hijing/src/plu.f

0001
0002 C*********************************************************************
0003
0004       FUNCTION PLU(I,J)
0005
0006 C...Purpose: to provide various real-valued event related data.
0007       COMMON/LUJETS/N,K(9000,5),P(9000,5),V(9000,5)
0008       SAVE /LUJETS/
0009       COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
0010       SAVE /LUDAT1/
0011       COMMON/LUDAT2/KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4)
0012       SAVE /LUDAT2/
0013       DIMENSION PSUM(4)
0014
0015 C...Set default value. For I = 0 sum of momenta or charges,
0016 C...or invariant mass of system.
0017       PLU=0.
0018       IF(I.LT.0.OR.I.GT.MSTU(4).OR.J.LE.0) THEN
0019       ELSEIF(I.EQ.0.AND.J.LE.4) THEN
0020         DO 100 I1=1,N
0021   100   IF(K(I1,1).GT.0.AND.K(I1,1).LE.10) PLU=PLU+P(I1,J)
0022       ELSEIF(I.EQ.0.AND.J.EQ.5) THEN
0023         DO 110 J1=1,4
0024         PSUM(J1)=0.
0025         DO 110 I1=1,N
0026   110   IF(K(I1,1).GT.0.AND.K(I1,1).LE.10) PSUM(J1)=PSUM(J1)+P(I1,J1)
0027         PLU=SQRT(MAX(0.,PSUM(4)**2-PSUM(1)**2-PSUM(2)**2-PSUM(3)**2))
0028       ELSEIF(I.EQ.0.AND.J.EQ.6) THEN
0029         DO 120 I1=1,N
0030   120   IF(K(I1,1).GT.0.AND.K(I1,1).LE.10) PLU=PLU+LUCHGE(K(I1,2))/3.
0031       ELSEIF(I.EQ.0) THEN
0032
0033 C...Direct readout of P matrix.
0034       ELSEIF(J.LE.5) THEN
0035         PLU=P(I,J)
0036
0037 C...Charge, total momentum, transverse momentum, transverse mass.
0038       ELSEIF(J.LE.12) THEN
0039         IF(J.EQ.6) PLU=LUCHGE(K(I,2))/3.
0040         IF(J.EQ.7.OR.J.EQ.8) PLU=P(I,1)**2+P(I,2)**2+P(I,3)**2
0041         IF(J.EQ.9.OR.J.EQ.10) PLU=P(I,1)**2+P(I,2)**2
0042         IF(J.EQ.11.OR.J.EQ.12) PLU=P(I,5)**2+P(I,1)**2+P(I,2)**2
0043         IF(J.EQ.8.OR.J.EQ.10.OR.J.EQ.12) PLU=SQRT(PLU)
0044
0045 C...Theta and phi angle in radians or degrees.
0046       ELSEIF(J.LE.16) THEN
0047         IF(J.LE.14) PLU=ULANGL(P(I,3),SQRT(P(I,1)**2+P(I,2)**2))
0048         IF(J.GE.15) PLU=ULANGL(P(I,1),P(I,2))
0049         IF(J.EQ.14.OR.J.EQ.16) PLU=PLU*180./PARU(1)
0050
0051 C...True rapidity, rapidity with pion mass, pseudorapidity.
0052       ELSEIF(J.LE.19) THEN
0053         PMR=0.
0054         IF(J.EQ.17) PMR=P(I,5)
0055         IF(J.EQ.18) PMR=ULMASS(211)
0056         PR=MAX(1E-20,PMR**2+P(I,1)**2+P(I,2)**2)
0057         PLU=SIGN(LOG(MIN((SQRT(PR+P(I,3)**2)+ABS(P(I,3)))/SQRT(PR),
0058      &  1E20)),P(I,3))
0059
0060 C...Energy and momentum fractions (only to be used in CM frame).
0061       ELSEIF(J.LE.25) THEN
0062         IF(J.EQ.20) PLU=2.*SQRT(P(I,1)**2+P(I,2)**2+P(I,3)**2)/PARU(21)
0063         IF(J.EQ.21) PLU=2.*P(I,3)/PARU(21)
0064         IF(J.EQ.22) PLU=2.*SQRT(P(I,1)**2+P(I,2)**2)/PARU(21)
0065         IF(J.EQ.23) PLU=2.*P(I,4)/PARU(21)
0066         IF(J.EQ.24) PLU=(P(I,4)+P(I,3))/PARU(21)
0067         IF(J.EQ.25) PLU=(P(I,4)-P(I,3))/PARU(21)
0068       ENDIF
0069
0070       RETURN
0071       END