3*X9+2*X3*X8+7*X3*X7+2*X3*X6+2*X4*X9+7*X4*X8+2*X4
 344      & *X7+7*X4*X6+9*X10*X5)+2*PH**2*(-X1*X10-7*X3*X7-2*X3*X6-2*
 345      & X4*X7-7*X4*X6)+4*X5*(X2*X10+7*X3*X9+2*X3*X8+2*X4*X9+7*X4*
 346      & X8)
 347       FM(9,9)=-4*PQ**4*X10-PQ**2*PH**2*X10+4*PQ**2*(-X1*X10-X2*X10+
 348      & X3*X7+X4*X6-X10*X5+X9*X6+X8*X7)+PH**2*(X1*X10-X3*X7-X4*X6
 349      & )+2*X2*(-X10*X5+X9*X6+X8*X7)
 350       FM(9,10)=-4*PQ**4*X10-PQ**2*PH**2*X10+2*PQ**2*(-2*X1*X10-2*X2*
 351      & X10+2*X3*X9+2*X3*X7+2*X4*X6-2*X10*X5+X9*X8+2*X8*X7)+PH**2
 352      & *(X1*X10-X3*X7-X4*X6)+2*(-X1*X9*X8-X2*X10*X5+X2*X8*X7+X3*
 353      & X9*X5)
 354       FMXX=-4*PQ**4*X10-PQ**2*PH**2*X10+2*PQ**2*(-2*X1*X10-2*X2*
 355      & X10+2*X4*X8+2*X4*X6+2*X3*X7-2*X10*X5+X9*X8+2*X9*X6)+PH**2
 356      & *(X1*X10-X3*X7-X4*X6)+2*(-X1*X9*X8-X2*X10*X5+X2*X9*X6+X4*
 357      & X8*X5)
 358       FM(9,10)=0.5*(FMXX+FM(9,10))
 359       FM(10,10)=-4*PQ**4*X10-PQ**2*PH**2*X10+4*PQ**2*(-X1*X10-X2*X10+
 360      & X3*X7+X4*X6-X10*X5+X9*X3+X8*X4)+PH**2*(X1*X10-X3*X7-X4*X6
 361      & )+2*X5*(-X10*X2+X9*X3+X8*X4)
 362
 363 C...Repackage matrix elements.
 364         DO 200 I=1,8
 365         DO 190 J=1,8
 366         RM(I,J)=FM(I,J)
 367   190   CONTINUE
 368   200   CONTINUE
 369         RM(7,7)=FM(7,7)-2.*FM(9,9)
 370         RM(7,8)=FM(7,8)-2.*FM(9,10)
 371         RM(8,8)=FM(8,8)-2.*FM(10,10)
 372
 373 C...Produce final result: matrix elements * colours * propagators.
 374         DO 220 I=1,8
 375         DO 210 J=I,8
 376         FAC=8.
 377         IF(I.EQ.J)FAC=4.
 378         WTQQBH=WTQQBH+RM(I,J)*FAC*CLR(I,J)/(DX(I)*DX(J))
 379   210   CONTINUE
 380   220   CONTINUE
 381         WTQQBH=-WTQQBH/256.
 382
 383       ELSE
 384 C...Evaluate matrix elements for q + q~ -> Q + Q~ + H.
 385         A11=-8.*PQ**4*X10-2.*PQ**2*PH**2*X10-(8.*PQ**2)*(X2*X10+X3
 386      &   *X7+X4*X6+X9*X6+X8*X7)+2.*PH**2*(X3*X7+X4*X6)-(4.*X2)*(X9
 387      &   *X6+X8*X7)
 388         A12=-8.*PQ**4*X10+4.*PQ**2*(-X2*X10-X3*X9-2.*X3*X7-X4*X8-
 389      &   2.*X4*X6-X10*X5-X9*X8-X9*X6-X8*X7)+2.*PH**2*(-X1*X10+X3*X7
 390      &   +X4*X6)+2.*(2.*X1*X9*X8-X2*X9*X6-X2*X8*X7-X3*X9*X5-X4*X8*
 391      &   X5)
 392         A22=-8.*PQ**4*X10-2.*PQ**2*PH**2*X10-(8.*PQ**2)*(X3*X9+X3*
 393      &   X7+X4*X8+X4*X6+X10*X5)+2.*PH**2*(X3*X7+X4*X6)-(4.*X5)*(X3
 394      &   *X9+X4*X8)
 395
 396 C...Produce final result: matrix elements * propagators.
 397         A11=A11/DX(7)**2
 398         A12=A12/(DX(7)*DX(8))
 399         A22=A22/DX(8)**2
 400         WTQQBH=-(A11+A22+2.*A12)/8.
 401       ENDIF
 402
 403       RETURN
 404       END