Additional protection (macosx with gfortran)
[u/mrichter/AliRoot.git] / HIJING / hipyset1_35 / pysigh_hijing.F
CommitLineData
e74335a4 1* $Id$
2
3C***********************************************************************
4
5 SUBROUTINE PYSIGH_HIJING(NCHN,SIGS)
6
7C...Differential matrix elements for all included subprocesses.
8C...Note that what is coded is (disregarding the COMFAC factor)
9C...1) for 2 -> 1 processes: s-hat/pi*d(sigma-hat), where,
10C...when d(sigma-hat) is given in the zero-width limit, the delta
11C...function in tau is replaced by a Breit-Wigner:
12C...1/pi*(s*m_res*Gamma_res)/((s*tau-m_res^2)^2+(m_res*Gamma_res)^2);
13C...2) for 2 -> 2 processes: (s-hat)**2/pi*d(sigma-hat)/d(t-hat);
14C...i.e., dimensionless quantities. COMFAC contains the factor
15C...pi/s and the conversion factor from GeV^-2 to mb.
16#include "ludat1_hijing.inc"
17#include "ludat2_hijing.inc"
18#include "ludat3_hijing.inc"
19#include "pysubs_hijing.inc"
20#include "pypars_hijing.inc"
21#include "pyint1_hijing.inc"
22#include "pyint2_hijing.inc"
23#include "pyint3_hijing.inc"
24#include "pyint4_hijing.inc"
25#include "pyint5_hijing.inc"
26 DIMENSION X(2),XPQ(-6:6),KFAC(2,-40:40),WDTP(0:40),WDTE(0:40,0:5)
27
28C...Reset number of channels and cross-section.
29 NCHN=0
30 SIGS=0.
31
32C...Read kinematical variables and limits.
33 ISUB=MINT(1)
34 TAUMIN=VINT(11)
35 YSTMIN=VINT(12)
36 CTNMIN=VINT(13)
37 CTPMIN=VINT(14)
38 XT2MIN=VINT(15)
39 TAUPMN=VINT(16)
40 TAU=VINT(21)
41 YST=VINT(22)
42 CTH=VINT(23)
43 XT2=VINT(25)
44 TAUP=VINT(26)
45 TAUMAX=VINT(31)
46 YSTMAX=VINT(32)
47 CTNMAX=VINT(33)
48 CTPMAX=VINT(34)
49 XT2MAX=VINT(35)
50 TAUPMX=VINT(36)
51
52C...Derive kinematical quantities.
53 IF(ISET(ISUB).LE.2.OR.ISET(ISUB).EQ.5) THEN
54 X(1)=SQRT(TAU)*EXP(YST)
55 X(2)=SQRT(TAU)*EXP(-YST)
56 ELSE
57 X(1)=SQRT(TAUP)*EXP(YST)
58 X(2)=SQRT(TAUP)*EXP(-YST)
59 ENDIF
60 IF(MINT(43).EQ.4.AND.ISET(ISUB).GE.1.AND.
61 &(X(1).GT.0.999.OR.X(2).GT.0.999)) RETURN
62 SH=TAU*VINT(2)
63 SQM3=VINT(63)
64 SQM4=VINT(64)
65 RM3=SQM3/SH
66 RM4=SQM4/SH
67 BE34=SQRT((1.-RM3-RM4)**2-4.*RM3*RM4)
68 RPTS=4.*VINT(71)**2/SH
69 BE34L=SQRT(MAX(0.,(1.-RM3-RM4)**2-4.*RM3*RM4-RPTS))
70 RM34=2.*RM3*RM4
71 RSQM=1.+RM34
72 RTHM=(4.*RM3*RM4+RPTS)/(1.-RM3-RM4+BE34L)
73 TH=-0.5*SH*MAX(RTHM,1.-RM3-RM4-BE34*CTH)
74 UH=-0.5*SH*MAX(RTHM,1.-RM3-RM4+BE34*CTH)
75 SQPTH=0.25*SH*BE34**2*(1.-CTH**2)
76 SH2=SH**2
77 TH2=TH**2
78 UH2=UH**2
79
80C...Choice of Q2 scale.
81 IF(ISET(ISUB).EQ.1.OR.ISET(ISUB).EQ.3) THEN
82 Q2=SH
83 ELSEIF(MOD(ISET(ISUB),2).EQ.0.OR.ISET(ISUB).EQ.5) THEN
84 IF(MSTP(32).EQ.1) THEN
85 Q2=2.*SH*TH*UH/(SH**2+TH**2+UH**2)
86 ELSEIF(MSTP(32).EQ.2) THEN
87 Q2=SQPTH+0.5*(SQM3+SQM4)
88 ELSEIF(MSTP(32).EQ.3) THEN
89 Q2=MIN(-TH,-UH)
90 ELSEIF(MSTP(32).EQ.4) THEN
91 Q2=SH
92 ENDIF
93 IF(ISET(ISUB).EQ.5.AND.MSTP(82).GE.2) Q2=Q2+PARP(82)**2
94 ENDIF
95
96C...Store derived kinematical quantities.
97 VINT(41)=X(1)
98 VINT(42)=X(2)
99 VINT(44)=SH
100 VINT(43)=SQRT(SH)
101 VINT(45)=TH
102 VINT(46)=UH
103 VINT(48)=SQPTH
104 VINT(47)=SQRT(SQPTH)
105 VINT(50)=TAUP*VINT(2)
106 VINT(49)=SQRT(MAX(0.,VINT(50)))
107 VINT(52)=Q2
108 VINT(51)=SQRT(Q2)
109
110C...Calculate parton structure functions.
111 IF(ISET(ISUB).LE.0) GOTO 145
112 IF(MINT(43).GE.2) THEN
113 Q2SF=Q2
114 IF(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4) THEN
115 Q2SF=PMAS(23,1)**2
116 IF(ISUB.EQ.8.OR.ISUB.EQ.76.OR.ISUB.EQ.77) Q2SF=PMAS(24,1)**2
117 ENDIF
118 DO 100 I=3-MINT(41),MINT(42)
119 XSF=X(I)
120 IF(ISET(ISUB).EQ.5) XSF=X(I)/VINT(142+I)
121 CALL PYSTFU_HIJING(MINT(10+I),XSF,Q2SF,XPQ,I)
122 DO 100 KFL=-6,6
123 100 XSFX(I,KFL)=XPQ(KFL)
124 ENDIF
125
126C...Calculate alpha_strong and K-factor.
127 IF(MSTP(33).NE.3) AS=ULALPS_HIJING(Q2)
128 FACK=1.
129 FACA=1.
130 IF(MSTP(33).EQ.1) THEN
131 FACK=PARP(31)
132 ELSEIF(MSTP(33).EQ.2) THEN
133 FACK=PARP(31)
134 FACA=PARP(32)/PARP(31)
135 ELSEIF(MSTP(33).EQ.3) THEN
136 Q2AS=PARP(33)*Q2
137 IF(ISET(ISUB).EQ.5.AND.MSTP(82).GE.2) Q2AS=Q2AS+
138 & PARU(112)*PARP(82)
139 AS=ULALPS_HIJING(Q2AS)
140 ENDIF
141 RADC=1.+AS/PARU(1)
142
143C...Set flags for allowed reacting partons/leptons.
144 DO 130 I=1,2
145 DO 110 J=-40,40
146 110 KFAC(I,J)=0
147 IF(MINT(40+I).EQ.1) THEN
148 KFAC(I,MINT(10+I))=1
149 ELSE
150 DO 120 J=-40,40
151 KFAC(I,J)=KFIN(I,J)
152 IF(ABS(J).GT.MSTP(54).AND.J.NE.21) KFAC(I,J)=0
153 IF(ABS(J).LE.6) THEN
154 IF(XSFX(I,J).LT.1.E-10) KFAC(I,J)=0
155 ELSEIF(J.EQ.21) THEN
156 IF(XSFX(I,0).LT.1.E-10) KFAC(I,21)=0
157 ENDIF
158 120 CONTINUE
159 ENDIF
160 130 CONTINUE
161
162C...Lower and upper limit for flavour loops.
163 MIN1=0
164 MAX1=0
165 MIN2=0
166 MAX2=0
167 DO 140 J=-20,20
168 IF(KFAC(1,-J).EQ.1) MIN1=-J
169 IF(KFAC(1,J).EQ.1) MAX1=J
170 IF(KFAC(2,-J).EQ.1) MIN2=-J
171 IF(KFAC(2,J).EQ.1) MAX2=J
172 140 CONTINUE
173 MINA=MIN(MIN1,MIN2)
174 MAXA=MAX(MAX1,MAX2)
175
176C...Common conversion factors (including Jacobian) for subprocesses.
177 SQMZ=PMAS(23,1)**2
178 GMMZ=PMAS(23,1)*PMAS(23,2)
179 SQMW=PMAS(24,1)**2
180 GMMW=PMAS(24,1)*PMAS(24,2)
181 SQMH=PMAS(25,1)**2
182 GMMH=PMAS(25,1)*PMAS(25,2)
183 SQMZP=PMAS(32,1)**2
184 GMMZP=PMAS(32,1)*PMAS(32,2)
185 SQMHC=PMAS(37,1)**2
186 GMMHC=PMAS(37,1)*PMAS(37,2)
187 SQMR=PMAS(40,1)**2
188 GMMR=PMAS(40,1)*PMAS(40,2)
189 AEM=PARU(101)
190 XW=PARU(102)
191
192C...Phase space integral in tau and y*.
193 COMFAC=PARU(1)*PARU(5)/VINT(2)
194 IF(MINT(43).EQ.4) COMFAC=COMFAC*FACK
195 IF((MINT(43).GE.2.OR.ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4).AND.
196 &ISET(ISUB).NE.5) THEN
197 ATAU0=LOG(TAUMAX/TAUMIN)
198 ATAU1=(TAUMAX-TAUMIN)/(TAUMAX*TAUMIN)
199 H1=COEF(ISUB,1)+(ATAU0/ATAU1)*COEF(ISUB,2)/TAU
200 IF(MINT(72).GE.1) THEN
201 TAUR1=VINT(73)
202 GAMR1=VINT(74)
203 ATAU2=LOG(TAUMAX/TAUMIN*(TAUMIN+TAUR1)/(TAUMAX+TAUR1))/TAUR1
204 ATAU3=(ATAN((TAUMAX-TAUR1)/GAMR1)-ATAN((TAUMIN-TAUR1)/GAMR1))/
205 & GAMR1
206 H1=H1+(ATAU0/ATAU2)*COEF(ISUB,3)/(TAU+TAUR1)+
207 & (ATAU0/ATAU3)*COEF(ISUB,4)*TAU/((TAU-TAUR1)**2+GAMR1**2)
208 ENDIF
209 IF(MINT(72).EQ.2) THEN
210 TAUR2=VINT(75)
211 GAMR2=VINT(76)
212 ATAU4=LOG(TAUMAX/TAUMIN*(TAUMIN+TAUR2)/(TAUMAX+TAUR2))/TAUR2
213 ATAU5=(ATAN((TAUMAX-TAUR2)/GAMR2)-ATAN((TAUMIN-TAUR2)/GAMR2))/
214 & GAMR2
215 H1=H1+(ATAU0/ATAU4)*COEF(ISUB,5)/(TAU+TAUR2)+
216 & (ATAU0/ATAU5)*COEF(ISUB,6)*TAU/((TAU-TAUR2)**2+GAMR2**2)
217 ENDIF
218 COMFAC=COMFAC*ATAU0/(TAU*H1)
219 ENDIF
220 IF(MINT(43).EQ.4.AND.ISET(ISUB).NE.5) THEN
221 AYST0=YSTMAX-YSTMIN
222 AYST1=0.5*(YSTMAX-YSTMIN)**2
223 AYST2=AYST1
224 AYST3=2.*(ATAN(EXP(YSTMAX))-ATAN(EXP(YSTMIN)))
225 H2=(AYST0/AYST1)*COEF(ISUB,7)*(YST-YSTMIN)+(AYST0/AYST2)*
226 & COEF(ISUB,8)*(YSTMAX-YST)+(AYST0/AYST3)*COEF(ISUB,9)/COSH(YST)
227 COMFAC=COMFAC*AYST0/H2
228 ENDIF
229
230C...2 -> 1 processes: reduction in angular part of phase space integral
231C...for case of decaying resonance.
232 ACTH0=CTNMAX-CTNMIN+CTPMAX-CTPMIN
3bc18c05 233 IF((ISET(ISUB).EQ.1.OR.ISET(ISUB).EQ.3)) THEN
234 IF( KFPR(ISUB,1).GT.0) THEN
235 IF (MDCY(KFPR(ISUB,1),1).EQ.1) THEN
236 IF(KFPR(ISUB,1).EQ.25.OR.KFPR(ISUB,1).EQ.37) THEN
237 COMFAC=COMFAC*0.5*ACTH0
238 ELSE
239 COMFAC=COMFAC*0.125*(3.*ACTH0+CTNMAX**3-CTNMIN**3+
240 & CTPMAX**3-CTPMIN**3)
241 ENDIF
242 ENDIF
243 ENDIF
e74335a4 244
245C...2 -> 2 processes: angular part of phase space integral.
246 ELSEIF(ISET(ISUB).EQ.2.OR.ISET(ISUB).EQ.4) THEN
247 ACTH1=LOG((MAX(RM34,RSQM-CTNMIN)*MAX(RM34,RSQM-CTPMIN))/
248 & (MAX(RM34,RSQM-CTNMAX)*MAX(RM34,RSQM-CTPMAX)))
249 ACTH2=LOG((MAX(RM34,RSQM+CTNMAX)*MAX(RM34,RSQM+CTPMAX))/
250 & (MAX(RM34,RSQM+CTNMIN)*MAX(RM34,RSQM+CTPMIN)))
251 ACTH3=1./MAX(RM34,RSQM-CTNMAX)-1./MAX(RM34,RSQM-CTNMIN)+
252 & 1./MAX(RM34,RSQM-CTPMAX)-1./MAX(RM34,RSQM-CTPMIN)
253 ACTH4=1./MAX(RM34,RSQM+CTNMIN)-1./MAX(RM34,RSQM+CTNMAX)+
254 & 1./MAX(RM34,RSQM+CTPMIN)-1./MAX(RM34,RSQM+CTPMAX)
255 H3=COEF(ISUB,10)+
256 & (ACTH0/ACTH1)*COEF(ISUB,11)/MAX(RM34,RSQM-CTH)+
257 & (ACTH0/ACTH2)*COEF(ISUB,12)/MAX(RM34,RSQM+CTH)+
258 & (ACTH0/ACTH3)*COEF(ISUB,13)/MAX(RM34,RSQM-CTH)**2+
259 & (ACTH0/ACTH4)*COEF(ISUB,14)/MAX(RM34,RSQM+CTH)**2
260 COMFAC=COMFAC*ACTH0*0.5*BE34/H3
261 ENDIF
262
263C...2 -> 3, 4 processes: phace space integral in tau'.
264 IF(MINT(43).GE.2.AND.(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4)) THEN
265 ATAUP0=LOG(TAUPMX/TAUPMN)
266 ATAUP1=((1.-TAU/TAUPMX)**4-(1.-TAU/TAUPMN)**4)/(4.*TAU)
267 H4=COEF(ISUB,15)+
268 & ATAUP0/ATAUP1*COEF(ISUB,16)/TAUP*(1.-TAU/TAUP)**3
269 IF(1.-TAU/TAUP.GT.1.E-4) THEN
270 FZW=(1.+TAU/TAUP)*LOG(TAUP/TAU)-2.*(1.-TAU/TAUP)
271 ELSE
272 FZW=1./6.*(1.-TAU/TAUP)**3*TAU/TAUP
273 ENDIF
274 COMFAC=COMFAC*ATAUP0*FZW/H4
275 ENDIF
276
277C...Phase space integral for low-pT and multiple interactions.
