4 SUBROUTINE luxdif(NC,NJET,KFL,ECM,CHI,THE,PHI)
7 common/lujets/
n,
k(9000,5),
p(9000,5),
v(9000,5)
9 common/ludat1/mstu(200),paru(200),mstj(200),parj(200)
11 common/ludat2/kchg(500,3),pmas(500,4),parf(2000),vckm(4,4)
16 poll=1.-parj(131)*parj(132)
17 pold=parj(132)-parj(131)
18 IF(mstj(102).LE.1.OR.mstj(109).EQ.1)
THEN
26 sff=1./(16.*paru(102)*(1.-paru(102)))
27 sfw=ecm**4/((ecm**2-parj(123)**2)**2+(parj(123)*parj(124))**2)
28 sfi=sfw*(1.-(parj(123)/ecm)**2)
33 hf1=qf**2*poll-2.*qf*vf*sfi*sff*(ve*poll-ae*pold)+
34 & (vf**2+af**2)*sfw*sff**2*((ve**2+ae**2)*poll-2.*ve*ae*pold)
35 hf2=-2.*qf*af*sfi*sff*(ae*poll-ve*pold)+2.*vf*af*sfw*sff**2*
36 & (2.*ve*ae*poll-(ve**2+ae**2)*pold)
37 hf3=parj(133)**2*(qf**2-2.*qf*vf*sfi*sff*ve+(vf**2+af**2)*
38 & sfw*sff**2*(ve**2-ae**2))
39 hf4=-parj(133)**2*2.*qf*vf*sfw*(parj(123)*parj(124)/ecm**2)*
46 IF(mstj(103).GE.4.AND.iabs(mstj(101)).LE.1.AND.mstj(102).LE.1.AND.
47 &mstj(109).NE.1) qme=(2.*
ulmass(kfl)/ecm)**2
50 sigl=2.*qme*sqrt(1.-qme)
62 ecmr=
p(nc+1,4)+
p(nc+4,4)+sqrt((
p(nc+2,1)+
p(nc+3,1))**2+
63 & (
p(nc+2,2)+
p(nc+3,2))**2+(
p(nc+2,3)+
p(nc+3,3))**2)
70 ct12=(x1*x2-2.*x1-2.*x2+2.+qme)/sqrt((x1**2-qme)*(x2**2-qme))
72 IF(mstj(109).NE.1)
THEN
73 sigu=2.*x1**2+x2**2*(1.+ct12**2)-qme*(3.+ct12**2-x1-x2)-
74 & qme*x1/xq+0.5*qme*((x2**2-qme)*st12**2-2.*x2)*xq
75 sigl=(x2*st12)**2-qme*(3.-ct12**2-2.5*(x1+x2)+x1*x2+qme)+
76 & 0.5*qme*(x1**2-x1-qme)/xq+0.5*qme*((x2**2-qme)*ct12**2-x2)*xq
77 sigt=0.5*(x2**2-qme-0.5*qme*(x2**2-qme)/xq)*st12**2
78 sigi=((1.-0.5*qme*xq)*(x2**2-qme)*st12*ct12+qme*(1.-x1-x2+
79 & 0.5*x1*x2+0.5*qme)*st12/ct12)/sq2
81 sigp=2.*(x1**2-x2**2*ct12)
85 sigu=2.*(2.-x1-x2)**2-(x2*st12)**2
88 sigi=-(2.-x1-x2)*x2*st12/sq2
99 sigmax=(2.*hf1a+hf3a+hf4a)*abs(sigu)+2.*(hf1a+hf3a+hf4a)*
100 &abs(sigl)+2.*(hf1a+2.*hf3a+2.*hf4a)*abs(sigt)+2.*sq2*
101 &(hf1a+2.*hf3a+2.*hf4a)*abs(sigi)+4.*sq2*hf2a*abs(siga)+
105 100 chi=paru(2)*
rlu(0)
114 c2phi=cos(2.*(
phi-parj(134)))
115 s2phi=sin(2.*(
phi-parj(134)))
116 sig=((1.+cthe**2)*hf1+sthe**2*(c2phi*hf3-s2phi*hf4))*sigu+
117 &2.*(sthe**2*hf1-sthe**2*(c2phi*hf3-s2phi*hf4))*sigl+
118 &2.*(sthe**2*c2chi*hf1+((1.+cthe**2)*c2chi*c2phi-2.*cthe*s2chi*
119 &s2phi)*hf3-((1.+cthe**2)*c2chi*s2phi+2.*cthe*s2chi*c2phi)*hf4)*
120 &sigt-2.*sq2*(2.*sthe*cthe*cchi*hf1-2.*sthe*(cthe*cchi*c2phi-
121 &schi*s2phi)*hf3+2.*sthe*(cthe*cchi*s2phi+schi*c2phi)*hf4)*sigi+
122 &4.*sq2*sthe*cchi*hf2*siga+2.*cthe*hf2*sigp
123 IF(sig.LT.sigmax*
rlu(0)) goto 100