+++ /dev/null
-
-C*********************************************************************
-
- SUBROUTINE LUXTOT(KFL,ECM,XTOT)
-
-C...Purpose: to calculate total cross-section, including initial
-C...state radiation effects.
- COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
- COMMON/LUDAT2/KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4)
- SAVE /LUDAT1/,/LUDAT2/
-
-C...Status, (optimized) Q^2 scale, alpha_strong.
- PARJ(151)=ECM
- MSTJ(119)=10*MSTJ(102)+KFL
- IF(MSTJ(111).EQ.0) THEN
- Q2R=ECM**2
- ELSEIF(MSTU(111).EQ.0) THEN
- PARJ(168)=MIN(1.,MAX(PARJ(128),EXP(-12.*PARU(1)/
- & ((33.-2.*MSTU(112))*PARU(111)))))
- Q2R=PARJ(168)*ECM**2
- ELSE
- PARJ(168)=MIN(1.,MAX(PARJ(128),PARU(112)/ECM,
- & (2.*PARU(112)/ECM)**2))
- Q2R=PARJ(168)*ECM**2
- ENDIF
- ALSPI=ULALPS(Q2R)/PARU(1)
-
-C...QCD corrections factor in R.
- IF(MSTJ(101).EQ.0.OR.MSTJ(109).EQ.1) THEN
- RQCD=1.
- ELSEIF(IABS(MSTJ(101)).EQ.1.AND.MSTJ(109).EQ.0) THEN
- RQCD=1.+ALSPI
- ELSEIF(MSTJ(109).EQ.0) THEN
- RQCD=1.+ALSPI+(1.986-0.115*MSTU(118))*ALSPI**2
- IF(MSTJ(111).EQ.1) RQCD=MAX(1.,RQCD+(33.-2.*MSTU(112))/12.*
- & LOG(PARJ(168))*ALSPI**2)
- ELSEIF(IABS(MSTJ(101)).EQ.1) THEN
- RQCD=1.+(3./4.)*ALSPI
- ELSE
- RQCD=1.+(3./4.)*ALSPI-(3./32.+0.519*MSTU(118))*ALSPI**2
- ENDIF
-
-C...Calculate Z0 width if default value not acceptable.
- IF(MSTJ(102).GE.3) THEN
- RVA=3.*(3.+(4.*PARU(102)-1.)**2)+6.*RQCD*(2.+(1.-8.*PARU(102)/
- & 3.)**2+(4.*PARU(102)/3.-1.)**2)
- DO 100 KFLC=5,6
- VQ=1.
- IF(MOD(MSTJ(103),2).EQ.1) VQ=SQRT(MAX(0.,1.-(2.*ULMASS(KFLC)/
- & ECM)**2))
- IF(KFLC.EQ.5) VF=4.*PARU(102)/3.-1.
- IF(KFLC.EQ.6) VF=1.-8.*PARU(102)/3.
- RVA=RVA+3.*RQCD*(0.5*VQ*(3.-VQ**2)*VF**2+VQ**3)
- 100 CONTINUE
- PARJ(124)=PARU(101)*PARJ(123)*RVA/(48.*PARU(102)*(1.-PARU(102)))
- ENDIF
-
-C...Calculate propagator and related constants for QFD case.
- POLL=1.-PARJ(131)*PARJ(132)
- IF(MSTJ(102).GE.2) THEN
- SFF=1./(16.*PARU(102)*(1.-PARU(102)))
- SFW=ECM**4/((ECM**2-PARJ(123)**2)**2+(PARJ(123)*PARJ(124))**2)
- SFI=SFW*(1.-(PARJ(123)/ECM)**2)
- VE=4.*PARU(102)-1.
- SF1I=SFF*(VE*POLL+PARJ(132)-PARJ(131))
- SF1W=SFF**2*((VE**2+1.)*POLL+2.*VE*(PARJ(132)-PARJ(131)))
- HF1I=SFI*SF1I
- HF1W=SFW*SF1W
- ENDIF
-
-C...Loop over different flavours: charge, velocity.
- RTOT=0.
- RQQ=0.
- RQV=0.
- RVA=0.
- DO 110 KFLC=1,MAX(MSTJ(104),KFL)
- IF(KFL.GT.0.AND.KFLC.NE.KFL) GOTO 110
- MSTJ(93)=1
- PMQ=ULMASS(KFLC)
- IF(ECM.LT.2.*PMQ+PARJ(127)) GOTO 110
- QF=KCHG(KFLC,1)/3.
- VQ=1.
- IF(MOD(MSTJ(103),2).EQ.1) VQ=SQRT(1.-(2.*PMQ/ECM)**2)
-
-C...Calculate R and sum of charges for QED or QFD case.
