3 C*********************************************************************
5 FUNCTION ULMASS_HIJING(KF)
7 C...Purpose: to give the mass of a particle/parton.
8 #include "ludat1_hijing.inc"
9 #include "ludat2_hijing.inc"
11 C...Reset variables. Compressed code.
20 C...Guarantee use of constituent masses for internal checks.
21 IF((MSTJ(93).EQ.1.OR.MSTJ(93).EQ.2).AND.KFA.LE.10) THEN
22 ULMASS_HIJING=PARF(100+KFA)
23 IF(MSTJ(93).EQ.2) ULMASS_HIJING=MAX(0.,ULMASS_HIJING-PARF(121))
25 C...Masses that can be read directly off table.
26 ELSEIF(KFA.LE.100.OR.KC.LE.80.OR.KC.GT.100) THEN
27 ULMASS_HIJING=PMAS(KC,1)
29 C...Find constituent partons and their masses.
35 KFLR=MOD(KFA/10000,10)
40 C...Construct masses for various meson, diquark and baryon cases.
41 IF(KFLA.EQ.0.AND.KFLR.EQ.0.AND.KFLS.LE.3) THEN
42 IF(KFLS.EQ.1) PMSPL=-3./(PMB*PMC)
43 IF(KFLS.GE.3) PMSPL=1./(PMB*PMC)
44 ULMASS_HIJING=PARF(111)+PMB+PMC+PARF(113)*PARF(101)**2*PMSPL
45 ELSEIF(KFLA.EQ.0) THEN
50 ULMASS_HIJING=PARF(113+KMUL)+PMB+PMC
51 ELSEIF(KFLC.EQ.0) THEN
52 IF(KFLS.EQ.1) PMSPL=-3./(PMA*PMB)
53 IF(KFLS.EQ.3) PMSPL=1./(PMA*PMB)
54 ULMASS_HIJING=2.*PARF(112)/3.+PMA+PMB+PARF(114)*PARF(101)**2
56 IF(MSTJ(93).EQ.1) ULMASS_HIJING=PMA+PMB
57 IF(MSTJ(93).EQ.2) ULMASS_HIJING=MAX(0.,ULMASS_HIJING-PARF(122)
60 IF(KFLS.EQ.2.AND.KFLA.EQ.KFLB) THEN
61 PMSPL=1./(PMA*PMB)-2./(PMA*PMC)-2./(PMB*PMC)
62 ELSEIF(KFLS.EQ.2.AND.KFLB.GE.KFLC) THEN
63 PMSPL=-2./(PMA*PMB)-2./(PMA*PMC)+1./(PMB*PMC)
64 ELSEIF(KFLS.EQ.2) THEN
67 PMSPL=1./(PMA*PMB)+1./(PMA*PMC)+1./(PMB*PMC)
69 ULMASS_HIJING=PARF(112)+PMA+PMB+PMC+PARF(114)*PARF(101)**2
74 C...Optional mass broadening according to truncated Breit-Wigner
75 C...(either in m or in m^2).
76 IF(MSTJ(24).GE.1.AND.PMAS(KC,2).GT.1E-4) THEN
77 IF(MSTJ(24).EQ.1.OR.(MSTJ(24).EQ.2.AND.KFA.GT.100)) THEN
78 ULMASS_HIJING=ULMASS_HIJING+0.5*PMAS(KC,2)*TAN((2.
79 $ *RLU_HIJING(0)-1.)*ATAN(2.*PMAS(KC,3)/PMAS(KC,2)))
82 PMLOW=ATAN((MAX(0.,PM0-PMAS(KC,3))**2-PM0**2)/
84 PMUPP=ATAN((PM0+PMAS(KC,3))**2-PM0**2)/(PM0*PMAS(KC,2))
85 ULMASS_HIJING=SQRT(MAX(0.,PM0**2+PM0*PMAS(KC,2)*TAN(PMLOW+
86 & (PMUPP-PMLOW)*RLU_HIJING(0))))