278 IF(ISET(ISUB).EQ.5) THEN
279 COMFAC=PARU(1)*PARU(5)*FACK*0.5*VINT(2)/SH2
280 ATAU0=LOG(2.*(1.+SQRT(1.-XT2))/XT2-1.)
281 ATAU1=2.*ATAN(1./XT2-1.)/SQRT(XT2)
282 H1=COEF(ISUB,1)+(ATAU0/ATAU1)*COEF(ISUB,2)/SQRT(TAU)
283 COMFAC=COMFAC*ATAU0/H1
284 AYST0=YSTMAX-YSTMIN
285 AYST1=0.5*(YSTMAX-YSTMIN)**2
286 AYST3=2.*(ATAN(EXP(YSTMAX))-ATAN(EXP(YSTMIN)))
287 H2=(AYST0/AYST1)*COEF(ISUB,7)*(YST-YSTMIN)+(AYST0/AYST1)*
288 & COEF(ISUB,8)*(YSTMAX-YST)+(AYST0/AYST3)*COEF(ISUB,9)/COSH(YST)
289 COMFAC=COMFAC*AYST0/H2
290 IF(MSTP(82).LE.1) COMFAC=COMFAC*XT2**2*(1./VINT(149)-1.)
291C...For MSTP(82)>=2 an additional factor (xT2/(xT2+VINT(149))**2 is
292C...introduced to make cross-section finite for xT2 -> 0.
293 IF(MSTP(82).GE.2) COMFAC=COMFAC*XT2**2/(VINT(149)*
294 & (1.+VINT(149)))
295 ENDIF
296
297C...A: 2 -> 1, tree diagrams.
298
299 145 IF(ISUB.LE.10) THEN
300 IF(ISUB.EQ.1) THEN
301C...f + fb -> gamma*/Z0.
302 MINT(61)=2
303 CALL PYWIDT_HIJING(23,SQRT(SH),WDTP,WDTE)
304 FACZ=COMFAC*AEM**2*4./3.
305 DO 150 I=MINA,MAXA
306 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 150
307 EI=KCHG(IABS(I),1)/3.
308 AI=SIGN(1.,EI)
309 VI=AI-4.*EI*XW
310 FACF=1.
311 IF(IABS(I).LE.10) FACF=FACA/3.
312 NCHN=NCHN+1
313 ISIG(NCHN,1)=I
314 ISIG(NCHN,2)=-I
315 ISIG(NCHN,3)=1
316 SIGH(NCHN)=FACF*FACZ*(EI**2*VINT(111)+EI*VI/(8.*XW*(1.-XW))*
317 & SH*(SH-SQMZ)/((SH-SQMZ)**2+GMMZ**2)*VINT(112)+(VI**2+AI**2)/
318 & (16.*XW*(1.-XW))**2*SH2/((SH-SQMZ)**2+GMMZ**2)*VINT(114))
319 150 CONTINUE
320
321 ELSEIF(ISUB.EQ.2) THEN
322C...f + fb' -> W+/-.
323 CALL PYWIDT_HIJING(24,SQRT(SH),WDTP,WDTE)
324 FACW=COMFAC*(AEM/XW)**2*1./24*SH2/((SH-SQMW)**2+GMMW**2)
325 DO 170 I=MIN1,MAX1
326 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 170
327 IA=IABS(I)
328 DO 160 J=MIN2,MAX2
329 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 160
330 JA=IABS(J)
331 IF(I*J.GT.0.OR.MOD(IA+JA,2).EQ.0) GOTO 160
332 IF((IA.LE.10.AND.JA.GT.10).OR.(IA.GT.10.AND.JA.LE.10)) GOTO 160
333 KCHW=(KCHG(IA,1)*ISIGN(1,I)+KCHG(JA,1)*ISIGN(1,J))/3
334 FACF=1.
335 IF(IA.LE.10) FACF=VCKM((IA+1)/2,(JA+1)/2)*FACA/3.
336 NCHN=NCHN+1
337 ISIG(NCHN,1)=I
338 ISIG(NCHN,2)=J
339 ISIG(NCHN,3)=1
340 SIGH(NCHN)=FACF*FACW*(WDTE(0,1)+WDTE(0,(5-KCHW)/2)+WDTE(0,4))
341 160 CONTINUE
342 170 CONTINUE
343
344 ELSEIF(ISUB.EQ.3) THEN
345C...f + fb -> H0.
346 CALL PYWIDT_HIJING(25,SQRT(SH),WDTP,WDTE)
347 FACH=COMFAC*(AEM/XW)**2*1./48.*(SH/SQMW)**2*
348 & SH2/((SH-SQMH)**2+GMMH**2)*(WDTE(0,1)+WDTE(0,2)+WDTE(0,4))
349 DO 180 I=MINA,MAXA
350 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 180
351 RMQ=PMAS(IABS(I),1)**2/SH
352 NCHN=NCHN+1
353 ISIG(NCHN,1)=I
354 ISIG(NCHN,2)=-I
355 ISIG(NCHN,3)=1
356 SIGH(NCHN)=FACH*RMQ*SQRT(MAX(0.,1.-4.*RMQ))
357 180 CONTINUE
358
359 ELSEIF(ISUB.EQ.4) THEN
360C...gamma + W+/- -> W+/-.
361
362 ELSEIF(ISUB.EQ.5) THEN
363C...Z0 + Z0 -> H0.
364 CALL PYWIDT_HIJING(25,SQRT(SH),WDTP,WDTE)
365 FACH=COMFAC*1./(128.*PARU(1)**2*16.*(1.-XW)**3)*(AEM/XW)**4*
366 & (SH/SQMW)**2*SH2/((SH-SQMH)**2+GMMH**2)*
367 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,4))
368 DO 200 I=MIN1,MAX1
369 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 200
370 DO 190 J=MIN2,MAX2
371 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 190
372 EI=KCHG(IABS(I),1)/3.
373 AI=SIGN(1.,EI)
374 VI=AI-4.*EI*XW
375 EJ=KCHG(IABS(J),1)/3.
376 AJ=SIGN(1.,EJ)
377 VJ=AJ-4.*EJ*XW
378 NCHN=NCHN+1
379 ISIG(NCHN,1)=I
380 ISIG(NCHN,2)=J
381 ISIG(NCHN,3)=1
382 SIGH(NCHN)=FACH*(VI**2+AI**2)*(VJ**2+AJ**2)
383 190 CONTINUE
384 200 CONTINUE
385
386 ELSEIF(ISUB.EQ.6) THEN
387C...Z0 + W+/- -> W+/-.
388
389 ELSEIF(ISUB.EQ.7) THEN
390C...W+ + W- -> Z0.
391
392 ELSEIF(ISUB.EQ.8) THEN
393C...W+ + W- -> H0.
394 CALL PYWIDT_HIJING(25,SQRT(SH),WDTP,WDTE)
395 FACH=COMFAC*1./(128*PARU(1)**2)*(AEM/XW)**4*(SH/SQMW)**2*
396 & SH2/((SH-SQMH)**2+GMMH**2)*(WDTE(0,1)+WDTE(0,2)+WDTE(0,4))
397 DO 220 I=MIN1,MAX1
398 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 220
399 EI=SIGN(1.,FLOAT(I))*KCHG(IABS(I),1)
400 DO 210 J=MIN2,MAX2
401 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 210
402 EJ=SIGN(1.,FLOAT(J))*KCHG(IABS(J),1)
403 IF(EI*EJ.GT.0.) GOTO 210
404 NCHN=NCHN+1
405 ISIG(NCHN,1)=I
406 ISIG(NCHN,2)=J
407 ISIG(NCHN,3)=1
408 SIGH(NCHN)=FACH*VINT(180+I)*VINT(180+J)
409 210 CONTINUE
410 220 CONTINUE
411 ENDIF
412
413C...B: 2 -> 2, tree diagrams.
414
415 ELSEIF(ISUB.LE.20) THEN
416 IF(ISUB.EQ.11) THEN
417C...f + f' -> f + f'.
418 FACQQ1=COMFAC*AS**2*4./9.*(SH2+UH2)/TH2
419 FACQQB=COMFAC*AS**2*4./9.*((SH2+UH2)/TH2*FACA-
420 & MSTP(34)*2./3.*UH2/(SH*TH))
421 FACQQ2=COMFAC*AS**2*4./9.*((SH2+TH2)/UH2-
422 & MSTP(34)*2./3.*SH2/(TH*UH))
423 DO 240 I=MIN1,MAX1
424 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 240
425 DO 230 J=MIN2,MAX2
426 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 230
427 NCHN=NCHN+1
428 ISIG(NCHN,1)=I
429 ISIG(NCHN,2)=J
430 ISIG(NCHN,3)=1
431 SIGH(NCHN)=FACQQ1
432 IF(I.EQ.-J) SIGH(NCHN)=FACQQB
433 IF(I.EQ.J) THEN
434 SIGH(NCHN)=0.5*SIGH(NCHN)
435 NCHN=NCHN+1
436 ISIG(NCHN,1)=I
437 ISIG(NCHN,2)=J
438 ISIG(NCHN,3)=2
439 SIGH(NCHN)=0.5*FACQQ2
440 ENDIF
441 230 CONTINUE
442 240 CONTINUE
443
444 ELSEIF(ISUB.EQ.12) THEN
445C...f + fb -> f' + fb' (q + qb -> q' + qb' only).
446 CALL PYWIDT_HIJING(21,SQRT(SH),WDTP,WDTE)
447 FACQQB=COMFAC*AS**2*4./9.*(TH2+UH2)/SH2*(WDTE(0,1)+WDTE(0,2)+
448 & WDTE(0,3)+WDTE(0,4))
449 DO 250 I=MINA,MAXA
450 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 250
451 NCHN=NCHN+1
452 ISIG(NCHN,1)=I
453 ISIG(NCHN,2)=-I
454 ISIG(NCHN,3)=1
455 SIGH(NCHN)=FACQQB
456 250 CONTINUE
457
458 ELSEIF(ISUB.EQ.13) THEN
459C...f + fb -> g + g (q + qb -> g + g only).
460 FACGG1=COMFAC*AS**2*32./27.*(UH/TH-(2.+MSTP(34)*1./4.)*UH2/SH2)
461 FACGG2=COMFAC*AS**2*32./27.*(TH/UH-(2.+MSTP(34)*1./4.)*TH2/SH2)
462 DO 260 I=MINA,MAXA
463 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 260
464 NCHN=NCHN+1
465 ISIG(NCHN,1)=I
466 ISIG(NCHN,2)=-I
467 ISIG(NCHN,3)=1
468 SIGH(NCHN)=0.5*FACGG1
469 NCHN=NCHN+1
470 ISIG(NCHN,1)=I
471 ISIG(NCHN,2)=-I
472 ISIG(NCHN,3)=2
473 SIGH(NCHN)=0.5*FACGG2
474 260 CONTINUE
475
476 ELSEIF(ISUB.EQ.14) THEN
477C...f + fb -> g + gamma (q + qb -> g + gamma only).
478 FACGG=COMFAC*AS*AEM*8./9.*(TH2+UH2)/(TH*UH)
479 DO 270 I=MINA,MAXA
480 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 270
481 EI=KCHG(IABS(I),1)/3.
482 NCHN=NCHN+1
483 ISIG(NCHN,1)=I
484 ISIG(NCHN,2)=-I
485 ISIG(NCHN,3)=1
486 SIGH(NCHN)=FACGG*EI**2
487 270 CONTINUE
488
489 ELSEIF(ISUB.EQ.15) THEN
490C...f + fb -> g + Z0 (q + qb -> g + Z0 only).
491 FACZG=COMFAC*AS*AEM/(XW*(1.-XW))*1./18.*
492 & (TH2+UH2+2.*SQM4*SH)/(TH*UH)
493 FACZG=FACZG*WIDS(23,2)
494 DO 280 I=MINA,MAXA
495 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 280
496 EI=KCHG(IABS(I),1)/3.
497 AI=SIGN(1.,EI)
498 VI=AI-4.*EI*XW
499 NCHN=NCHN+1
500 ISIG(NCHN,1)=I
501 ISIG(NCHN,2)=-I
502 ISIG(NCHN,3)=1
503 SIGH(NCHN)=FACZG*(VI**2+AI**2)
504 280 CONTINUE
505
506 ELSEIF(ISUB.EQ.16) THEN
507C...f + fb' -> g + W+/- (q + qb' -> g + W+/- only).
508 FACWG=COMFAC*AS*AEM/XW*2./9.*(TH2+UH2+2.*SQM4*SH)/(TH*UH)
509 DO 300 I=MIN1,MAX1
510 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 300
511 IA=IABS(I)
512 DO 290 J=MIN2,MAX2
513 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 290
514 JA=IABS(J)
515 IF(I*J.GT.0.OR.MOD(IA+JA,2).EQ.0) GOTO 290
516 KCHW=(KCHG(IA,1)*ISIGN(1,I)+KCHG(JA,1)*ISIGN(1,J))/3
517 FCKM=1.
518 IF(MINT(43).EQ.4) FCKM=VCKM((IA+1)/2,(JA+1)/2)
519 NCHN=NCHN+1
520 ISIG(NCHN,1)=I
521 ISIG(NCHN,2)=J
522 ISIG(NCHN,3)=1
523 SIGH(NCHN)=FACWG*FCKM*WIDS(24,(5-KCHW)/2)
524 290 CONTINUE
525 300 CONTINUE
526
527 ELSEIF(ISUB.EQ.17) THEN
528C...f + fb -> g + H0 (q + qb -> g + H0 only).
529
530 ELSEIF(ISUB.EQ.18) THEN
531C...f + fb -> gamma + gamma.
532 FACGG=COMFAC*FACA*AEM**2*1./3.*(TH2+UH2)/(TH*UH)
533 DO 310 I=MINA,MAXA
534 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 310
535 EI=KCHG(IABS(I),1)/3.
536 NCHN=NCHN+1
537 ISIG(NCHN,1)=I
538 ISIG(NCHN,2)=-I
539 ISIG(NCHN,3)=1
540 SIGH(NCHN)=FACGG*EI**4
541 310 CONTINUE
542
543 ELSEIF(ISUB.EQ.19) THEN
544C...f + fb -> gamma + Z0.
545 FACGZ=COMFAC*FACA*AEM**2/(XW*(1.-XW))*1./24.*
546 & (TH2+UH2+2.*SQM4*SH)/(TH*UH)
547 FACGZ=FACGZ*WIDS(23,2)
548 DO 320 I=MINA,MAXA
549 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 320
550 EI=KCHG(IABS(I),1)/3.
551 AI=SIGN(1.,EI)
552 VI=AI-4.*EI*XW
553 NCHN=NCHN+1
554 ISIG(NCHN,1)=I
555 ISIG(NCHN,2)=-I
556 ISIG(NCHN,3)=1
557 SIGH(NCHN)=FACGZ*EI**2*(VI**2+AI**2)
558 320 CONTINUE
559
560 ELSEIF(ISUB.EQ.20) THEN
561C...f + fb' -> gamma + W+/-.
