3 C*********************************************************************
5 SUBROUTINE LUEEVT_HIJING(KFL,ECM)
7 C...Purpose: to handle the generation of an e+e- annihilation jet event.
8 IMPLICIT DOUBLE PRECISION(D)
9 #include "lujets_hijing.inc"
10 #include "ludat1_hijing.inc"
11 #include "ludat2_hijing.inc"
13 C...Check input parameters.
14 IF(MSTU(12).GE.1) CALL LULIST_HIJING(0)
15 IF(KFL.LT.0.OR.KFL.GT.8) THEN
17 $ ,'(LUEEVT_HIJING:) called with unknown flavour code')
18 IF(MSTU(21).GE.1) RETURN
20 IF(KFL.LE.5) ECMMIN=PARJ(127)+2.02*PARF(100+MAX(1,KFL))
21 IF(KFL.GE.6) ECMMIN=PARJ(127)+2.02*PMAS(KFL,1)
22 IF(ECM.LT.ECMMIN) THEN
24 $ ,'(LUEEVT_HIJING:) called with too small CM energy')
25 IF(MSTU(21).GE.1) RETURN
28 C...Check consistency of MSTJ options set.
29 IF(MSTJ(109).EQ.2.AND.MSTJ(110).NE.1) THEN
31 & '(LUEEVT_HIJING:) MSTJ(109) value requires MSTJ(110) = 1')
34 IF(MSTJ(109).EQ.2.AND.MSTJ(111).NE.0) THEN
36 & '(LUEEVT_HIJING:) MSTJ(109) value requires MSTJ(111) = 0')
40 C...Initialize alpha_strong and total cross-section.
42 IF(MSTJ(108).EQ.2.AND.(MSTJ(101).EQ.0.OR.MSTJ(101).EQ.1))
45 IF(MSTU(111).EQ.2) PARU(112)=PARJ(122)
46 IF(MSTJ(116).GT.0.AND.(MSTJ(116).GE.2.OR.ABS(ECM-PARJ(151)).GE.
47 & PARJ(139).OR.10*MSTJ(102)+KFL.NE.MSTJ(119))) CALL
48 $ LUXTOT_HIJING(KFL,ECM,XTOT)
49 IF(MSTJ(116).GE.3) MSTJ(116)=1
51 C...Add initial e+e- to event record (documentation only).
56 $ ,'(LUEEVT_HIJING:) caught in an infinite loop')
60 IF(MSTJ(115).GE.2) THEN
62 CALL LU1ENT_HIJING(NC-1,11,0.5*ECM,0.,0.)
64 CALL LU1ENT_HIJING(NC,-11,0.5*ECM,PARU(1),0.)
68 C...Radiative photon (in initial state).
71 IF(MSTJ(107).GE.1.AND.MSTJ(116).GE.1) CALL LURADK_HIJING(ECM,MK
72 $ ,PAK,THEK,PHIK,ALPK)
73 IF(MK.EQ.1) ECMC=SQRT(ECM*(ECM-2.*PAK))
74 IF(MSTJ(115).GE.1.AND.MK.EQ.1) THEN
76 CALL LU1ENT_HIJING(NC,22,PAK,THEK,PHIK)
77 K(NC,3)=MIN(MSTJ(115)/2,1)
80 C...Virtual exchange boson (gamma or Z0).
81 IF(MSTJ(115).GE.3) THEN
84 IF(MSTJ(102).EQ.2) KF=23
88 CALL LU1ENT_HIJING(NC,KF,ECMC,0.,0.)
94 C...Choice of flavour and jet configuration.
95 CALL LUXKFL_HIJING(KFL,ECM,ECMC,KFLC)
96 IF(KFLC.EQ.0) GOTO 100
97 CALL LUXJET_HIJING(ECMC,NJET,CUT)
99 IF(NJET.EQ.4) CALL LUX4JT_HIJING(NJET,CUT,KFLC,ECMC,KFLN,X1,X2,X4,
101 IF(NJET.EQ.3) CALL LUX3JT_HIJING(NJET,CUT,KFLC,ECMC,X1,X3)
102 IF(NJET.EQ.2) MSTJ(120)=1
104 C...Fill jet configuration and origin.
105 IF(NJET.EQ.2.AND.MSTJ(101).NE.5) CALL LU2ENT_HIJING(NC+1,KFLC,
107 IF(NJET.EQ.2.AND.MSTJ(101).EQ.5) CALL LU2ENT_HIJING(-(NC+1),KFLC,
109 IF(NJET.EQ.3) CALL LU3ENT_HIJING(NC+1,KFLC,21,-KFLC,ECMC,X1,X3)
110 IF(NJET.EQ.4.AND.KFLN.EQ.21) CALL LU4ENT_HIJING(NC+1,KFLC,KFLN
111 $ ,KFLN,-KFLC,ECMC,X1,X2,X4,X12,X14)
112 IF(NJET.EQ.4.AND.KFLN.NE.21) CALL LU4ENT_HIJING(NC+1,KFLC,-KFLN
113 $ ,KFLN,-KFLC,ECMC,X1,X2,X4,X12,X14)
115 110 K(IP,3)=K(IP,3)+MIN(MSTJ(115)/2,1)+(MSTJ(115)/3)*(NC-1)
117 C...Angular orientation according to matrix element.
118 IF(MSTJ(106).EQ.1) THEN
119 CALL LUXDIF_HIJING(NC,NJET,KFLC,ECMC,CHI,THE,PHI)
120 CALL LUDBRB_HIJING(NC+1,N,0.,CHI,0D0,0D0,0D0)
121 CALL LUDBRB_HIJING(NC+1,N,THE,PHI,0D0,0D0,0D0)
124 C...Rotation and boost from radiative photon.
127 NMIN=NC+1-MSTJ(115)/3
128 CALL LUDBRB_HIJING(NMIN,N,0.,-PHIK,0D0,0D0,0D0)
129 CALL LUDBRB_HIJING(NMIN,N,ALPK,0.,DBEK*SIN(THEK),0D0,DBEK
131 CALL LUDBRB_HIJING(NMIN,N,0.,PHIK,0D0,0D0,0D0)
134 C...Generate parton shower. Rearrange along strings and check.
135 IF(MSTJ(101).EQ.5) THEN
136 CALL LUSHOW_HIJING(N-1,N,ECMC)
138 IF(MSTJ(105).EQ.-1) MSTJ(14)=0
139 IF(MSTJ(105).GE.0) MSTU(28)=0
140 CALL LUPREP_HIJING(0)
142 IF(MSTJ(105).GE.0.AND.MSTU(28).NE.0) GOTO 100
145 C...Fragmentation/decay generation. Information for LUTABU_HIJING.
146 IF(MSTJ(105).EQ.1) CALL LUEXEC_HIJING