3 cgsfs added following line to match C++ call
4 double precision xmp, xmu, alpha, rscut2, cutof2
5 double precision smearp,smearh,dpcoal,drcoal,ecritl
7 COMMON/HMAIN1/EATT,JATT,NATT,NT,NP,N0,N01,N10,N11
8 COMMON /HPARNT/HIPR1(100), IHPR2(50), HINT1(100), IHNT2(50)
9 COMMON/LUDAT1A/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
10 COMMON /ARPRNT/ ARPAR1(100), IAPAR2(50), ARINT1(100), IAINT2(50)
12 COMMON /AREVT/ IAEVT, IARUN, MISS
13 COMMON /smearz/smearp,smearh
15 common/anim/nevent,isoft,isflag,izpc
16 c parton coalescence radii in case of string melting:
17 common /coal/dpcoal,drcoal,ecritl
18 common/snn/efrm,npart1,npart2
19 c initialization value for parton cascade:
20 common /para2/ xmp, xmu, alpha, rscut2, cutof2
21 common /para7/ ioscar,nsmbbbar,nsmmeson
22 common /para8/ idpert,npertd,idxsec
24 c initialization value for hadron cascade:
26 common/input1/ MASSPR,MASSTA,ISEED,IAVOID,DT
27 COMMON /INPUT2/ ILAB, MANYB, NTMAX, ICOLL, INSYS, IPOT, MODE,
28 & IMOMEN, NFREQ, ICFLOW, ICRHO, ICOU, KPOTEN, KMUL
29 common/oscar1/iap,izp,iat,izt
30 common/oscar2/FRAME,amptvn
31 common/resdcy/NSAV,iksdcy
33 c common/phidcy/iphidcy
34 common/phidcy/iphidcy,pttrig,ntrig,maxmiss
35 common/embed/iembed,pxqembd,pyqembd,xembd,yembd
38 EXTERNAL HIDATA, PYDATA, LUDATA, ARDATA, PPBDAT, zpcbdt
42 c flag to select default AMPT or string melting:
43 isoft = 1 ! ISOFT (D=1): select Default AMPT or String Melting(see below)
44 c read initialization value for hadron cascade:
45 NTMAX = 150 ! NTMAX: number of timesteps (D=150), see below
46 DT = 0.2 ! DT: timestep in fm (hadron cascade time= DT*NTMAX) (D=0.2)
47 c parj(41) and (42) are a and b parameters in Lund string fragmentation:
48 PARJ(41) = 0.5 ! PARJ(41): parameter a in Lund symmetric splitting function
49 PARJ(42) = 0.9 ! PARJ(42): parameter b in Lund symmetric splitting function
50 c IHPR2(11)=3 (or 2) allows the popcorn mechanism in PYTHIA and
51 c increase the net-baryon stopping in rapidity (value HIJING is 1):
52 ipop = 1 ! (D=1,yes;0,no) flag for popcorn mechanism(netbaryon stopping)
53 c PARJ(5) controls the fraction of BMBbar vs BBbar in popcorn:
54 PARJ(5) = 1.0 ! PARJ(5) to control BMBbar vs BBbar in popcorn (D=1.0)
55 c shadowing flag in HIJING:
56 IHPR2(6) = 1 ! shadowing flag (Default=1,yes; 0,no)
57 c quenching flag in HIJING:
58 IHPR2(4) = 0 ! quenching flag (D=0,no; 1,yes)
59 c quenching rate when quenching flag is on (=1.0 GeV/fm):
60 HIPR1(14) = 2.0 ! quenching parameter -dE/dx (GeV/fm) in case quenching flag=1
61 c Minimum pt of hard or semihard scatterings in HIJING: D=2.0 GeV.