562 FACGW=COMFAC*FACA*AEM**2/XW*1./6.*
563 & ((2.*UH-TH)/(3.*(SH-SQM4)))**2*(TH2+UH2+2.*SQM4*SH)/(TH*UH)
564 DO 340 I=MIN1,MAX1
565 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 340
566 IA=IABS(I)
567 DO 330 J=MIN2,MAX2
568 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 330
569 JA=IABS(J)
570 IF(I*J.GT.0.OR.MOD(IA+JA,2).EQ.0) GOTO 330
571 KCHW=(KCHG(IA,1)*ISIGN(1,I)+KCHG(JA,1)*ISIGN(1,J))/3
572 FCKM=1.
573 IF(MINT(43).EQ.4) FCKM=VCKM((IA+1)/2,(JA+1)/2)
574 NCHN=NCHN+1
575 ISIG(NCHN,1)=I
576 ISIG(NCHN,2)=J
577 ISIG(NCHN,3)=1
578 SIGH(NCHN)=FACGW*FCKM*WIDS(24,(5-KCHW)/2)
579 330 CONTINUE
580 340 CONTINUE
581 ENDIF
582
583 ELSEIF(ISUB.LE.30) THEN
584 IF(ISUB.EQ.21) THEN
585C...f + fb -> gamma + H0.
586
587 ELSEIF(ISUB.EQ.22) THEN
588C...f + fb -> Z0 + Z0.
589 FACZZ=COMFAC*FACA*(AEM/(XW*(1.-XW)))**2*1./768.*
590 & (UH/TH+TH/UH+2.*(SQM3+SQM4)*SH/(TH*UH)-
591 & SQM3*SQM4*(1./TH2+1./UH2))
592 FACZZ=FACZZ*WIDS(23,1)
593 DO 350 I=MINA,MAXA
594 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 350
595 EI=KCHG(IABS(I),1)/3.
596 AI=SIGN(1.,EI)
597 VI=AI-4.*EI*XW
598 NCHN=NCHN+1
599 ISIG(NCHN,1)=I
600 ISIG(NCHN,2)=-I
601 ISIG(NCHN,3)=1
602 SIGH(NCHN)=FACZZ*(VI**4+6.*VI**2*AI**2+AI**4)
603 350 CONTINUE
604
605 ELSEIF(ISUB.EQ.23) THEN
606C...f + fb' -> Z0 + W+/-.
607 FACZW=COMFAC*FACA*(AEM/XW)**2*1./6.
608 FACZW=FACZW*WIDS(23,2)
609 THUH=MAX(TH*UH-SQM3*SQM4,SH*CKIN(3)**2)
610 DO 370 I=MIN1,MAX1
611 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 370
612 IA=IABS(I)
613 DO 360 J=MIN2,MAX2
614 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 360
615 JA=IABS(J)
616 IF(I*J.GT.0.OR.MOD(IA+JA,2).EQ.0) GOTO 360
617 KCHW=(KCHG(IA,1)*ISIGN(1,I)+KCHG(JA,1)*ISIGN(1,J))/3
618 EI=KCHG(IA,1)/3.
619 AI=SIGN(1.,EI)
620 VI=AI-4.*EI*XW
621 EJ=KCHG(JA,1)/3.
622 AJ=SIGN(1.,EJ)
623 VJ=AJ-4.*EJ*XW
624 IF(VI+AI.GT.0) THEN
625 VISAV=VI
626 AISAV=AI
627 VI=VJ
628 AI=AJ
629 VJ=VISAV
630 AJ=AISAV
631 ENDIF
632 FCKM=1.
633 IF(MINT(43).EQ.4) FCKM=VCKM((IA+1)/2,(JA+1)/2)
634 NCHN=NCHN+1
635 ISIG(NCHN,1)=I
636 ISIG(NCHN,2)=J
637 ISIG(NCHN,3)=1
638 SIGH(NCHN)=FACZW*FCKM*(1./(SH-SQMW)**2*
639 & ((9.-8.*XW)/4.*THUH+(8.*XW-6.)/4.*SH*(SQM3+SQM4))+
640 & (THUH-SH*(SQM3+SQM4))/(2.*(SH-SQMW))*((VJ+AJ)/TH-(VI+AI)/UH)+
641 & THUH/(16.*(1.-XW))*((VJ+AJ)**2/TH2+(VI+AI)**2/UH2)+
642 & SH*(SQM3+SQM4)/(8.*(1.-XW))*(VI+AI)*(VJ+AJ)/(TH*UH))*
643 & WIDS(24,(5-KCHW)/2)
644 360 CONTINUE
645 370 CONTINUE
646
647 ELSEIF(ISUB.EQ.24) THEN
648C...f + fb -> Z0 + H0.
649 THUH=MAX(TH*UH-SQM3*SQM4,SH*CKIN(3)**2)
650 FACHZ=COMFAC*FACA*(AEM/(XW*(1.-XW)))**2*1./96.*
651 & (THUH+2.*SH*SQMZ)/(SH-SQMZ)**2
652 FACHZ=FACHZ*WIDS(23,2)*WIDS(25,2)
653 DO 380 I=MINA,MAXA
654 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 380
655 EI=KCHG(IABS(I),1)/3.
656 AI=SIGN(1.,EI)
657 VI=AI-4.*EI*XW
658 NCHN=NCHN+1
659 ISIG(NCHN,1)=I
660 ISIG(NCHN,2)=-I
661 ISIG(NCHN,3)=1
662 SIGH(NCHN)=FACHZ*(VI**2+AI**2)
663 380 CONTINUE
664
665 ELSEIF(ISUB.EQ.25) THEN
666C...f + fb -> W+ + W-.
667 FACWW=COMFAC*FACA*(AEM/XW)**2*1./12.
668 FACWW=FACWW*WIDS(24,1)
669 THUH=MAX(TH*UH-SQM3*SQM4,SH*CKIN(3)**2)
670 DO 390 I=MINA,MAXA
671 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 390
672 EI=KCHG(IABS(I),1)/3.
673 AI=SIGN(1.,EI)
674 VI=AI-4.*EI*XW
675 DSIGWW=THUH/SH2*(3.-(SH-3.*(SQM3+SQM4))/(SH-SQMZ)*
676 & (VI+AI)/(2.*AI*(1.-XW))+(SH/(SH-SQMZ))**2*
677 & (1.-2.*(SQM3+SQM4)/SH+12.*SQM3*SQM4/SH2)*(VI**2+AI**2)/
678 & (8.*(1.-XW)**2))-2.*SQMZ/(SH-SQMZ)*(VI+AI)/AI+
679 & SQMZ*SH/(SH-SQMZ)**2*(1.-2.*(SQM3+SQM4)/SH)*(VI**2+AI**2)/
680 & (2.*(1.-XW))
681 IF(KCHG(IABS(I),1).LT.0) THEN
682 DSIGWW=DSIGWW+2.*(1.+SQMZ/(SH-SQMZ)*(VI+AI)/(2.*AI))*
683 & (THUH/(SH*TH)-(SQM3+SQM4)/TH)+THUH/TH2
684 ELSE
685 DSIGWW=DSIGWW+2.*(1.+SQMZ/(SH-SQMZ)*(VI+AI)/(2.*AI))*
686 & (THUH/(SH*UH)-(SQM3+SQM4)/UH)+THUH/UH2
687 ENDIF
688 NCHN=NCHN+1
689 ISIG(NCHN,1)=I
690 ISIG(NCHN,2)=-I
691 ISIG(NCHN,3)=1
692 SIGH(NCHN)=FACWW*DSIGWW
693 390 CONTINUE
694
695 ELSEIF(ISUB.EQ.26) THEN
696C...f + fb' -> W+/- + H0.
697 THUH=MAX(TH*UH-SQM3*SQM4,SH*CKIN(3)**2)
698 FACHW=COMFAC*FACA*(AEM/XW)**2*1./24.*(THUH+2.*SH*SQMW)/
699 & (SH-SQMW)**2
700 FACHW=FACHW*WIDS(25,2)
701 DO 410 I=MIN1,MAX1
702 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 410
703 IA=IABS(I)
704 DO 400 J=MIN2,MAX2
705 IF(J.EQ.0.OR.KFAC(1,J).EQ.0) GOTO 400
706 JA=IABS(J)
707 IF(I*J.GT.0.OR.MOD(IA+JA,2).EQ.0) GOTO 400
708 KCHW=(KCHG(IA,1)*ISIGN(1,I)+KCHG(JA,1)*ISIGN(1,J))/3
709 FCKM=1.
710 IF(MINT(43).EQ.4) FCKM=VCKM((IA+1)/2,(JA+1)/2)
711 NCHN=NCHN+1
712 ISIG(NCHN,1)=I
713 ISIG(NCHN,2)=J
714 ISIG(NCHN,3)=1
715 SIGH(NCHN)=FACHW*FCKM*WIDS(24,(5-KCHW)/2)
716 400 CONTINUE
717 410 CONTINUE
718
719 ELSEIF(ISUB.EQ.27) THEN
720C...f + fb -> H0 + H0.
721
722 ELSEIF(ISUB.EQ.28) THEN
723C...f + g -> f + g (q + g -> q + g only).
724 FACQG1=COMFAC*AS**2*4./9.*((2.+MSTP(34)*1./4.)*UH2/TH2-UH/SH)*
725 & FACA
726 FACQG2=COMFAC*AS**2*4./9.*((2.+MSTP(34)*1./4.)*SH2/TH2-SH/UH)
727 DO 430 I=MINA,MAXA
728 IF(I.EQ.0) GOTO 430
729 DO 420 ISDE=1,2
730 IF(ISDE.EQ.1.AND.KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 420
731 IF(ISDE.EQ.2.AND.KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 420
732 NCHN=NCHN+1
733 ISIG(NCHN,ISDE)=I
734 ISIG(NCHN,3-ISDE)=21
735 ISIG(NCHN,3)=1
736 SIGH(NCHN)=FACQG1
737 NCHN=NCHN+1
738 ISIG(NCHN,ISDE)=I
739 ISIG(NCHN,3-ISDE)=21
740 ISIG(NCHN,3)=2
741 SIGH(NCHN)=FACQG2
742 420 CONTINUE
743 430 CONTINUE
744
745 ELSEIF(ISUB.EQ.29) THEN
746C...f + g -> f + gamma (q + g -> q + gamma only).
747 FGQ=COMFAC*FACA*AS*AEM*1./3.*(SH2+UH2)/(-SH*UH)
748 DO 450 I=MINA,MAXA
749 IF(I.EQ.0) GOTO 450
750 EI=KCHG(IABS(I),1)/3.
751 FACGQ=FGQ*EI**2
752 DO 440 ISDE=1,2
753 IF(ISDE.EQ.1.AND.KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 440
754 IF(ISDE.EQ.2.AND.KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 440
755 NCHN=NCHN+1
756 ISIG(NCHN,ISDE)=I
757 ISIG(NCHN,3-ISDE)=21
758 ISIG(NCHN,3)=1
759 SIGH(NCHN)=FACGQ
760 440 CONTINUE
761 450 CONTINUE
762
763 ELSEIF(ISUB.EQ.30) THEN
764C...f + g -> f + Z0 (q + g -> q + Z0 only).
765 FZQ=COMFAC*FACA*AS*AEM/(XW*(1.-XW))*1./48.*
766 & (SH2+UH2+2.*SQM4*TH)/(-SH*UH)
767 FZQ=FZQ*WIDS(23,2)
768 DO 470 I=MINA,MAXA
769 IF(I.EQ.0) GOTO 470
770 EI=KCHG(IABS(I),1)/3.
771 AI=SIGN(1.,EI)
772 VI=AI-4.*EI*XW
773 FACZQ=FZQ*(VI**2+AI**2)
774 DO 460 ISDE=1,2
775 IF(ISDE.EQ.1.AND.KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 460
776 IF(ISDE.EQ.2.AND.KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 460
777 NCHN=NCHN+1
778 ISIG(NCHN,ISDE)=I
779 ISIG(NCHN,3-ISDE)=21
780 ISIG(NCHN,3)=1
781 SIGH(NCHN)=FACZQ
782 460 CONTINUE
783 470 CONTINUE
784 ENDIF
785
786 ELSEIF(ISUB.LE.40) THEN
787 IF(ISUB.EQ.31) THEN
788C...f + g -> f' + W+/- (q + g -> q' + W+/- only).
789 FACWQ=COMFAC*FACA*AS*AEM/XW*1./12.*
790 & (SH2+UH2+2.*SQM4*TH)/(-SH*UH)
791 DO 490 I=MINA,MAXA
792 IF(I.EQ.0) GOTO 490
793 IA=IABS(I)
794 KCHW=ISIGN(1,KCHG(IA,1)*ISIGN(1,I))
795 DO 480 ISDE=1,2
796 IF(ISDE.EQ.1.AND.KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 480
797 IF(ISDE.EQ.2.AND.KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 480
798 NCHN=NCHN+1
799 ISIG(NCHN,ISDE)=I
800 ISIG(NCHN,3-ISDE)=21
801 ISIG(NCHN,3)=1
802 SIGH(NCHN)=FACWQ*VINT(180+I)*WIDS(24,(5-KCHW)/2)
803 480 CONTINUE
804 490 CONTINUE
805
806 ELSEIF(ISUB.EQ.32) THEN
807C...f + g -> f + H0 (q + g -> q + H0 only).
808
809 ELSEIF(ISUB.EQ.33) THEN
810C...f + gamma -> f + g (q + gamma -> q + g only).
811
812 ELSEIF(ISUB.EQ.34) THEN
813C...f + gamma -> f + gamma.
814
815 ELSEIF(ISUB.EQ.35) THEN
816C...f + gamma -> f + Z0.
817
818 ELSEIF(ISUB.EQ.36) THEN
819C...f + gamma -> f' + W+/-.
820
821 ELSEIF(ISUB.EQ.37) THEN
822C...f + gamma -> f + H0.
823
824 ELSEIF(ISUB.EQ.38) THEN
825C...f + Z0 -> f + g (q + Z0 -> q + g only).
826
827 ELSEIF(ISUB.EQ.39) THEN
828C...f + Z0 -> f + gamma.
829
830 ELSEIF(ISUB.EQ.40) THEN
831C...f + Z0 -> f + Z0.
832 ENDIF
833
834 ELSEIF(ISUB.LE.50) THEN
835 IF(ISUB.EQ.41) THEN
836C...f + Z0 -> f' + W+/-.
837
838 ELSEIF(ISUB.EQ.42) THEN
839C...f + Z0 -> f + H0.
840
841 ELSEIF(ISUB.EQ.43) THEN
842C...f + W+/- -> f' + g (q + W+/- -> q' + g only).
843
844 ELSEIF(ISUB.EQ.44) THEN
845C...f + W+/- -> f' + gamma.
846
847 ELSEIF(ISUB.EQ.45) THEN
848C...f + W+/- -> f' + Z0.
849
850 ELSEIF(ISUB.EQ.46) THEN
851C...f + W+/- -> f' + W+/-.
852
853 ELSEIF(ISUB.EQ.47) THEN
854C...f + W+/- -> f' + H0.
855
856 ELSEIF(ISUB.EQ.48) THEN
857C...f + H0 -> f + g (q + H0 -> q + g only).
858
859 ELSEIF(ISUB.EQ.49) THEN
860C...f + H0 -> f + gamma.
861
862 ELSEIF(ISUB.EQ.50) THEN
863C...f + H0 -> f + Z0.
864 ENDIF
865
866 ELSEIF(ISUB.LE.60) THEN
867 IF(ISUB.EQ.51) THEN
868C...f + H0 -> f' + W+/-.
869
870 ELSEIF(ISUB.EQ.52) THEN
871C...f + H0 -> f + H0.
872
873 ELSEIF(ISUB.EQ.53) THEN
874C...g + g -> f + fb (g + g -> q + qb only).
875 CALL PYWIDT_HIJING(21,SQRT(SH),WDTP,WDTE)
876 FACQQ1=COMFAC*AS**2*1./6.*(UH/TH-(2.+MSTP(34)*1./4.)*UH2/SH2)*
877 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,3)+WDTE(0,4))*FACA
878 FACQQ2=COMFAC*AS**2*1./6.*(TH/UH-(2.+MSTP(34)*1./4.)*TH2/SH2)*
879 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,3)+WDTE(0,4))*FACA
880 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 500
881 NCHN=NCHN+1
882 ISIG(NCHN,1)=21
883 ISIG(NCHN,2)=21
884 ISIG(NCHN,3)=1
885 SIGH(NCHN)=FACQQ1
886 NCHN=NCHN+1
887 ISIG(NCHN,1)=21
888 ISIG(NCHN,2)=21
889 ISIG(NCHN,3)=2
890 SIGH(NCHN)=FACQQ2
891 500 CONTINUE
892
893 ELSEIF(ISUB.EQ.54) THEN
894C...g + gamma -> f + fb (g + gamma -> q + qb only).
895
896 ELSEIF(ISUB.EQ.55) THEN
897C...g + gamma -> f + fb (g + gamma -> q + qb only).
898
899 ELSEIF(ISUB.EQ.56) THEN
900C...g + gamma -> f + fb (g + gamma -> q + qb only).
901
902 ELSEIF(ISUB.EQ.57) THEN
903C...g + gamma -> f + fb (g + gamma -> q + qb only).
904
905 ELSEIF(ISUB.EQ.58) THEN
906C...gamma + gamma -> f + fb.
907
908 ELSEIF(ISUB.EQ.59) THEN
909C...gamma + Z0 -> f + fb.
910
911 ELSEIF(ISUB.EQ.60) THEN
912C...gamma + W+/- -> f + fb'.
913 ENDIF
914
915 ELSEIF(ISUB.LE.70) THEN
916 IF(ISUB.EQ.61) THEN
917C...gamma + H0 -> f + fb.
918
919 ELSEIF(ISUB.EQ.62) THEN
920C...Z0 + Z0 -> f + fb.
921
922 ELSEIF(ISUB.EQ.63) THEN
923C...Z0 + W+/- -> f + fb'.
924
925 ELSEIF(ISUB.EQ.64) THEN
926C...Z0 + H0 -> f + fb.
927
928 ELSEIF(ISUB.EQ.65) THEN
929C...W+ + W- -> f + fb.
930
931 ELSEIF(ISUB.EQ.66) THEN
932C...W+/- + H0 -> f + fb'.
933
934 ELSEIF(ISUB.EQ.67) THEN
935C...H0 + H0 -> f + fb.
936
937 ELSEIF(ISUB.EQ.68) THEN
938C...g + g -> g + g.
939 FACGG1=COMFAC*AS**2*9./4.*(SH2/TH2+2.*SH/TH+3.+2.*TH/SH+
940 & TH2/SH2)*FACA
941 FACGG2=COMFAC*AS**2*9./4.*(UH2/SH2+2.*UH/SH+3.+2.*SH/UH+
942 & SH2/UH2)*FACA
943 FACGG3=COMFAC*AS**2*9./4.*(TH2/UH2+2.*TH/UH+3+2.*UH/TH+UH2/TH2)
944 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 510
945 NCHN=NCHN+1
946 ISIG(NCHN,1)=21
947 ISIG(NCHN,2)=21
948 ISIG(NCHN,3)=1
949 SIGH(NCHN)=0.5*FACGG1
950 NCHN=NCHN+1
951 ISIG(NCHN,1)=21
952 ISIG(NCHN,2)=21
953 ISIG(NCHN,3)=2
954 SIGH(NCHN)=0.5*FACGG2
955 NCHN=NCHN+1
956 ISIG(NCHN,1)=21
957 ISIG(NCHN,2)=21
958 ISIG(NCHN,3)=3
959 SIGH(NCHN)=0.5*FACGG3
960 510 CONTINUE
961
962 ELSEIF(ISUB.EQ.69) THEN
963C...gamma + gamma -> W+ + W-.
964
965 ELSEIF(ISUB.EQ.70) THEN
966C...gamma + W+/- -> gamma + W+/-.
967 ENDIF
968
969 ELSEIF(ISUB.LE.80) THEN
970 IF(ISUB.EQ.71) THEN
971C...Z0 + Z0 -> Z0 + Z0.
972 BE2=1.-4.*SQMZ/SH
973 TH=-0.5*SH*BE2*(1.-CTH)
974 UH=-0.5*SH*BE2*(1.+CTH)
975 SHANG=1./(1.-XW)*SQMW/SQMZ*(1.+BE2)**2
976 ASHRE=(SH-SQMH)/((SH-SQMH)**2+GMMH**2)*SHANG
977 ASHIM=-GMMH/((SH-SQMH)**2+GMMH**2)*SHANG
978 THANG=1./(1.-XW)*SQMW/SQMZ*(BE2-CTH)**2
979 ATHRE=(TH-SQMH)/((TH-SQMH)**2+GMMH**2)*THANG
980 ATHIM=-GMMH/((TH-SQMH)**2+GMMH**2)*THANG
981 UHANG=1./(1.-XW)*SQMW/SQMZ*(BE2+CTH)**2
982 AUHRE=(UH-SQMH)/((UH-SQMH)**2+GMMH**2)*UHANG
983 AUHIM=-GMMH/((UH-SQMH)**2+GMMH**2)*UHANG
984 FACH=0.5*COMFAC*1./(4096.*PARU(1)**2*16.*(1.-XW)**2)*
985 & (AEM/XW)**4*(SH/SQMW)**2*((ASHRE+ATHRE+AUHRE)**2+
986 & (ASHIM+ATHIM+AUHIM)**2)*SQMZ/SQMW
987 DO 530 I=MIN1,MAX1
988 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 530
989 EI=KCHG(IABS(I),1)/3.
990 AI=SIGN(1.,EI)
991 VI=AI-4.*EI*XW
992 AVI=AI**2+VI**2
993 DO 520 J=MIN2,MAX2
994 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 520
995 EJ=KCHG(IABS(J),1)/3.
996 AJ=SIGN(1.,EJ)
997 VJ=AJ-4.*EJ*XW
998 AVJ=AJ**2+VJ**2
999 NCHN=NCHN+1
1000 ISIG(NCHN,1)=I
1001 ISIG(NCHN,2)=J
1002 ISIG(NCHN,3)=1
1003 SIGH(NCHN)=FACH*AVI*AVJ
1004 520 CONTINUE
1005 530 CONTINUE
1006
1007 ELSEIF(ISUB.EQ.72) THEN
1008C...Z0 + Z0 -> W+ + W-.
1009 BE2=SQRT((1.-4.*SQMW/SH)*(1.-4.*SQMZ/SH))
1010 CTH2=CTH**2
1011 TH=-0.5*SH*(1.-2.*(SQMW+SQMZ)/SH-BE2*CTH)
1012 UH=-0.5*SH*(1.-2.*(SQMW+SQMZ)/SH+BE2*CTH)
1013 SHANG=4.*SQRT(SQMW/(SQMZ*(1.-XW)))*(1.-2.*SQMW/SH)*
1014 & (1.-2.*SQMZ/SH)
1015 ASHRE=(SH-SQMH)/((SH-SQMH)**2+GMMH**2)*SHANG
1016 ASHIM=-GMMH/((SH-SQMH)**2+GMMH**2)*SHANG
1017 ATWRE=(1.-XW)/SQMZ*SH/(TH-SQMW)*((CTH-BE2)**2*(3./2.+BE2/2.*CTH-
1018 & (SQMW+SQMZ)/SH+(SQMW-SQMZ)**2/(SH*SQMW))+4.*((SQMW+SQMZ)/SH*
1019 & (1.-3.*CTH2)+8.*SQMW*SQMZ/SH2*(2.*CTH2-1.)+
1020 & 4.*(SQMW**2+SQMZ**2)/SH2*CTH2+2.*(SQMW+SQMZ)/SH*BE2*CTH))
1021 ATWIM=0.
1022 AUWRE=(1.-XW)/SQMZ*SH/(UH-SQMW)*((CTH+BE2)**2*(3./2.-BE2/2.*CTH-
1023 & (SQMW+SQMZ)/SH+(SQMW-SQMZ)**2/(SH*SQMW))+4.*((SQMW+SQMZ)/SH*
1024 & (1.-3.*CTH2)+8.*SQMW*SQMZ/SH2*(2.*CTH2-1.)+
1025 & 4.*(SQMW**2+SQMZ**2)/SH2*CTH2-2.*(SQMW+SQMZ)/SH*BE2*CTH))
1026 AUWIM=0.
1027 A4RE=2.*(1.-XW)/SQMZ*(3.-CTH2-4.*(SQMW+SQMZ)/SH)
1028 A4IM=0.
1029 FACH=COMFAC*1./(4096.*PARU(1)**2*16.*(1.-XW)**2)*(AEM/XW)**4*
1030 & (SH/SQMW)**2*((ASHRE+ATWRE+AUWRE+A4RE)**2+
1031 & (ASHIM+ATWIM+AUWIM+A4IM)**2)*SQMZ/SQMW
1032 DO 550 I=MIN1,MAX1
1033 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 550
1034 EI=KCHG(IABS(I),1)/3.
1035 AI=SIGN(1.,EI)
1036 VI=AI-4.*EI*XW
1037 AVI=AI**2+VI**2
1038 DO 540 J=MIN2,MAX2
1039 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 540
1040 EJ=KCHG(IABS(J),1)/3.
1041 AJ=SIGN(1.,EJ)
1042 VJ=AJ-4.*EJ*XW
1043 AVJ=AJ**2+VJ**2
1044 NCHN=NCHN+1
1045 ISIG(NCHN,1)=I
1046 ISIG(NCHN,2)=J
1047 ISIG(NCHN,3)=1
1048 SIGH(NCHN)=FACH*AVI*AVJ
1049 540 CONTINUE
1050 550 CONTINUE
1051
1052 ELSEIF(ISUB.EQ.73) THEN
1053C...Z0 + W+/- -> Z0 + W+/-.
1054 BE2=1.-2.*(SQMZ+SQMW)/SH+((SQMZ-SQMW)/SH)**2
1055 EP1=1.+(SQMZ-SQMW)/SH
1056 EP2=1.-(SQMZ-SQMW)/SH
1057 TH=-0.5*SH*BE2*(1.-CTH)
1058 UH=(SQMZ-SQMW)**2/SH-0.5*SH*BE2*(1.+CTH)
1059 THANG=SQRT(SQMW/(SQMZ*(1.-XW)))*(BE2-EP1*CTH)*(BE2-EP2*CTH)
1060 ATHRE=(TH-SQMH)/((TH-SQMH)**2+GMMH**2)*THANG
1061 ATHIM=-GMMH/((TH-SQMH)**2+GMMH**2)*THANG
1062 ASWRE=(1.-XW)/SQMZ*SH/(SH-SQMW)*(-BE2*(EP1+EP2)**4*CTH+
1063 & 1./4.*(BE2+EP1*EP2)**2*((EP1-EP2)**2-4.*BE2*CTH)+
1064 & 2.*BE2*(BE2+EP1*EP2)*(EP1+EP2)**2*CTH-
1065 & 1./16.*SH/SQMW*(EP1**2-EP2**2)**2*(BE2+EP1*EP2)**2)
1066 ASWIM=0.
1067 AUWRE=(1.-XW)/SQMZ*SH/(UH-SQMW)*(-BE2*(EP2+EP1*CTH)*
1068 & (EP1+EP2*CTH)*(BE2+EP1*EP2)+BE2*(EP2+EP1*CTH)*
1069 & (BE2+EP1*EP2*CTH)*(2.*EP2-EP2*CTH+EP1)-BE2*(EP2+EP1*CTH)**2*
1070 & (BE2-EP2**2*CTH)-1./8.*(BE2+EP1*EP2*CTH)**2*((EP1+EP2)**2+
1071 & 2.*BE2*(1.-CTH))+1./32.*SH/SQMW*(BE2+EP1*EP2*CTH)**2*
1072 & (EP1**2-EP2**2)**2-BE2*(EP1+EP2*CTH)*(EP2+EP1*CTH)*
1073 & (BE2+EP1*EP2)+BE2*(EP1+EP2*CTH)*(BE2+EP1*EP2*CTH)*
1074 & (2.*EP1-EP1*CTH+EP2)-BE2*(EP1+EP2*CTH)**2*(BE2-EP1**2*CTH)-
1075 & 1./8.*(BE2+EP1*EP2*CTH)**2*((EP1+EP2)**2+2.*BE2*(1.-CTH))+
1076 & 1./32.*SH/SQMW*(BE2+EP1*EP2*CTH)**2*(EP1**2-EP2**2)**2)
1077 AUWIM=0.
1078 A4RE=(1.-XW)/SQMZ*(EP1**2*EP2**2*(CTH**2-1.)-
1079 & 2.*BE2*(EP1**2+EP2**2+EP1*EP2)*CTH-2.*BE2*EP1*EP2)
1080 A4IM=0.
1081 FACH=COMFAC*1./(4096.*PARU(1)**2*4.*(1.-XW))*(AEM/XW)**4*
1082 & (SH/SQMW)**2*((ATHRE+ASWRE+AUWRE+A4RE)**2+
1083 & (ATHIM+ASWIM+AUWIM+A4IM)**2)*SQRT(SQMZ/SQMW)
1084 DO 570 I=MIN1,MAX1
1085 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 570
1086 EI=KCHG(IABS(I),1)/3.
1087 AI=SIGN(1.,EI)
1088 VI=AI-4.*EI*XW
1089 AVI=AI**2+VI**2
1090 DO 560 J=MIN2,MAX2
1091 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 560
1092 EJ=KCHG(IABS(J),1)/3.
1093 AJ=SIGN(1.,EJ)
1094 VJ=AI-4.*EJ*XW
1095 AVJ=AJ**2+VJ**2
1096 NCHN=NCHN+1
1097 ISIG(NCHN,1)=I
1098 ISIG(NCHN,2)=J
1099 ISIG(NCHN,3)=1
1100 SIGH(NCHN)=FACH*(AVI*VINT(180+J)+VINT(180+I)*AVJ)
1101 560 CONTINUE
1102 570 CONTINUE
1103
1104 ELSEIF(ISUB.EQ.75) THEN
1105C...W+ + W- -> gamma + gamma.
1106
1107 ELSEIF(ISUB.EQ.76) THEN
1108C...W+ + W- -> Z0 + Z0.