- RQQ=RQQ+3.*QF**2*POLL
- IF(MSTJ(102).LE.1) THEN
- RTOT=RTOT+3.*0.5*VQ*(3.-VQ**2)*QF**2*POLL
- ELSE
- VF=SIGN(1.,QF)-4.*QF*PARU(102)
- RQV=RQV-6.*QF*VF*SF1I
- RVA=RVA+3.*(VF**2+1.)*SF1W
- RTOT=RTOT+3.*(0.5*VQ*(3.-VQ**2)*(QF**2*POLL-2.*QF*VF*HF1I+
- & VF**2*HF1W)+VQ**3*HF1W)
- ENDIF
- 110 CONTINUE
- RSUM=RQQ
- IF(MSTJ(102).GE.2) RSUM=RQQ+SFI*RQV+SFW*RVA
-
-C...Calculate cross-section, including QCD corrections.
- PARJ(141)=RQQ
- PARJ(142)=RTOT
- PARJ(143)=RTOT*RQCD
- PARJ(144)=PARJ(143)
- PARJ(145)=PARJ(141)*86.8/ECM**2
- PARJ(146)=PARJ(142)*86.8/ECM**2
- PARJ(147)=PARJ(143)*86.8/ECM**2
- PARJ(148)=PARJ(147)
- PARJ(157)=RSUM*RQCD
- PARJ(158)=0.
- PARJ(159)=0.
- XTOT=PARJ(147)
- IF(MSTJ(107).LE.0) RETURN
-
-C...Virtual cross-section.
- XKL=PARJ(135)
- XKU=MIN(PARJ(136),1.-(2.*PARJ(127)/ECM)**2)
- ALE=2.*LOG(ECM/ULMASS(11))-1.
- SIGV=ALE/3.+2.*LOG(ECM**2/(ULMASS(13)*ULMASS(15)))/3.-4./3.+
- &1.526*LOG(ECM**2/0.932)
-
-C...Soft and hard radiative cross-section in QED case.
- IF(MSTJ(102).LE.1) THEN
- SIGV=1.5*ALE-0.5+PARU(1)**2/3.+2.*SIGV
- SIGS=ALE*(2.*LOG(XKL)-LOG(1.-XKL)-XKL)
- SIGH=ALE*(2.*LOG(XKU/XKL)-LOG((1.-XKU)/(1.-XKL))-(XKU-XKL))
-
-C...Soft and hard radiative cross-section in QFD case.
- ELSE
- SZM=1.-(PARJ(123)/ECM)**2
- SZW=PARJ(123)*PARJ(124)/ECM**2
- PARJ(161)=-RQQ/RSUM
- PARJ(162)=-(RQQ+RQV+RVA)/RSUM
- PARJ(163)=(RQV*(1.-0.5*SZM-SFI)+RVA*(1.5-SZM-SFW))/RSUM
- PARJ(164)=(RQV*SZW**2*(1.-2.*SFW)+RVA*(2.*SFI+SZW**2-4.+3.*SZM-
- & SZM**2))/(SZW*RSUM)
- SIGV=1.5*ALE-0.5+PARU(1)**2/3.+((2.*RQQ+SFI*RQV)/RSUM)*SIGV+
- & (SZW*SFW*RQV/RSUM)*PARU(1)*20./9.
- SIGS=ALE*(2.*LOG(XKL)+PARJ(161)*LOG(1.-XKL)+PARJ(162)*XKL+
- & PARJ(163)*LOG(((XKL-SZM)**2+SZW**2)/(SZM**2+SZW**2))+
- & PARJ(164)*(ATAN((XKL-SZM)/SZW)-ATAN(-SZM/SZW)))
- SIGH=ALE*(2.*LOG(XKU/XKL)+PARJ(161)*LOG((1.-XKU)/(1.-XKL))+
- & PARJ(162)*(XKU-XKL)+PARJ(163)*LOG(((XKU-SZM)**2+SZW**2)/
- & ((XKL-SZM)**2+SZW**2))+PARJ(164)*(ATAN((XKU-SZM)/SZW)-
- & ATAN((XKL-SZM)/SZW)))
- ENDIF
-
-C...Total cross-section and fraction of hard photon events.
- PARJ(160)=SIGH/(PARU(1)/PARU(101)+SIGV+SIGS+SIGH)
- PARJ(157)=RSUM*(1.+(PARU(101)/PARU(1))*(SIGV+SIGS+SIGH))*RQCD
- PARJ(144)=PARJ(157)
- PARJ(148)=PARJ(144)*86.8/ECM**2
- XTOT=PARJ(148)
-
- RETURN
- END
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff