2 C*********************************************************************
4 SUBROUTINE LUBOEI(NSAV)
6 C...Purpose: to modify event so as to approximately take into account
7 C...Bose-Einstein effects according to a simple phenomenological
9 IMPLICIT DOUBLE PRECISION(D)
10 COMMON/LUJETS/N,K(4000,5),P(4000,5),V(4000,5)
11 COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
12 SAVE /LUJETS/,/LUDAT1/
13 DIMENSION DPS(4),KFBE(9),NBE(0:9),BEI(100)
14 DATA KFBE/211,-211,111,321,-321,130,310,221,331/
16 C...Boost event to overall CM frame. Calculate CM energy.
17 IF((MSTJ(51).NE.1.AND.MSTJ(51).NE.2).OR.N-NSAV.LE.1) RETURN
23 IF(K(I,1).LE.10.AND.((KFA.GT.10.AND.KFA.LE.20).OR.KFA.EQ.22).AND.
25 KFMA=IABS(K(K(I,3),2))
26 IF(KFMA.GT.10.AND.KFMA.LE.80) K(I,1)=-K(I,1)
28 IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 120
33 CALL LUDBRB(0,0,0.,0.,-DPS(1)/DPS(4),-DPS(2)/DPS(4),
37 IF(K(I,1).GE.1.AND.K(I,1).LE.10) PECM=PECM+P(I,4)
40 C...Reserve copy of particles by species at end of record.
42 DO 160 IBE=1,MIN(9,MSTJ(52))
45 IF(K(I,2).NE.KFBE(IBE)) GOTO 150
46 IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 150
47 IF(NBE(IBE).GE.MSTU(4)-MSTU(32)-5) THEN
48 CALL LUERRM(11,'(LUBOEI:) no more memory left in LUJETS')
58 IF(NBE(MIN(9,MSTJ(52)))-NBE(0).LE.1) GOTO 280
60 C...Tabulate integral for subsequent momentum shift.
61 DO 220 IBE=1,MIN(9,MSTJ(52))
62 IF(IBE.NE.1.AND.IBE.NE.4.AND.IBE.LE.7) GOTO 180
63 IF(IBE.EQ.1.AND.MAX(NBE(1)-NBE(0),NBE(2)-NBE(1),NBE(3)-NBE(2))
65 IF(IBE.EQ.4.AND.MAX(NBE(4)-NBE(3),NBE(5)-NBE(4),NBE(6)-NBE(5),
66 &NBE(7)-NBE(6)).LE.1) GOTO 180
67 IF(IBE.GE.8.AND.NBE(IBE)-NBE(IBE-1).LE.1) GOTO 180
68 IF(IBE.EQ.1) PMHQ=2.*ULMASS(211)
69 IF(IBE.EQ.4) PMHQ=2.*ULMASS(321)
70 IF(IBE.EQ.8) PMHQ=2.*ULMASS(221)
71 IF(IBE.EQ.9) PMHQ=2.*ULMASS(331)
72 QDEL=0.1*MIN(PMHQ,PARJ(93))
73 IF(MSTJ(51).EQ.1) THEN
74 NBIN=MIN(100,NINT(9.*PARJ(93)/QDEL))
75 BEEX=EXP(0.5*QDEL/PARJ(93))
76 BERT=EXP(-QDEL/PARJ(93))
78 NBIN=MIN(100,NINT(3.*PARJ(93)/QDEL))
82 BEI(IBIN)=QDEL*(QBIN**2+QDEL**2/12.)/SQRT(QBIN**2+PMHQ**2)
83 IF(MSTJ(51).EQ.1) THEN
85 BEI(IBIN)=BEI(IBIN)*BEEX
87 BEI(IBIN)=BEI(IBIN)*EXP(-(QBIN/PARJ(93))**2)
89 IF(IBIN.GE.2) BEI(IBIN)=BEI(IBIN)+BEI(IBIN-1)
92 C...Loop through particle pairs and find old relative momentum.
93 180 DO 210 I1M=NBE(IBE-1)+1,NBE(IBE)-1
95 DO 200 I2M=I1M+1,NBE(IBE)
97 Q2OLD=MAX(0.,(P(I1,4)+P(I2,4))**2-(P(I1,1)+P(I2,1))**2-(P(I1,2)+
98 &P(I2,2))**2-(P(I1,3)+P(I2,3))**2-(P(I1,5)+P(I2,5))**2)
101 C...Calculate new relative momentum.
102 IF(QOLD.LT.1E-3*QDEL) THEN
104 ELSEIF(QOLD.LE.QDEL) THEN
106 ELSEIF(QOLD.LT.(NBIN-0.1)*QDEL) THEN
109 RINP=(RBIN**3-IBIN**3)/(3*IBIN*(IBIN+1)+1)
110 QMOV=(BEI(IBIN)+RINP*(BEI(IBIN+1)-BEI(IBIN)))*
111 & SQRT(Q2OLD+PMHQ**2)/Q2OLD
113 QMOV=BEI(NBIN)*SQRT(Q2OLD+PMHQ**2)/Q2OLD
115 Q2NEW=Q2OLD*(QOLD/(QOLD+3.*PARJ(92)*QMOV))**(2./3.)
117 C...Calculate and save shift to be performed on three-momenta.
118 HC1=(P(I1,4)+P(I2,4))**2-(Q2OLD-Q2NEW)
119 HC2=(Q2OLD-Q2NEW)*(P(I1,4)-P(I2,4))**2
120 HA=0.5*(1.-SQRT(HC1*Q2NEW/(HC1*Q2OLD-HC2)))
122 PD=HA*(P(I2,J)-P(I1,J))
130 C...Shift momenta and recalculate energies.
131 DO 240 IM=NBE(0)+1,NBE(MIN(9,MSTJ(52)))
134 P(I,J)=P(I,J)+P(IM,J)
136 P(I,4)=SQRT(P(I,5)**2+P(I,1)**2+P(I,2)**2+P(I,3)**2)
139 C...Rescale all momenta for energy conservation.
143 IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 250
145 PQS=PQS+P(I,5)**2/P(I,4)
147 FAC=(PECM-PQS)/(PES-PQS)
149 IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 270
153 P(I,4)=SQRT(P(I,5)**2+P(I,1)**2+P(I,2)**2+P(I,3)**2)
156 C...Boost back to correct reference frame.
157 280 CALL LUDBRB(0,0,0.,0.,DPS(1)/DPS(4),DPS(2)/DPS(4),DPS(3)/DPS(4))
159 IF(K(I,1).LT.0) K(I,1)=-K(I,1)