1109 BE2=SQRT((1.-4.*SQMW/SH)*(1.-4.*SQMZ/SH))
1110 CTH2=CTH**2
1111 TH=-0.5*SH*(1.-2.*(SQMW+SQMZ)/SH-BE2*CTH)
1112 UH=-0.5*SH*(1.-2.*(SQMW+SQMZ)/SH+BE2*CTH)
1113 SHANG=4.*SQRT(SQMW/(SQMZ*(1.-XW)))*(1.-2.*SQMW/SH)*
1114 & (1.-2.*SQMZ/SH)
1115 ASHRE=(SH-SQMH)/((SH-SQMH)**2+GMMH**2)*SHANG
1116 ASHIM=-GMMH/((SH-SQMH)**2+GMMH**2)*SHANG
1117 ATWRE=(1.-XW)/SQMZ*SH/(TH-SQMW)*((CTH-BE2)**2*(3./2.+BE2/2.*CTH-
1118 & (SQMW+SQMZ)/SH+(SQMW-SQMZ)**2/(SH*SQMW))+4.*((SQMW+SQMZ)/SH*
1119 & (1.-3.*CTH2)+8.*SQMW*SQMZ/SH2*(2.*CTH2-1.)+
1120 & 4.*(SQMW**2+SQMZ**2)/SH2*CTH2+2.*(SQMW+SQMZ)/SH*BE2*CTH))
1121 ATWIM=0.
1122 AUWRE=(1.-XW)/SQMZ*SH/(UH-SQMW)*((CTH+BE2)**2*(3./2.-BE2/2.*CTH-
1123 & (SQMW+SQMZ)/SH+(SQMW-SQMZ)**2/(SH*SQMW))+4.*((SQMW+SQMZ)/SH*
1124 & (1.-3.*CTH2)+8.*SQMW*SQMZ/SH2*(2.*CTH2-1.)+
1125 & 4.*(SQMW**2+SQMZ**2)/SH2*CTH2-2.*(SQMW+SQMZ)/SH*BE2*CTH))
1126 AUWIM=0.
1127 A4RE=2.*(1.-XW)/SQMZ*(3.-CTH2-4.*(SQMW+SQMZ)/SH)
1128 A4IM=0.
1129 FACH=0.5*COMFAC*1./(4096.*PARU(1)**2)*(AEM/XW)**4*(SH/SQMW)**2*
1130 & ((ASHRE+ATWRE+AUWRE+A4RE)**2+(ASHIM+ATWIM+AUWIM+A4IM)**2)
1131 DO 590 I=MIN1,MAX1
1132 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 590
1133 EI=SIGN(1.,FLOAT(I))*KCHG(IABS(I),1)
1134 DO 580 J=MIN2,MAX2
1135 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 580
1136 EJ=SIGN(1.,FLOAT(J))*KCHG(IABS(J),1)
1137 IF(EI*EJ.GT.0.) GOTO 580
1138 NCHN=NCHN+1
1139 ISIG(NCHN,1)=I
1140 ISIG(NCHN,2)=J
1141 ISIG(NCHN,3)=1
1142 SIGH(NCHN)=FACH*VINT(180+I)*VINT(180+J)
1143 580 CONTINUE
1144 590 CONTINUE
1145
1146 ELSEIF(ISUB.EQ.77) THEN
1147C...W+/- + W+/- -> W+/- + W+/-.
1148 BE2=1.-4.*SQMW/SH
1149 BE4=BE2**2
1150 CTH2=CTH**2
1151 CTH3=CTH**3
1152 TH=-0.5*SH*BE2*(1.-CTH)
1153 UH=-0.5*SH*BE2*(1.+CTH)
1154 SHANG=(1.+BE2)**2
1155 ASHRE=(SH-SQMH)/((SH-SQMH)**2+GMMH**2)*SHANG
1156 ASHIM=-GMMH/((SH-SQMH)**2+GMMH**2)*SHANG
1157 THANG=(BE2-CTH)**2
1158 ATHRE=(TH-SQMH)/((TH-SQMH)**2+GMMH**2)*THANG
1159 ATHIM=-GMMH/((TH-SQMH)**2+GMMH**2)*THANG
1160 SGZANG=1./SQMW*BE2*(3.-BE2)**2*CTH
1161 ASGRE=XW*SGZANG
1162 ASGIM=0.
1163 ASZRE=(1.-XW)*SH/(SH-SQMZ)*SGZANG
1164 ASZIM=0.
1165 TGZANG=1./SQMW*(BE2*(4.-2.*BE2+BE4)+BE2*(4.-10.*BE2+BE4)*CTH+
1166 & (2.-11.*BE2+10.*BE4)*CTH2+BE2*CTH3)
1167 ATGRE=0.5*XW*SH/TH*TGZANG
1168 ATGIM=0.
1169 ATZRE=0.5*(1.-XW)*SH/(TH-SQMZ)*TGZANG
1170 ATZIM=0.
1171 A4RE=1./SQMW*(1.+2.*BE2-6.*BE2*CTH-CTH2)
1172 A4IM=0.
1173 FACH=COMFAC*1./(4096.*PARU(1)**2)*(AEM/XW)**4*(SH/SQMW)**2*
1174 & ((ASHRE+ATHRE+ASGRE+ASZRE+ATGRE+ATZRE+A4RE)**2+
1175 & (ASHIM+ATHIM+ASGIM+ASZIM+ATGIM+ATZIM+A4IM)**2)
1176 DO 610 I=MIN1,MAX1
1177 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 610
1178 EI=SIGN(1.,FLOAT(I))*KCHG(IABS(I),1)
1179 DO 600 J=MIN2,MAX2
1180 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 600
1181 EJ=SIGN(1.,FLOAT(J))*KCHG(IABS(J),1)
1182 IF(EI*EJ.GT.0.) GOTO 600
1183 NCHN=NCHN+1
1184 ISIG(NCHN,1)=I
1185 ISIG(NCHN,2)=J
1186 ISIG(NCHN,3)=1
1187 SIGH(NCHN)=FACH*VINT(180+I)*VINT(180+J)
1188 600 CONTINUE
1189 610 CONTINUE
1190
1191 ELSEIF(ISUB.EQ.78) THEN
1192C...W+/- + H0 -> W+/- + H0.
1193
1194 ELSEIF(ISUB.EQ.79) THEN
1195C...H0 + H0 -> H0 + H0.
1196
1197 ENDIF
1198
1199C...C: 2 -> 2, tree diagrams with masses.
1200
1201 ELSEIF(ISUB.LE.90) THEN
1202 IF(ISUB.EQ.81) THEN
1203C...q + qb -> Q + QB.
1204 FACQQB=COMFAC*AS**2*4./9.*(((TH-SQM3)**2+
1205 & (UH-SQM3)**2)/SH2+2.*SQM3/SH)
1206 IF(MSTP(35).GE.1) THEN
1207 IF(MSTP(35).EQ.1) THEN
1208 ALSSG=PARP(35)
1209 ELSE
1210 MST115=MSTU(115)
1211 MSTU(115)=MSTP(36)
1212 Q2BN=SQRT(SQM3*((SQRT(SH)-2.*SQRT(SQM3))**2+PARP(36)**2))
1213 ALSSG=ULALPS_HIJING(Q2BN)
1214 MSTU(115)=MST115
1215 ENDIF
1216 XREPU=PARU(1)*ALSSG/(6.*SQRT(MAX(1E-20,1.-4.*SQM3/SH)))
1217 FREPU=XREPU/(EXP(MIN(100.,XREPU))-1.)
1218 PARI(81)=FREPU
1219 FACQQB=FACQQB*FREPU
1220 ENDIF
1221 DO 620 I=MINA,MAXA
1222 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 620
1223 NCHN=NCHN+1
1224 ISIG(NCHN,1)=I
1225 ISIG(NCHN,2)=-I
1226 ISIG(NCHN,3)=1
1227 SIGH(NCHN)=FACQQB
1228 620 CONTINUE
1229
1230 ELSEIF(ISUB.EQ.82) THEN
1231C...g + g -> Q + QB.
1232 FACQQ1=COMFAC*FACA*AS**2*1./6.*((UH-SQM3)/(TH-SQM3)-
1233 & 2.*(UH-SQM3)**2/SH2+4.*SQM3/SH*(TH*UH-SQM3**2)/(TH-SQM3)**2)
1234 FACQQ2=COMFAC*FACA*AS**2*1./6.*((TH-SQM3)/(UH-SQM3)-
1235 & 2.*(TH-SQM3)**2/SH2+4.*SQM3/SH*(TH*UH-SQM3**2)/(UH-SQM3)**2)
1236 IF(MSTP(35).GE.1) THEN
1237 IF(MSTP(35).EQ.1) THEN
1238 ALSSG=PARP(35)
1239 ELSE
1240 MST115=MSTU(115)
1241 MSTU(115)=MSTP(36)
1242 Q2BN=SQRT(SQM3*((SQRT(SH)-2.*SQRT(SQM3))**2+PARP(36)**2))
1243 ALSSG=ULALPS_HIJING(Q2BN)
1244 MSTU(115)=MST115
1245 ENDIF
1246 XATTR=4.*PARU(1)*ALSSG/(3.*SQRT(MAX(1E-20,1.-4.*SQM3/SH)))
1247 FATTR=XATTR/(1.-EXP(-MIN(100.,XATTR)))
1248 XREPU=PARU(1)*ALSSG/(6.*SQRT(MAX(1E-20,1.-4.*SQM3/SH)))
1249 FREPU=XREPU/(EXP(MIN(100.,XREPU))-1.)
1250 FATRE=(2.*FATTR+5.*FREPU)/7.
1251 PARI(81)=FATRE
1252 FACQQ1=FACQQ1*FATRE
1253 FACQQ2=FACQQ2*FATRE
1254 ENDIF
1255 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 630
1256 NCHN=NCHN+1
1257 ISIG(NCHN,1)=21
1258 ISIG(NCHN,2)=21
1259 ISIG(NCHN,3)=1
1260 SIGH(NCHN)=FACQQ1
1261 NCHN=NCHN+1
1262 ISIG(NCHN,1)=21
1263 ISIG(NCHN,2)=21
1264 ISIG(NCHN,3)=2
1265 SIGH(NCHN)=FACQQ2
1266 630 CONTINUE
1267
1268 ENDIF
1269
1270C...D: Mimimum bias processes.
1271
1272 ELSEIF(ISUB.LE.100) THEN
1273 IF(ISUB.EQ.91) THEN
1274C...Elastic scattering.
1275 SIGS=XSEC(ISUB,1)
1276
1277 ELSEIF(ISUB.EQ.92) THEN
1278C...Single diffractive scattering.
1279 SIGS=XSEC(ISUB,1)
1280
1281 ELSEIF(ISUB.EQ.93) THEN
1282C...Double diffractive scattering.
1283 SIGS=XSEC(ISUB,1)
1284
1285 ELSEIF(ISUB.EQ.94) THEN
1286C...Central diffractive scattering.
1287 SIGS=XSEC(ISUB,1)
1288
1289 ELSEIF(ISUB.EQ.95) THEN
1290C...Low-pT scattering.
1291 SIGS=XSEC(ISUB,1)
1292
1293 ELSEIF(ISUB.EQ.96) THEN
1294C...Multiple interactions: sum of QCD processes.
1295 CALL PYWIDT_HIJING(21,SQRT(SH),WDTP,WDTE)
1296
1297C...q + q' -> q + q'.
1298 FACQQ1=COMFAC*AS**2*4./9.*(SH2+UH2)/TH2
1299 FACQQB=COMFAC*AS**2*4./9.*((SH2+UH2)/TH2*FACA-
1300 & MSTP(34)*2./3.*UH2/(SH*TH))
1301 FACQQ2=COMFAC*AS**2*4./9.*((SH2+TH2)/UH2-
1302 & MSTP(34)*2./3.*SH2/(TH*UH))
1303 DO 650 I=-3,3
1304 IF(I.EQ.0) GOTO 650
1305 DO 640 J=-3,3
1306 IF(J.EQ.0) GOTO 640
1307 NCHN=NCHN+1
1308 ISIG(NCHN,1)=I
1309 ISIG(NCHN,2)=J
1310 ISIG(NCHN,3)=111
1311 SIGH(NCHN)=FACQQ1
1312 IF(I.EQ.-J) SIGH(NCHN)=FACQQB
1313 IF(I.EQ.J) THEN
1314 SIGH(NCHN)=0.5*SIGH(NCHN)
1315 NCHN=NCHN+1
1316 ISIG(NCHN,1)=I
1317 ISIG(NCHN,2)=J
1318 ISIG(NCHN,3)=112
1319 SIGH(NCHN)=0.5*FACQQ2
1320 ENDIF
1321 640 CONTINUE
1322 650 CONTINUE
1323
1324C...q + qb -> q' + qb' or g + g.
1325 FACQQB=COMFAC*AS**2*4./9.*(TH2+UH2)/SH2*(WDTE(0,1)+WDTE(0,2)+
1326 & WDTE(0,3)+WDTE(0,4))
1327 FACGG1=COMFAC*AS**2*32./27.*(UH/TH-(2.+MSTP(34)*1./4.)*UH2/SH2)
1328 FACGG2=COMFAC*AS**2*32./27.*(TH/UH-(2.+MSTP(34)*1./4.)*TH2/SH2)
1329 DO 660 I=-3,3
1330 IF(I.EQ.0) GOTO 660
1331 NCHN=NCHN+1
1332 ISIG(NCHN,1)=I
1333 ISIG(NCHN,2)=-I
1334 ISIG(NCHN,3)=121
1335 SIGH(NCHN)=FACQQB
1336 NCHN=NCHN+1
1337 ISIG(NCHN,1)=I
1338 ISIG(NCHN,2)=-I
1339 ISIG(NCHN,3)=131
1340 SIGH(NCHN)=0.5*FACGG1
1341 NCHN=NCHN+1
1342 ISIG(NCHN,1)=I
1343 ISIG(NCHN,2)=-I
1344 ISIG(NCHN,3)=132
1345 SIGH(NCHN)=0.5*FACGG2
1346 660 CONTINUE
1347
1348C...q + g -> q + g.
1349 FACQG1=COMFAC*AS**2*4./9.*((2.+MSTP(34)*1./4.)*UH2/TH2-UH/SH)*
1350 & FACA
1351 FACQG2=COMFAC*AS**2*4./9.*((2.+MSTP(34)*1./4.)*SH2/TH2-SH/UH)
1352 DO 680 I=-3,3
1353 IF(I.EQ.0) GOTO 680
1354 DO 670 ISDE=1,2
1355 NCHN=NCHN+1
1356 ISIG(NCHN,ISDE)=I
1357 ISIG(NCHN,3-ISDE)=21
1358 ISIG(NCHN,3)=281
1359 SIGH(NCHN)=FACQG1
1360 NCHN=NCHN+1
1361 ISIG(NCHN,ISDE)=I
1362 ISIG(NCHN,3-ISDE)=21
1363 ISIG(NCHN,3)=282
1364 SIGH(NCHN)=FACQG2
1365 670 CONTINUE
1366 680 CONTINUE
1367
1368C...g + g -> q + qb or g + g.
1369 FACQQ1=COMFAC*AS**2*1./6.*(UH/TH-(2.+MSTP(34)*1./4.)*UH2/SH2)*
1370 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,3)+WDTE(0,4))*FACA
1371 FACQQ2=COMFAC*AS**2*1./6.*(TH/UH-(2.+MSTP(34)*1./4.)*TH2/SH2)*
1372 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,3)+WDTE(0,4))*FACA
1373 FACGG1=COMFAC*AS**2*9./4.*(SH2/TH2+2.*SH/TH+3.+2.*TH/SH+
1374 & TH2/SH2)*FACA
1375 FACGG2=COMFAC*AS**2*9./4.*(UH2/SH2+2.*UH/SH+3.+2.*SH/UH+
1376 & SH2/UH2)*FACA
1377 FACGG3=COMFAC*AS**2*9./4.*(TH2/UH2+2.*TH/UH+3+2.*UH/TH+UH2/TH2)
1378 NCHN=NCHN+1
1379 ISIG(NCHN,1)=21
1380 ISIG(NCHN,2)=21
1381 ISIG(NCHN,3)=531
1382 SIGH(NCHN)=FACQQ1
1383 NCHN=NCHN+1
1384 ISIG(NCHN,1)=21
1385 ISIG(NCHN,2)=21
1386 ISIG(NCHN,3)=532
1387 SIGH(NCHN)=FACQQ2
1388 NCHN=NCHN+1
1389 ISIG(NCHN,1)=21
1390 ISIG(NCHN,2)=21
1391 ISIG(NCHN,3)=681
1392 SIGH(NCHN)=0.5*FACGG1
1393 NCHN=NCHN+1
1394 ISIG(NCHN,1)=21
1395 ISIG(NCHN,2)=21
1396 ISIG(NCHN,3)=682
1397 SIGH(NCHN)=0.5*FACGG2
1398 NCHN=NCHN+1
1399 ISIG(NCHN,1)=21
1400 ISIG(NCHN,2)=21
1401 ISIG(NCHN,3)=683
1402 SIGH(NCHN)=0.5*FACGG3
1403 ENDIF
1404
1405C...E: 2 -> 1, loop diagrams.
1406
1407 ELSEIF(ISUB.LE.110) THEN
1408 IF(ISUB.EQ.101) THEN
1409C...g + g -> gamma*/Z0.
1410
1411 ELSEIF(ISUB.EQ.102) THEN
1412C...g + g -> H0.
1413 CALL PYWIDT_HIJING(25,SQRT(SH),WDTP,WDTE)
1414 ETARE=0.
1415 ETAIM=0.
1416 DO 690 I=1,2*MSTP(1)
1417 EPS=4.*PMAS(I,1)**2/SH
1418 IF(EPS.LE.1.) THEN
1419 IF(EPS.GT.1.E-4) THEN
1420 ROOT=SQRT(1.-EPS)
1421 RLN=LOG((1.+ROOT)/(1.-ROOT))
1422 ELSE
1423 RLN=LOG(4./EPS-2.)
1424 ENDIF
1425 PHIRE=0.25*(RLN**2-PARU(1)**2)
1426 PHIIM=0.5*PARU(1)*RLN
1427 ELSE
1428 PHIRE=-(ASIN(1./SQRT(EPS)))**2
1429 PHIIM=0.
1430 ENDIF
1431 ETARE=ETARE+0.5*EPS*(1.+(EPS-1.)*PHIRE)
1432 ETAIM=ETAIM+0.5*EPS*(EPS-1.)*PHIIM
1433 690 CONTINUE
1434 ETA2=ETARE**2+ETAIM**2
1435 FACH=COMFAC*FACA*(AS/PARU(1)*AEM/XW)**2*1./512.*
1436 & (SH/SQMW)**2*ETA2*SH2/((SH-SQMH)**2+GMMH**2)*
1437 & (WDTE(0,1)+WDTE(0,2)+WDTE(0,4))
1438 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 700
1439 NCHN=NCHN+1
1440 ISIG(NCHN,1)=21
1441 ISIG(NCHN,2)=21
1442 ISIG(NCHN,3)=1
1443 SIGH(NCHN)=FACH
1444 700 CONTINUE
1445
1446 ENDIF
1447
1448C...F: 2 -> 2, box diagrams.
1449
1450 ELSEIF(ISUB.LE.120) THEN
1451 IF(ISUB.EQ.111) THEN
1452C...f + fb -> g + H0 (q + qb -> g + H0 only).
1453 A5STUR=0.
1454 A5STUI=0.
1455 DO 710 I=1,2*MSTP(1)
1456 SQMQ=PMAS(I,1)**2
1457 EPSS=4.*SQMQ/SH
1458 EPSH=4.*SQMQ/SQMH
1459 A5STUR=A5STUR+SQMQ/SQMH*(4.+4.*SH/(TH+UH)*(PYW1AU_HIJING(EPSS,1)
1460 $ -PYW1AU_HIJING(EPSH,1))+(1.-4.*SQMQ/(TH+UH))
1461 $ *(PYW2AU_HIJING(EPSS,1)-PYW2AU_HIJING(EPSH,1)))
1462 A5STUI=A5STUI+SQMQ/SQMH*(4.*SH/(TH+UH)*(PYW1AU_HIJING(EPSS,2)-
1463 & PYW1AU_HIJING(EPSH,2))+(1.-4.*SQMQ/(TH+UH))
1464 $ *(PYW2AU_HIJING(EPSS,2)-PYW2AU_HIJING(EPSH,2)))
1465 710 CONTINUE
1466 FACGH=COMFAC*FACA/(144.*PARU(1)**2)*AEM/XW*AS**3*SQMH/SQMW*
1467 & SQMH/SH*(UH**2+TH**2)/(UH+TH)**2*(A5STUR**2+A5STUI**2)
1468 FACGH=FACGH*WIDS(25,2)
1469 DO 720 I=MINA,MAXA
1470 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 720
1471 NCHN=NCHN+1
1472 ISIG(NCHN,1)=I
1473 ISIG(NCHN,2)=-I
1474 ISIG(NCHN,3)=1
1475 SIGH(NCHN)=FACGH
1476 720 CONTINUE
1477
1478 ELSEIF(ISUB.EQ.112) THEN
1479C...f + g -> f + H0 (q + g -> q + H0 only).
1480 A5TSUR=0.
1481 A5TSUI=0.
1482 DO 730 I=1,2*MSTP(1)
1483 SQMQ=PMAS(I,1)**2
1484 EPST=4.*SQMQ/TH
1485 EPSH=4.*SQMQ/SQMH
1486 A5TSUR=A5TSUR+SQMQ/SQMH*(4.+4.*TH/(SH+UH)*(PYW1AU_HIJING(EPST,1)
1487 $ -PYW1AU_HIJING(EPSH,1))+(1.-4.*SQMQ/(SH+UH))
1488 $ *(PYW2AU_HIJING(EPST,1)-PYW2AU_HIJING(EPSH,1)))
1489 A5TSUI=A5TSUI+SQMQ/SQMH*(4.*TH/(SH+UH)*(PYW1AU_HIJING(EPST,2)-
1490 & PYW1AU_HIJING(EPSH,2))+(1.-4.*SQMQ/(SH+UH))
1491 $ *(PYW2AU_HIJING(EPST,2)-PYW2AU_HIJING(EPSH,2)))
1492 730 CONTINUE
1493 FACQH=COMFAC*FACA/(384.*PARU(1)**2)*AEM/XW*AS**3*SQMH/SQMW*
1494 & SQMH/(-TH)*(UH**2+SH**2)/(UH+SH)**2*(A5TSUR**2+A5TSUI**2)
1495 FACQH=FACQH*WIDS(25,2)
1496 DO 750 I=MINA,MAXA
1497 IF(I.EQ.0) GOTO 750
1498 DO 740 ISDE=1,2
1499 IF(ISDE.EQ.1.AND.KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 740
1500 IF(ISDE.EQ.2.AND.KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 740
1501 NCHN=NCHN+1
1502 ISIG(NCHN,ISDE)=I
1503 ISIG(NCHN,3-ISDE)=21
1504 ISIG(NCHN,3)=1
1505 SIGH(NCHN)=FACQH
1506 740 CONTINUE
1507 750 CONTINUE
1508
1509 ELSEIF(ISUB.EQ.113) THEN
1510C...g + g -> g + H0.
1511 A2STUR=0.
1512 A2STUI=0.
1513 A2USTR=0.
1514 A2USTI=0.
1515 A2TUSR=0.
1516 A2TUSI=0.
1517 A4STUR=0.
1518 A4STUI=0.
1519 DO 760 I=6,2*MSTP(1)
1520C'''Only t-quarks yet included
1521 SQMQ=PMAS(I,1)**2
1522 EPSS=4.*SQMQ/SH
1523 EPST=4.*SQMQ/TH
1524 EPSU=4.*SQMQ/UH
1525 EPSH=4.*SQMQ/SQMH
1526 IF(EPSH.LT.1.E-6) GOTO 760
1527 BESTU=0.5*(1.+SQRT(1.+EPSS*TH/UH))
1528 BEUST=0.5*(1.+SQRT(1.+EPSU*SH/TH))
1529 BETUS=0.5*(1.+SQRT(1.+EPST*UH/SH))
1530 BEUTS=BESTU
1531 BETSU=BEUST
1532 BESUT=BETUS
1533 W3STUR=PYI3AU_HIJING(BESTU,EPSH,1)-PYI3AU_HIJING(BESTU,EPSS,1)-
1534 & PYI3AU_HIJING(BESTU,EPSU,1)
1535 W3STUI=PYI3AU_HIJING(BESTU,EPSH,2)-PYI3AU_HIJING(BESTU,EPSS,2)-
1536 & PYI3AU_HIJING(BESTU,EPSU,2)
1537 W3SUTR=PYI3AU_HIJING(BESUT,EPSH,1)-PYI3AU_HIJING(BESUT,EPSS,1)-
1538 & PYI3AU_HIJING(BESUT,EPST,1)
1539 W3SUTI=PYI3AU_HIJING(BESUT,EPSH,2)-PYI3AU_HIJING(BESUT,EPSS,2)-
1540 & PYI3AU_HIJING(BESUT,EPST,2)
1541 W3TSUR=PYI3AU_HIJING(BETSU,EPSH,1)-PYI3AU_HIJING(BETSU,EPST,1)-
1542 & PYI3AU_HIJING(BETSU,EPSU,1)
1543 W3TSUI=PYI3AU_HIJING(BETSU,EPSH,2)-PYI3AU_HIJING(BETSU,EPST,2)-
1544 & PYI3AU_HIJING(BETSU,EPSU,2)
1545 W3TUSR=PYI3AU_HIJING(BETUS,EPSH,1)-PYI3AU_HIJING(BETUS,EPST,1)-
1546 & PYI3AU_HIJING(BETUS,EPSS,1)
1547 W3TUSI=PYI3AU_HIJING(BETUS,EPSH,2)-PYI3AU_HIJING(BETUS,EPST,2)-
1548 & PYI3AU_HIJING(BETUS,EPSS,2)
1549 W3USTR=PYI3AU_HIJING(BEUST,EPSH,1)-PYI3AU_HIJING(BEUST,EPSU,1)-
1550 & PYI3AU_HIJING(BEUST,EPST,1)
1551 W3USTI=PYI3AU_HIJING(BEUST,EPSH,2)-PYI3AU_HIJING(BEUST,EPSU,2)-
1552 & PYI3AU_HIJING(BEUST,EPST,2)
1553 W3UTSR=PYI3AU_HIJING(BEUTS,EPSH,1)-PYI3AU_HIJING(BEUTS,EPSU,1)-
1554 & PYI3AU_HIJING(BEUTS,EPSS,1)
1555 W3UTSI=PYI3AU_HIJING(BEUTS,EPSH,2)-PYI3AU_HIJING(BEUTS,EPSU,2)-
1556 & PYI3AU_HIJING(BEUTS,EPSS,2)
1557 B2STUR=SQMQ/SQMH**2*(SH*(UH-SH)/(SH+UH)+2.*TH*UH*(UH+2.*SH)/
1558 & (SH+UH)**2*(PYW1AU_HIJING(EPST,1)-PYW1AU_HIJING(EPSH,1))
1559 $ +(SQMQ-SH/4.)*(0.5*PYW2AU_HIJING(EPSS,1)+0.5
1560 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPST,1)+W3STUR)+SH**2
1561 $ *(2.*SQMQ/(SH+UH)**2-0.5/(SH+UH))*(PYW2AU_HIJING(EPST,1)
1562 $ -PYW2AU_HIJING(EPSH,1))+0.5*TH*UH/SH*(PYW2AU_HIJING(EPSH,1)
1563 $ -2.*PYW2AU_HIJING(EPST,1))+0.125*(SH-12.*SQMQ-4.*TH*UH/SH)
1564 $ *W3TSUR)
1565 B2STUI=SQMQ/SQMH**2*(2.*TH*UH*(UH+2.*SH)/(SH+UH)**2*
1566 & (PYW1AU_HIJING(EPST,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-SH/4.)*
1567 & (0.5*PYW2AU_HIJING(EPSS,2)+0.5*PYW2AU_HIJING(EPSH,2)
1568 $ -PYW2AU_HIJING(EPST,2)+W3STUI)+SH**2*(2.*SQMQ/(SH+UH)**2-0
1569 $ .5/(SH+UH))*(PYW2AU_HIJING(EPST,2)-PYW2AU_HIJING(EPSH,2))+0
1570 $ .5*TH*UH/SH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPST,2)
1571 $ )+0.125*(SH-12.*SQMQ-4.*TH*UH/SH)*W3TSUI)
1572 B2SUTR=SQMQ/SQMH**2*(SH*(TH-SH)/(SH+TH)+2.*UH*TH*(TH+2.*SH)/
1573 & (SH+TH)**2*(PYW1AU_HIJING(EPSU,1)-PYW1AU_HIJING(EPSH,1))
1574 $ +(SQMQ-SH/4.)*(0.5*PYW2AU_HIJING(EPSS,1)+0.5
1575 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPSU,1)+W3SUTR)+SH**2
1576 $ *(2.*SQMQ/(SH+TH)**2-0.5/(SH+TH))*(PYW2AU_HIJING(EPSU,1)
1577 $ -PYW2AU_HIJING(EPSH,1))+0.5*UH*TH/SH*(PYW2AU_HIJING(EPSH,1)
1578 $ -2.*PYW2AU_HIJING(EPSU,1))+0.125*(SH-12.*SQMQ-4.*UH*TH/SH)
1579 $ *W3USTR)
1580 B2SUTI=SQMQ/SQMH**2*(2.*UH*TH*(TH+2.*SH)/(SH+TH)**2*
1581 & (PYW1AU_HIJING(EPSU,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-SH/4.)*
1582 & (0.5*PYW2AU_HIJING(EPSS,2)+0.5*PYW2AU_HIJING(EPSH,2)
1583 $ -PYW2AU_HIJING(EPSU,2)+W3SUTI)+SH**2*(2.*SQMQ/(SH+TH)**2-0
1584 $ .5/(SH+TH))*(PYW2AU_HIJING(EPSU,2)-PYW2AU_HIJING(EPSH,2))+0
1585 $ .5*UH*TH/SH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPSU,2)
1586 $ )+0.125*(SH-12.*SQMQ-4.*UH*TH/SH)*W3USTI)
1587 B2TSUR=SQMQ/SQMH**2*(TH*(UH-TH)/(TH+UH)+2.*SH*UH*(UH+2.*TH)/
1588 & (TH+UH)**2*(PYW1AU_HIJING(EPSS,1)-PYW1AU_HIJING(EPSH,1))
1589 $ +(SQMQ-TH/4.)*(0.5*PYW2AU_HIJING(EPST,1)+0.5
1590 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPSS,1)+W3TSUR)+TH**2
1591 $ *(2.*SQMQ/(TH+UH)**2-0.5/(TH+UH))*(PYW2AU_HIJING(EPSS,1)
1592 $ -PYW2AU_HIJING(EPSH,1))+0.5*SH*UH/TH*(PYW2AU_HIJING(EPSH,1)
1593 $ -2.*PYW2AU_HIJING(EPSS,1))+0.125*(TH-12.*SQMQ-4.*SH*UH/TH)
1594 $ *W3STUR)
1595 B2TSUI=SQMQ/SQMH**2*(2.*SH*UH*(UH+2.*TH)/(TH+UH)**2*
1596 & (PYW1AU_HIJING(EPSS,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-TH/4.)*
1597 & (0.5*PYW2AU_HIJING(EPST,2)+0.5*PYW2AU_HIJING(EPSH,2)
1598 $ -PYW2AU_HIJING(EPSS,2)+W3TSUI)+TH**2*(2.*SQMQ/(TH+UH)**2-0
1599 $ .5/(TH+UH))*(PYW2AU_HIJING(EPSS,2)-PYW2AU_HIJING(EPSH,2))+0
1600 $ .5*SH*UH/TH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPSS,2)
1601 $ )+0.125*(TH-12.*SQMQ-4.*SH*UH/TH)*W3STUI)
1602 B2TUSR=SQMQ/SQMH**2*(TH*(SH-TH)/(TH+SH)+2.*UH*SH*(SH+2.*TH)/
1603 & (TH+SH)**2*(PYW1AU_HIJING(EPSU,1)-PYW1AU_HIJING(EPSH,1))
1604 $ +(SQMQ-TH/4.)*(0.5*PYW2AU_HIJING(EPST,1)+0.5
1605 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPSU,1)+W3TUSR)+TH**2
1606 $ *(2.*SQMQ/(TH+SH)**2-0.5/(TH+SH))*(PYW2AU_HIJING(EPSU,1)
1607 $ -PYW2AU_HIJING(EPSH,1))+0.5*UH*SH/TH*(PYW2AU_HIJING(EPSH,1)
1608 $ -2.*PYW2AU_HIJING(EPSU,1))+0.125*(TH-12.*SQMQ-4.*UH*SH/TH)
1609 $ *W3UTSR)
1610 B2TUSI=SQMQ/SQMH**2*(2.*UH*SH*(SH+2.*TH)/(TH+SH)**2*
1611 & (PYW1AU_HIJING(EPSU,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-TH/4.)*
1612 & (0.5*PYW2AU_HIJING(EPST,2)+0.5*PYW2AU_HIJING(EPSH,2)
1613 $ -PYW2AU_HIJING(EPSU,2)+W3TUSI)+TH**2*(2.*SQMQ/(TH+SH)**2-0
1614 $ .5/(TH+SH))*(PYW2AU_HIJING(EPSU,2)-PYW2AU_HIJING(EPSH,2))+0
1615 $ .5*UH*SH/TH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPSU,2)
1616 $ )+0.125*(TH-12.*SQMQ-4.*UH*SH/TH)*W3UTSI)
1617 B2USTR=SQMQ/SQMH**2*(UH*(TH-UH)/(UH+TH)+2.*SH*TH*(TH+2.*UH)/
1618 & (UH+TH)**2*(PYW1AU_HIJING(EPSS,1)-PYW1AU_HIJING(EPSH,1))
1619 $ +(SQMQ-UH/4.)*(0.5*PYW2AU_HIJING(EPSU,1)+0.5
1620 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPSS,1)+W3USTR)+UH**2
1621 $ *(2.*SQMQ/(UH+TH)**2-0.5/(UH+TH))*(PYW2AU_HIJING(EPSS,1)
1622 $ -PYW2AU_HIJING(EPSH,1))+0.5*SH*TH/UH*(PYW2AU_HIJING(EPSH,1)
1623 $ -2.*PYW2AU_HIJING(EPSS,1))+0.125*(UH-12.*SQMQ-4.*SH*TH/UH)
1624 $ *W3SUTR)
1625 B2USTI=SQMQ/SQMH**2*(2.*SH*TH*(TH+2.*UH)/(UH+TH)**2*
1626 & (PYW1AU_HIJING(EPSS,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-UH/4.)*
1627 & (0.5*PYW2AU_HIJING(EPSU,2)+0.5*PYW2AU_HIJING(EPSH,2)
1628 $ -PYW2AU_HIJING(EPSS,2)+W3USTI)+UH**2*(2.*SQMQ/(UH+TH)**2-0
1629 $ .5/(UH+TH))*(PYW2AU_HIJING(EPSS,2)-PYW2AU_HIJING(EPSH,2))+0
1630 $ .5*SH*TH/UH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPSS,2)
1631 $ )+0.125*(UH-12.*SQMQ-4.*SH*TH/UH)*W3SUTI)
1632 B2UTSR=SQMQ/SQMH**2*(UH*(SH-UH)/(UH+SH)+2.*TH*SH*(SH+2.*UH)/
1633 & (UH+SH)**2*(PYW1AU_HIJING(EPST,1)-PYW1AU_HIJING(EPSH,1))
1634 $ +(SQMQ-UH/4.)*(0.5*PYW2AU_HIJING(EPSU,1)+0.5
1635 $ *PYW2AU_HIJING(EPSH,1)-PYW2AU_HIJING(EPST,1)+W3UTSR)+UH**2
1636 $ *(2.*SQMQ/(UH+SH)**2-0.5/(UH+SH))*(PYW2AU_HIJING(EPST,1)
1637 $ -PYW2AU_HIJING(EPSH,1))+0.5*TH*SH/UH*(PYW2AU_HIJING(EPSH,1)
1638 $ -2.*PYW2AU_HIJING(EPST,1))+0.125*(UH-12.*SQMQ-4.*TH*SH/UH)
1639 $ *W3TUSR)
1640 B2UTSI=SQMQ/SQMH**2*(2.*TH*SH*(SH+2.*UH)/(UH+SH)**2*
1641 & (PYW1AU_HIJING(EPST,2)-PYW1AU_HIJING(EPSH,2))+(SQMQ-UH/4.)*
1642 & (0.5*PYW2AU_HIJING(EPSU,2)+0.5*PYW2AU_HIJING(EPSH,2)
1643 $ -PYW2AU_HIJING(EPST,2)+W3UTSI)+UH**2*(2.*SQMQ/(UH+SH)**2-0
1644 $ .5/(UH+SH))*(PYW2AU_HIJING(EPST,2)-PYW2AU_HIJING(EPSH,2))+0
1645 $ .5*TH*SH/UH*(PYW2AU_HIJING(EPSH,2)-2.*PYW2AU_HIJING(EPST,2)
1646 $ )+0.125*(UH-12.*SQMQ-4.*TH*SH/UH)*W3TUSI)
1647 B4STUR=SQMQ/SQMH*(-2./3.+(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPSS,1
1648 $ )-PYW2AU_HIJING(EPSH,1)+W3STUR))
1649 B4STUI=SQMQ/SQMH*(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPSS,2)-
1650 & PYW2AU_HIJING(EPSH,2)+W3STUI)
1651 B4TUSR=SQMQ/SQMH*(-2./3.+(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPST,1
1652 $ )-PYW2AU_HIJING(EPSH,1)+W3TUSR))
1653 B4TUSI=SQMQ/SQMH*(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPST,2)-
1654 & PYW2AU_HIJING(EPSH,2)+W3TUSI)
1655 B4USTR=SQMQ/SQMH*(-2./3.+(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPSU,1
1656 $ )-PYW2AU_HIJING(EPSH,1)+W3USTR))
1657 B4USTI=SQMQ/SQMH*(SQMQ/SQMH-1./4.)*(PYW2AU_HIJING(EPSU,2)-
1658 & PYW2AU_HIJING(EPSH,2)+W3USTI)
1659 A2STUR=A2STUR+B2STUR+B2SUTR
1660 A2STUI=A2STUI+B2STUI+B2SUTI
1661 A2USTR=A2USTR+B2USTR+B2UTSR
1662 A2USTI=A2USTI+B2USTI+B2UTSI
1663 A2TUSR=A2TUSR+B2TUSR+B2TSUR
1664 A2TUSI=A2TUSI+B2TUSI+B2TSUI
1665 A4STUR=A4STUR+B4STUR+B4USTR+B4TUSR
1666 A4STUI=A4STUI+B4STUI+B4USTI+B4TUSI
1667 760 CONTINUE
1668 FACGH=COMFAC*FACA*3./(128.*PARU(1)**2)*AEM/XW*AS**3*
1669 & SQMH/SQMW*SQMH**3/(SH*TH*UH)*(A2STUR**2+A2STUI**2+A2USTR**2+
1670 & A2USTI**2+A2TUSR**2+A2TUSI**2+A4STUR**2+A4STUI**2)
1671 FACGH=FACGH*WIDS(25,2)
1672 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 770
1673 NCHN=NCHN+1
1674 ISIG(NCHN,1)=21
1675 ISIG(NCHN,2)=21
1676 ISIG(NCHN,3)=1
1677 SIGH(NCHN)=FACGH
1678 770 CONTINUE
1679
1680 ELSEIF(ISUB.EQ.114) THEN
1681C...g + g -> gamma + gamma.
1682 ASRE=0.
1683 ASIM=0.
1684 DO 780 I=1,2*MSTP(1)
1685 EI=KCHG(IABS(I),1)/3.
1686 SQMQ=PMAS(I,1)**2
1687 EPSS=4.*SQMQ/SH
1688 EPST=4.*SQMQ/TH
1689 EPSU=4.*SQMQ/UH
1690 IF(EPSS+ABS(EPST)+ABS(EPSU).LT.3.E-6) THEN
1691 A0STUR=1.+(TH-UH)/SH*LOG(TH/UH)+0.5*(TH2+UH2)/SH2*
1692 & (LOG(TH/UH)**2+PARU(1)**2)
1693 A0STUI=0.
1694 A0TSUR=1.+(SH-UH)/TH*LOG(-SH/UH)+0.5*(SH2+UH2)/TH2*
1695 & LOG(-SH/UH)**2
1696 A0TSUI=-PARU(1)*((SH-UH)/TH+(SH2+UH2)/TH2*LOG(-SH/UH))
1697 A0UTSR=1.+(TH-SH)/UH*LOG(-TH/SH)+0.5*(TH2+SH2)/UH2*
1698 & LOG(-TH/SH)**2
1699 A0UTSI=PARU(1)*((TH-SH)/UH+(TH2+SH2)/UH2*LOG(-TH/SH))
1700 A1STUR=-1.
1701 A1STUI=0.
1702 A2STUR=-1.
1703 A2STUI=0.
1704 ELSE
1705 BESTU=0.5*(1.+SQRT(1.+EPSS*TH/UH))
1706 BEUST=0.5*(1.+SQRT(1.+EPSU*SH/TH))
1707 BETUS=0.5*(1.+SQRT(1.+EPST*UH/SH))
1708 BEUTS=BESTU
1709 BETSU=BEUST
1710 BESUT=BETUS
1711 A0STUR=1.+(1.+2.*TH/SH)*PYW1AU_HIJING(EPST,1)+(1.+2.*UH/SH)*
1712 & PYW1AU_HIJING(EPSU,1)+0.5*((TH2+UH2)/SH2-EPSS)
1713 $ *(PYW2AU_HIJING(EPST,1)+PYW2AU_HIJING(EPSU,1))-0.25*EPST
1714 $ *(1.-0.5*EPSS)*(PYI3AU_HIJING(BESUT,EPSS,1)
1715 $ +PYI3AU_HIJING(BESUT,EPST,1))-0.25*EPSU*(1.-0.5*EPSS)
1716 $ *(PYI3AU_HIJING(BESTU,EPSS,1)+PYI3AU_HIJING(BESTU,EPSU,1)
1717 $ )+0.25*(-2.*(TH2+UH2)/SH2+4.*EPSS+EPST+EPSU+0.5*EPST*EPSU
1718 $ )*(PYI3AU_HIJING(BETSU,EPST,1)+PYI3AU_HIJING(BETSU,EPSU,1
1719 $ ))
1720 A0STUI=(1.+2.*TH/SH)*PYW1AU_HIJING(EPST,2)+(1.+2.*UH/SH)*
1721 & PYW1AU_HIJING(EPSU,2)+0.5*((TH2+UH2)/SH2-EPSS)
1722 $ *(PYW2AU_HIJING(EPST,2)+PYW2AU_HIJING(EPSU,2))-0.25*EPST
1723 $ *(1.-0.5*EPSS)*(PYI3AU_HIJING(BESUT,EPSS,2)
1724 $ +PYI3AU_HIJING(BESUT,EPST,2))-0.25*EPSU*(1.-0.5*EPSS)
1725 $ *(PYI3AU_HIJING(BESTU,EPSS,2)+PYI3AU_HIJING(BESTU,EPSU,2)
1726 $ )+0.25*(-2.*(TH2+UH2)/SH2+4.*EPSS+EPST+EPSU+0.5*EPST*EPSU
1727 $ )*(PYI3AU_HIJING(BETSU,EPST,2)+PYI3AU_HIJING(BETSU,EPSU,2
1728 $ ))
1729 A0TSUR=1.+(1.+2.*SH/TH)*PYW1AU_HIJING(EPSS,1)+(1.+2.*UH/TH)*
1730 & PYW1AU_HIJING(EPSU,1)+0.5*((SH2+UH2)/TH2-EPST)
1731 $ *(PYW2AU_HIJING(EPSS,1)+PYW2AU_HIJING(EPSU,1))-0.25*EPSS
1732 $ *(1.-0.5*EPST)*(PYI3AU_HIJING(BETUS,EPST,1)
1733 $ +PYI3AU_HIJING(BETUS,EPSS,1))-0.25*EPSU*(1.-0.5*EPST)
1734 $ *(PYI3AU_HIJING(BETSU,EPST,1)+PYI3AU_HIJING(BETSU,EPSU,1)
1735 $ )+0.25*(-2.*(SH2+UH2)/TH2+4.*EPST+EPSS+EPSU+0.5*EPSS*EPSU
1736 $ )*(PYI3AU_HIJING(BESTU,EPSS,1)+PYI3AU_HIJING(BESTU,EPSU,1
1737 $ ))
1738 A0TSUI=(1.+2.*SH/TH)*PYW1AU_HIJING(EPSS,2)+(1.+2.*UH/TH)*
1739 & PYW1AU_HIJING(EPSU,2)+0.5*((SH2+UH2)/TH2-EPST)
1740 $ *(PYW2AU_HIJING(EPSS,2)+PYW2AU_HIJING(EPSU,2))-0.25*EPSS
1741 $ *(1.-0.5*EPST)*(PYI3AU_HIJING(BETUS,EPST,2)
1742 $ +PYI3AU_HIJING(BETUS,EPSS,2))-0.25*EPSU*(1.-0.5*EPST)
1743 $ *(PYI3AU_HIJING(BETSU,EPST,2)+PYI3AU_HIJING(BETSU,EPSU,2)
1744 $ )+0.25*(-2.*(SH2+UH2)/TH2+4.*EPST+EPSS+EPSU+0.5*EPSS*EPSU
1745 $ )*(PYI3AU_HIJING(BESTU,EPSS,2)+PYI3AU_HIJING(BESTU,EPSU,2
1746 $ ))
1747 A0UTSR=1.+(1.+2.*TH/UH)*PYW1AU_HIJING(EPST,1)+(1.+2.*SH/UH)*
1748 & PYW1AU_HIJING(EPSS,1)+0.5*((TH2+SH2)/UH2-EPSU)
1749 $ *(PYW2AU_HIJING(EPST,1)+PYW2AU_HIJING(EPSS,1))-0.25*EPST
1750 $ *(1.-0.5*EPSU)*(PYI3AU_HIJING(BEUST,EPSU,1)
1751 $ +PYI3AU_HIJING(BEUST,EPST,1))-0.25*EPSS*(1.-0.5*EPSU)
1752 $ *(PYI3AU_HIJING(BEUTS,EPSU,1)+PYI3AU_HIJING(BEUTS,EPSS,1)
1753 $ )+0.25*(-2.*(TH2+SH2)/UH2+4.*EPSU+EPST+EPSS+0.5*EPST*EPSS
1754 $ )*(PYI3AU_HIJING(BETUS,EPST,1)+PYI3AU_HIJING(BETUS,EPSS,1
1755 $ ))
1756 A0UTSI=(1.+2.*TH/UH)*PYW1AU_HIJING(EPST,2)+(1.+2.*SH/UH)*
1757 & PYW1AU_HIJING(EPSS,2)+0.5*((TH2+SH2)/UH2-EPSU)
1758 $ *(PYW2AU_HIJING(EPST,2)+PYW2AU_HIJING(EPSS,2))-0.25*EPST
1759 $ *(1.-0.5*EPSU)*(PYI3AU_HIJING(BEUST,EPSU,2)
1760 $ +PYI3AU_HIJING(BEUST,EPST,2))-0.25*EPSS*(1.-0.5*EPSU)
1761 $ *(PYI3AU_HIJING(BEUTS,EPSU,2)+PYI3AU_HIJING(BEUTS,EPSS,2)
1762 $ )+0.25*(-2.*(TH2+SH2)/UH2+4.*EPSU+EPST+EPSS+0.5*EPST*EPSS
1763 $ )*(PYI3AU_HIJING(BETUS,EPST,2)+PYI3AU_HIJING(BETUS,EPSS,2
1764 $ ))
1765 A1STUR=-1.-0.25*(EPSS+EPST+EPSU)*(PYW2AU_HIJING(EPSS,1)+
1766 & PYW2AU_HIJING(EPST,1)+PYW2AU_HIJING(EPSU,1))+0.25*(EPSU+0
1767 $ .5*EPSS*EPST)*(PYI3AU_HIJING(BESUT,EPSS,1)
1768 $ +PYI3AU_HIJING(BESUT,EPST,1))+0.25*(EPST+0.5*EPSS*EPSU)
1769 $ *(PYI3AU_HIJING(BESTU,EPSS,1)+PYI3AU_HIJING(BESTU,EPSU,1)
1770 $ )+0.25*(EPSS+0.5*EPST*EPSU)*(PYI3AU_HIJING(BETSU,EPST,1)
1771 $ +PYI3AU_HIJING(BETSU,EPSU,1))
1772 A1STUI=-0.25*(EPSS+EPST+EPSU)*(PYW2AU_HIJING(EPSS,2)
1773 $ +PYW2AU_HIJING(EPST,2)+PYW2AU_HIJING(EPSU,2))+0.25*(EPSU
1774 $ +0.5*EPSS*EPST)*(PYI3AU_HIJING(BESUT,EPSS,2)
1775 $ +PYI3AU_HIJING(BESUT,EPST,2))+0.25*(EPST+0.5*EPSS*EPSU)
1776 $ *(PYI3AU_HIJING(BESTU,EPSS,2)+PYI3AU_HIJING(BESTU,EPSU,2)
1777 $ )+0.25*(EPSS+0.5*EPST*EPSU)*(PYI3AU_HIJING(BETSU,EPST,2)
1778 $ +PYI3AU_HIJING(BETSU,EPSU,2))
1779 A2STUR=-1.+0.125*EPSS*EPST*(PYI3AU_HIJING(BESUT,EPSS,1)+
1780 & PYI3AU_HIJING(BESUT,EPST,1))+0.125*EPSS*EPSU
1781 $ *(PYI3AU_HIJING(BESTU,EPSS,1)+PYI3AU_HIJING(BESTU,EPSU,1)
1782 $ )+0.125*EPST*EPSU*(PYI3AU_HIJING(BETSU,EPST,1)
1783 $ +PYI3AU_HIJING(BETSU,EPSU,1))
1784 A2STUI=0.125*EPSS*EPST*(PYI3AU_HIJING(BESUT,EPSS,2)+
1785 & PYI3AU_HIJING(BESUT,EPST,2))+0.125*EPSS*EPSU
1786 $ *(PYI3AU_HIJING(BESTU,EPSS,2)+PYI3AU_HIJING(BESTU,EPSU,2)
1787 $ )+0.125*EPST*EPSU*(PYI3AU_HIJING(BETSU,EPST,2)
1788 $ +PYI3AU_HIJING(BETSU,EPSU,2))
1789 ENDIF
1790 ASRE=ASRE+EI**2*(A0STUR+A0TSUR+A0UTSR+4.*A1STUR+A2STUR)
1791 ASIM=ASIM+EI**2*(A0STUI+A0TSUI+A0UTSI+4.*A1STUI+A2STUI)
1792 780 CONTINUE
1793 FACGG=COMFAC*FACA/(8.*PARU(1)**2)*AS**2*AEM**2*(ASRE**2+ASIM**2)
1794 IF(KFAC(1,21)*KFAC(2,21).EQ.0) GOTO 790
1795 NCHN=NCHN+1
1796 ISIG(NCHN,1)=21
1797 ISIG(NCHN,2)=21
1798 ISIG(NCHN,3)=1
1799 SIGH(NCHN)=FACGG
1800 790 CONTINUE
1801
1802 ELSEIF(ISUB.EQ.115) THEN
1803C...g + g -> gamma + Z0.
1804
1805 ELSEIF(ISUB.EQ.116) THEN
1806C...g + g -> Z0 + Z0.
1807
1808 ELSEIF(ISUB.EQ.117) THEN
1809C...g + g -> W+ + W-.
1810
1811 ENDIF
1812
1813C...G: 2 -> 3, tree diagrams.
1814
1815 ELSEIF(ISUB.LE.140) THEN
1816 IF(ISUB.EQ.121) THEN
1817C...g + g -> f + fb + H0.
1818
1819 ENDIF
1820
1821C...H: 2 -> 1, tree diagrams, non-standard model processes.
1822
1823 ELSEIF(ISUB.LE.160) THEN
1824 IF(ISUB.EQ.141) THEN
1825C...f + fb -> gamma*/Z0/Z'0.
1826 MINT(61)=2
1827 CALL PYWIDT_HIJING(32,SQRT(SH),WDTP,WDTE)
1828 FACZP=COMFAC*AEM**2*4./9.
1829 DO 800 I=MINA,MAXA
1830 IF(I.EQ.0.OR.KFAC(1,I)*KFAC(2,-I).EQ.0) GOTO 800
1831 EI=KCHG(IABS(I),1)/3.
1832 AI=SIGN(1.,EI)
1833 VI=AI-4.*EI*XW
1834 API=SIGN(1.,EI)
1835 VPI=API-4.*EI*XW
1836 NCHN=NCHN+1
1837 ISIG(NCHN,1)=I
1838 ISIG(NCHN,2)=-I
1839 ISIG(NCHN,3)=1
1840 SIGH(NCHN)=FACZP*(EI**2*VINT(111)+EI*VI/(8.*XW*(1.-XW))*
1841 & SH*(SH-SQMZ)/((SH-SQMZ)**2+GMMZ**2)*VINT(112)+EI*VPI/(8.*XW*
1842 & (1.-XW))*SH*(SH-SQMZP)/((SH-SQMZP)**2+GMMZP**2)*VINT(113)+
1843 & (VI**2+AI**2)/(16.*XW*(1.-XW))**2*SH2/((SH-SQMZ)**2+GMMZ**2)*
1844 & VINT(114)+2.*(VI*VPI+AI*API)/(16.*XW*(1.-XW))**2*SH2*
1845 & ((SH-SQMZ)*(SH-SQMZP)+GMMZ*GMMZP)/(((SH-SQMZ)**2+GMMZ**2)*
1846 & ((SH-SQMZP)**2+GMMZP**2))*VINT(115)+(VPI**2+API**2)/
1847 & (16.*XW*(1.-XW))**2*SH2/((SH-SQMZP)**2+GMMZP**2)*VINT(116))
1848 800 CONTINUE
1849
1850 ELSEIF(ISUB.EQ.142) THEN
1851C...f + fb' -> H+/-.
1852 CALL PYWIDT_HIJING(37,SQRT(SH),WDTP,WDTE)
1853 FHC=COMFAC*(AEM/XW)**2*1./48.*(SH/SQMW)**2*SH2/
1854 & ((SH-SQMHC)**2+GMMHC**2)
1855C'''No construction yet for leptons
1856 DO 840 I=1,MSTP(54)/2
1857 IL=2*I-1
1858 IU=2*I
1859 RMQL=PMAS(IL,1)**2/SH
1860 RMQU=PMAS(IU,1)**2/SH
1861 FACHC=FHC*((RMQL*PARU(121)+RMQU/PARU(121))*(1.-RMQL-RMQU)-
1862 & 4.*RMQL*RMQU)/SQRT(MAX(0.,(1.-RMQL-RMQU)**2-4.*RMQL*RMQU))
1863 IF(KFAC(1,IL)*KFAC(2,-IU).EQ.0) GOTO 810
1864 KCHHC=(KCHG(IL,1)-KCHG(IU,1))/3
1865 NCHN=NCHN+1
1866 ISIG(NCHN,1)=IL
1867 ISIG(NCHN,2)=-IU
1868 ISIG(NCHN,3)=1
1869 SIGH(NCHN)=FACHC*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1870 810 IF(KFAC(1,-IL)*KFAC(2,IU).EQ.0) GOTO 820
1871 KCHHC=(-KCHG(IL,1)+KCHG(IU,1))/3
1872 NCHN=NCHN+1
1873 ISIG(NCHN,1)=-IL
1874 ISIG(NCHN,2)=IU
1875 ISIG(NCHN,3)=1
1876 SIGH(NCHN)=FACHC*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1877 820 IF(KFAC(1,IU)*KFAC(2,-IL).EQ.0) GOTO 830
1878 KCHHC=(KCHG(IU,1)-KCHG(IL,1))/3
1879 NCHN=NCHN+1
1880 ISIG(NCHN,1)=IU
1881 ISIG(NCHN,2)=-IL
1882 ISIG(NCHN,3)=1
1883 SIGH(NCHN)=FACHC*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1884 830 IF(KFAC(1,-IU)*KFAC(2,IL).EQ.0) GOTO 840
1885 KCHHC=(-KCHG(IU,1)+KCHG(IL,1))/3
1886 NCHN=NCHN+1
1887 ISIG(NCHN,1)=-IU
1888 ISIG(NCHN,2)=IL
1889 ISIG(NCHN,3)=1
1890 SIGH(NCHN)=FACHC*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1891 840 CONTINUE
1892
1893 ELSEIF(ISUB.EQ.143) THEN
1894C...f + fb -> R.
1895 CALL PYWIDT_HIJING(40,SQRT(SH),WDTP,WDTE)
1896 FACR=COMFAC*(AEM/XW)**2*1./9.*SH2/((SH-SQMR)**2+GMMR**2)
1897 DO 860 I=MIN1,MAX1
1898 IF(I.EQ.0.OR.KFAC(1,I).EQ.0) GOTO 860
1899 IA=IABS(I)
1900 DO 850 J=MIN2,MAX2
1901 IF(J.EQ.0.OR.KFAC(2,J).EQ.0) GOTO 850
1902 JA=IABS(J)
1903 IF(I*J.GT.0.OR.IABS(IA-JA).NE.2) GOTO 850
1904 NCHN=NCHN+1
1905 ISIG(NCHN,1)=I
1906 ISIG(NCHN,2)=J
1907 ISIG(NCHN,3)=1
1908 SIGH(NCHN)=FACR*(WDTE(0,1)+WDTE(0,(10-(I+J))/4)+WDTE(0,4))
1909 850 CONTINUE
1910 860 CONTINUE
1911
1912 ENDIF
1913
1914C...I: 2 -> 2, tree diagrams, non-standard model processes.
1915
1916 ELSE
1917 IF(ISUB.EQ.161) THEN
1918C...f + g -> f' + H+/- (q + g -> q' + H+/- only).
1919 FHCQ=COMFAC*FACA*AS*AEM/XW*1./24
1920 DO 900 I=1,MSTP(54)
1921 IU=I+MOD(I,2)
1922 SQMQ=PMAS(IU,1)**2
1923 FACHCQ=FHCQ/PARU(121)*SQMQ/SQMW*(SH/(SQMQ-UH)+
1924 & 2.*SQMQ*(SQMHC-UH)/(SQMQ-UH)**2+(SQMQ-UH)/SH+
1925 & 2.*SQMQ/(SQMQ-UH)+2.*(SQMHC-UH)/(SQMQ-UH)*(SQMHC-SQMQ-SH)/SH)
1926 IF(KFAC(1,-I)*KFAC(2,21).EQ.0) GOTO 870
1927 KCHHC=ISIGN(1,-KCHG(I,1))
1928 NCHN=NCHN+1
1929 ISIG(NCHN,1)=-I
1930 ISIG(NCHN,2)=21
1931 ISIG(NCHN,3)=1
1932 SIGH(NCHN)=FACHCQ*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1933 870 IF(KFAC(1,I)*KFAC(2,21).EQ.0) GOTO 880
1934 KCHHC=ISIGN(1,KCHG(I,1))
1935 NCHN=NCHN+1
1936 ISIG(NCHN,1)=I
1937 ISIG(NCHN,2)=21
1938 ISIG(NCHN,3)=1
1939 SIGH(NCHN)=FACHCQ*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1940 880 IF(KFAC(1,21)*KFAC(2,-I).EQ.0) GOTO 890
1941 KCHHC=ISIGN(1,-KCHG(I,1))
1942 NCHN=NCHN+1
1943 ISIG(NCHN,1)=21
1944 ISIG(NCHN,2)=-I
1945 ISIG(NCHN,3)=1
1946 SIGH(NCHN)=FACHCQ*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1947 890 IF(KFAC(1,21)*KFAC(2,I).EQ.0) GOTO 900
1948 KCHHC=ISIGN(1,KCHG(I,1))
1949 NCHN=NCHN+1
1950 ISIG(NCHN,1)=21
1951 ISIG(NCHN,2)=I
1952 ISIG(NCHN,3)=1
1953 SIGH(NCHN)=FACHCQ*(WDTE(0,1)+WDTE(0,(5-KCHHC)/2)+WDTE(0,4))
1954 900 CONTINUE
1955
1956 ENDIF
1957 ENDIF
1958
1959C...Multiply with structure functions.
1960 IF(ISUB.LE.90.OR.ISUB.GE.96) THEN
1961 DO 910 ICHN=1,NCHN
1962 IF(MINT(41).EQ.2) THEN
1963 KFL1=ISIG(ICHN,1)
1964 IF(KFL1.EQ.21) KFL1=0
1965 SIGH(ICHN)=SIGH(ICHN)*XSFX(1,KFL1)
1966 ENDIF
1967 IF(MINT(42).EQ.2) THEN
1968 KFL2=ISIG(ICHN,2)
1969 IF(KFL2.EQ.21) KFL2=0
1970 SIGH(ICHN)=SIGH(ICHN)*XSFX(2,KFL2)
1971 ENDIF
1972 910 SIGS=SIGS+SIGH(ICHN)
1973 ENDIF
1974
1975 RETURN
1976 END