3 C*********************************************************************
5 SUBROUTINE LUCELL_HIJING(NJET)
7 C...Purpose: to provide a simple way of jet finding in an eta-phi-ET
8 C...coordinate frame, as used for calorimeters at hadron colliders.
9 #include "lujets_hijing.inc"
10 #include "ludat1_hijing.inc"
11 #include "ludat2_hijing.inc"
13 C...Loop over all particles. Find cell that was hit by given particle.
14 NCE2=2*MSTU(51)*MSTU(52)
15 PTLRAT=1./SINH(PARU(51))**2
19 IF(K(I,1).LE.0.OR.K(I,1).GT.10) GOTO 110
20 IF(P(I,1)**2+P(I,2)**2.LE.PTLRAT*P(I,3)**2) GOTO 110
21 IF(MSTU(41).GE.2) THEN
22 KC=LUCOMP_HIJING(K(I,2))
23 IF(KC.EQ.0.OR.KC.EQ.12.OR.KC.EQ.14.OR.KC.EQ.16.OR.
25 IF(MSTU(41).GE.3.AND.KCHG(KC,2).EQ.0.AND.LUCHGE_HIJING(K(I,2))
29 PT=SQRT(P(I,1)**2+P(I,2)**2)
30 ETA=SIGN(LOG((SQRT(PT**2+P(I,3)**2)+ABS(P(I,3)))/PT),P(I,3))
31 IETA=MAX(1,MIN(MSTU(51),1+INT(MSTU(51)*0.5*(ETA/PARU(51)+1.))))
32 PHI=ULANGL_HIJING(P(I,1),P(I,2))
33 IPHI=MAX(1,MIN(MSTU(52),1+INT(MSTU(52)*0.5*(PHI/PARU(1)+1.))))
34 IETPH=MSTU(52)*IETA+IPHI
36 C...Add to cell already hit, or book new cell.
38 IF(IETPH.EQ.K(IC,3)) THEN
44 IF(NC.GE.MSTU(4)-MSTU(32)-5) THEN
46 $ ,'(LUCELL_HIJING:) no more memory left in LUJETS_HIJING')
54 P(NC,1)=(PARU(51)/MSTU(51))*(2*IETA-1-MSTU(51))
55 P(NC,2)=(PARU(1)/MSTU(52))*(2*IPHI-1-MSTU(52))
59 C...Smear true bin content by calorimeter resolution.
60 IF(MSTU(53).GE.1) THEN
63 IF(MSTU(53).EQ.2) PEI=P(IC,5)/COSH(P(IC,1))
64 120 PEF=PEI+PARU(55)*SQRT(-2.*LOG(MAX(1E-10,RLU_HIJING(0)))*PEI)*
65 & COS(PARU(2)*RLU_HIJING(0))
66 IF(PEF.LT.0..OR.PEF.GT.PARU(56)*PEI) GOTO 120
68 130 IF(MSTU(53).EQ.2) P(IC,5)=PEF*COSH(P(IC,1))
71 C...Find initiator cell: the one with highest pT of not yet used ones.
75 IF(K(IC,5).NE.2) GOTO 150
76 IF(P(IC,5).LE.ETMAX) GOTO 150
82 IF(ETMAX.LT.PARU(52)) GOTO 210
83 IF(NJ.GE.MSTU(4)-MSTU(32)-5) THEN
85 $ ,'(LUCELL_HIJING:) no more memory left in LUJETS_HIJING')
99 C...Sum up unused cells within required distance of initiator.
101 IF(K(IC,5).EQ.0) GOTO 160
102 IF(ABS(P(IC,1)-ETA).GT.PARU(54)) GOTO 160
103 DPHIA=ABS(P(IC,2)-PHI)
104 IF(DPHIA.GT.PARU(54).AND.DPHIA.LT.PARU(2)-PARU(54)) GOTO 160
106 IF(DPHIA.GT.PARU(1)) PHIC=PHIC+SIGN(PARU(2),PHI)
107 IF((P(IC,1)-ETA)**2+(PHIC-PHI)**2.GT.PARU(54)**2) GOTO 160
109 K(NJ,4)=K(NJ,4)+K(IC,4)
110 P(NJ,3)=P(NJ,3)+P(IC,5)*P(IC,1)
111 P(NJ,4)=P(NJ,4)+P(IC,5)*PHIC
112 P(NJ,5)=P(NJ,5)+P(IC,5)
115 C...Reject cluster below minimum ET, else accept.
116 IF(P(NJ,5).LT.PARU(53)) THEN
119 170 IF(K(IC,5).LT.0) K(IC,5)=-K(IC,5)
120 ELSEIF(MSTU(54).LE.2) THEN
121 P(NJ,3)=P(NJ,3)/P(NJ,5)
122 P(NJ,4)=P(NJ,4)/P(NJ,5)
123 IF(ABS(P(NJ,4)).GT.PARU(1)) P(NJ,4)=P(NJ,4)-SIGN(PARU(2),
126 180 IF(K(IC,1).LT.0) K(IC,1)=0
131 IF(K(IC,5).GE.0) GOTO 200
132 P(NJ,1)=P(NJ,1)+P(IC,5)*COS(P(IC,2))
133 P(NJ,2)=P(NJ,2)+P(IC,5)*SIN(P(IC,2))
134 P(NJ,3)=P(NJ,3)+P(IC,5)*SINH(P(IC,1))
135 P(NJ,4)=P(NJ,4)+P(IC,5)*COSH(P(IC,1))
141 C...Arrange clusters in falling ET sequence.
145 IF(K(IJ,5).EQ.0) GOTO 220
146 IF(P(IJ,5).LT.ETMAX) GOTO 220
161 C...Convert to massless or massive four-vectors.
162 IF(MSTU(54).EQ.2) THEN
165 P(I,1)=P(I,5)*COS(P(I,4))
166 P(I,2)=P(I,5)*SIN(P(I,4))
167 P(I,3)=P(I,5)*SINH(ETA)
168 P(I,4)=P(I,5)*COSH(ETA)
170 ELSEIF(MSTU(54).GE.3) THEN
172 250 P(I,5)=SQRT(MAX(0.,P(I,4)**2-P(I,1)**2-P(I,2)**2-P(I,3)**2))
175 C...Information about storage.
179 IF(MSTU(43).LE.1) MSTU(3)=NJET
180 IF(MSTU(43).GE.2) N=N+NJET