* \$Id\$ C********************************************************************* SUBROUTINE LURADK_HIJING(ECM,MK,PAK,THEK,PHIK,ALPK) C...Purpose: to generate initial state photon radiation. #include "ludat1_hijing.inc" C...Function: cumulative hard photon spectrum in QFD case. FXK(XX)=2.*LOG(XX)+PARJ(161)*LOG(1.-XX)+PARJ(162)*XX+ &PARJ(163)*LOG((XX-SZM)**2+SZW**2)+PARJ(164)*ATAN((XX-SZM)/SZW) C...Determine whether radiative photon or not. MK=0 PAK=0. IF(PARJ(160).LT.RLU_HIJING(0)) RETURN MK=1 C...Photon energy range. Find photon momentum in QED case. XKL=PARJ(135) XKU=MIN(PARJ(136),1.-(2.*PARJ(127)/ECM)**2) IF(MSTJ(102).LE.1) THEN 100 XK=1./(1.+(1./XKL-1.)*((1./XKU-1.)/(1./XKL-1.))**RLU_HIJING(0)) IF(1.+(1.-XK)**2.LT.2.*RLU_HIJING(0)) GOTO 100 C...Ditto in QFD case, by numerical inversion of integrated spectrum. ELSE SZM=1.-(PARJ(123)/ECM)**2 SZW=PARJ(123)*PARJ(124)/ECM**2 FXKL=FXK(XKL) FXKU=FXK(XKU) FXKD=1E-4*(FXKU-FXKL) FXKR=FXKL+RLU_HIJING(0)*(FXKU-FXKL) NXK=0 110 NXK=NXK+1 XK=0.5*(XKL+XKU) FXKV=FXK(XK) IF(FXKV.GT.FXKR) THEN XKU=XK FXKU=FXKV ELSE XKL=XK FXKL=FXKV ENDIF IF(NXK.LT.15.AND.FXKU-FXKL.GT.FXKD) GOTO 110 XK=XKL+(XKU-XKL)*(FXKR-FXKL)/(FXKU-FXKL) ENDIF PAK=0.5*ECM*XK C...Photon polar and azimuthal angle. PME=2.*(ULMASS_HIJING(11)/ECM)**2 120 CTHM=PME*(2./PME)**RLU_HIJING(0) IF(1.-(XK**2*CTHM*(1.-0.5*CTHM)+2.*(1.-XK)*PME/MAX(PME, &CTHM*(1.-0.5*CTHM)))/(1.+(1.-XK)**2).LT.RLU_HIJING(0)) GOTO 120 CTHE=1.-CTHM IF(RLU_HIJING(0).GT.0.5) CTHE=-CTHE STHE=SQRT(MAX(0.,(CTHM-PME)*(2.-CTHM))) THEK=ULANGL_HIJING(CTHE,STHE) PHIK=PARU(2)*RLU_HIJING(0) C...Rotation angle for hadronic system. SGN=1. IF(0.5*(2.-XK*(1.-CTHE))**2/((2.-XK)**2+(XK*CTHE)**2).GT. &RLU_HIJING(0)) SGN=-1. ALPK=ASIN(SGN*STHE*(XK-SGN*(2.*SQRT(1.-XK)-2.+XK)*CTHE)/ &(2.-XK*(1.-SGN*CTHE))) RETURN END