62 HIPR1(8) = 2.0 ! p0 cutoff in HIJING for minijet productions (D=2.0)
63 c read initialization value for parton cascade:
64 xmu = 3.2264d0 ! parton screening mass in fm^(-1) (D=3.2264d0), see below
65 izpc = 0 ! IZPC: (D=0 forward-angle parton scatterings; 100,isotropic)
66 alpha = 0.3333d0 ! alpha in parton cascade
67 c quark coalescence radii in momentum and space for string melting:
68 dpcoal = 1d6 ! dpcoal in GeV
69 drcoal = 1d6 ! drcoal in fm
70 c flag: read in HIJING random # seed at runtime(1) or from input.ampt(D=0):
71 ihjsed = 0 ! ihjsed: take HIJING seed from below (D=0)or at runtime(11)
72 c 2 seeds for random number generators in HIJING/hadron cascade and ZPC:
73 nseed = 53153511 ! random seed for HIJING
74 iseedp = 8 ! random seed for parton cascade
75 iksdcy = 0 ! flag for Ks0 weak decays (D=0,no; 1,yes)
76 iphidcy = 1 ! flag for phi decays at end of hadron cascade (D=1,yes; 0,no)
77 c flag for OSCAR output for final partons and hadrons:
78 ioscar = 0 ! optional OSCAR output (D=0,no; 1,yes; 2&3,more parton info)
79 clin-5/2008 flag for perturbative treatment of deuterons:
80 idpert = 0 ! flag for perturbative deuteron calculation (D=0,no; 1or2,yes)
81 npertd = 1 ! integer factor for perturbative deuterons(>=1 & <=10000)
82 idxsec = 1 ! choice of cross section assumptions for deuteron reactions
83 clin-6/2009 To select events that have at least 1 high-Pt minijet parton:
84 pttrig = -7. ! Pt in GeV: generate events with >=1 minijet above this value
85 maxmiss = 1000 ! maxmiss (D=1000): maximum # of tries to repeat a HIJING event
86 IHPR2(2) = 3 ! flag to turn off initial and final state radiation (D=3)
87 IHPR2(5) = 1 ! flag to turn off Kt kick (D=1)
88 clin-6/2009 To embed a back-to-back q/qbar pair into each event:
89 iembed = 0 ! flag to turn on quark pair embedding (D=0,no; 1to4:yes)
90 pxqembd = 7. ! Initial Px and Py values (GeV) of the embedded quark (u or d)
92 xembd = 0. ! Initial x & y values (fm) of the embedded back-to-back q/qbar
94 nsembd = 1 ! nsembd(D=0), psembd (in GeV),tmaxembd (in radian).
97 clin-7/2009 Allow modification of nuclear shadowing:
98 ishadow = 0 ! Flag to enable users to modify shadowing (D=0,no; 1,yes)
99 dshadow = 1.d0 ! Factor used to modify nuclear shadowing
104 c$$$%%%%%%%%%% Further explanations:
105 c$$$ISOFT: 1 Default,
106 c$$$ 4 String Melting.
107 c$$$PARJ(41) & (42): 2.2 & 0.5/GeV^2 used for heavy ion (Au+Au, Pb+Pb) collisions,
108 c$$$ while the HIJING values (0.5 & 0.9/GeV^2) describe well
109 c$$$ Nch in pp collisions and are used for d-Au collisions.
110 c$$$NTMAX: number of time-steps for hadron cascade.
111 c$$$ Use a large value (e.g. 1000) for HBT studies in heavy ion collisions.
112 c$$$ Using NTMAX=3 effectively turns off hadronic cascade.
113 c$$$parton screening mass (in 1/fm): its square is inversely proportional to
114 c$$$ the parton cross section. Use D=3.2264d0 for 3mb cross section,
115 c$$$ and 2.2814d0 for 6mb. Using 1d4 effectively turns off parton cascade.
116 c$$$ihjsed: if =11, take HIJING random seed at runtime so that
117 c$$$ every run may be automatically different (see file 'exec').
118 c$$$iksdcy: flag for Ks0 weak decays for comparison with data.
119 c$$$iphidcy: flag for phi meson decays at the end of hadron cascade for comparison
120 c$$$ with data; default is yes; use 0 to turn off these decays.
121 c$$$ Note: phi meson decay during hadron cascade is always enabled.
122 c$$$ioscar: 0 Dafault,
123 c$$$ 1 Write output in the OSCAR format,
124 c$$$ 2 Write out the complete parton information
125 c$$$ (ana/parton-initial-afterPropagation.dat)
126 c$$$ right after string melting (before parton cascade),
127 c$$$ 3 Write out several more files on parton information (see readme).
128 c$$$idpert: flag for perturbative deuteron and antideuteron calculations
129 c$$$ with results in ana/ampt_pert.dat:
130 c$$$ 0 No perturbative calculations,
131 c$$$ 1 Trigger a production of NPERTD perturbative deuterons
132 c$$$ in each NN collision,
133 c$$$ 2 Trigger a production of NPERTD perturbative deuterons only in
134 c$$$ an NN collision where a conventional deuteron is produced.
135 c$$$ Note: conventional deuteron calculations are always performed
136 c$$$ with results in ana/ampt.dat.
137 c$$$NPERTD: number of perturbative deuterons produced in each triggered collision;
138 c$$$ setting it to 0 turns off perturbative deuteron productions.
139 c$$$idxsec: choose a cross section model for deuteron inelastic/elastic collisions:
140 c$$$ 1: same |matrix element|**2/s (after averaging over initial spins
141 c$$$ and isospins) for B+B -> deuteron+meson at the same sqrt(s);
142 c$$$ 2: same |matrix element|**2/s for B+B -> deuteron+meson
143 c$$$ at the same sqrt(s)-threshold;
144 c$$$ 3: same |matrix element|**2/s for deuteron+meson -> B+B
145 c$$$ at the same sqrt(s);
146 c$$$ 4: same |matrix element|**2/s for deuteron+meson -> B+B
147 c$$$ at the same sqrt(s)-threshold;
148 c$$$ 1 or 3 also chooses the same cross section for deuteron+meson or baryon
149 c$$$ elastic collision at the same sqrt(s);
150 c$$$ 2 or 4 also chooses the same cross section for deuteron+meson or baryon
151 c$$$ elastic collision at the same sqrt(s)-threshold.
152 c$$$%%%%%%%%%% For jet studies:
153 c$$$pttrig: generate events with at least 1 initial minijet parton above this Pt
154 c$$$ value, otherwise repeat HIJING event until reaching maxmiss tries;
155 c$$$ use a negative value to disable this requirement and get normal events.
156 c$$$maxmiss: maximum number of tries for the repetition of a HIJING event to obtain
157 c$$$ a minijet above the Pt value of pttrig; increase maxmiss if some events
158 c$$$ fail to generate at least 1 initial minijet parton above pttrig.
159 c$$$ it is safer to set a large value for high pttrig and/or large b value
160 c$$$ and/or smaller colliding nuclei.
161 c$$$IHPR2(2): flag to turn off initial and final state radiation:
162 c$$$ 0 both radiation off, 1 only final off, 2 only initial off, 3 both on.
163 c$$$IHPR2(5): flag to turn off Pt kick due to soft interactions: 0 off, 1 on.
164 c$$$ Setting both IHPR2(2) and IHPR2(5) to zero makes it more likely to
165 c$$$ have two high-Pt minijet partons that are close to back-to-back.
166 c$$$%%%%%%%%%% To embed a back-to-back light q/qbar jet pair
167 c$$$%%%%%%%%%% and a given number of soft pions along each jet into each event:
168 c$$$iembed: flag to turn on quark pair embedding:
169 c$$$ 1: on with fixed position(xembd,pembd) and Pt(pxqembd,pyqembd);
170 c$$$ 2: on with fixed position(xembd,pembd) and random azimuthal angle
171 c$$$ with Pt-magnitude given by sqrt(pxqembd^2+pyqembd^2);
172 c$$$ 3: on with random position and fixed Pt(pxqembd,pyqembd);
173 c$$$ 4: on with random position and random random azimuthal angle
174 c$$$ with Pt-magnitude given by sqrt(pxqembd^2+pyqembd^2);
175 c$$$ for iembed=3 or 4: need a position file "embed-jet-xy.txt";
176 c$$$ Other integers: off.
177 c$$$pxqembd, pyqembd: sqrt(pxqembd^2+pyqembd^2) > 70MeV/c is required;
178 c$$$ the embedded quark and antiquark have pz=0.
179 c$$$xembd, yembd: the embedded quark and antiquark jets have z=0 initially. Note:
180 c$$$ the x-axis is defined as the direction along the impact parameter.
181 c$$$nsembd: number of soft pions to be embedded with each high-Pt parton
182 c$$$ in the embedded jet pair.
183 c$$$psembd: Momentum of each embedded soft pion in GeV.
184 c$$$tmaxembd: maximum angle(rad) of embedded soft pions relative to high-Pt parton.
185 c$$$%%%%%%%%%% User modification of nuclear shadowing:
186 c$$$ishadow: set to 1 to enable users to adjust nuclear shadowing
187 c$$$ provided the shadowing flag IHPR2(6) is turned on; default value is 0.
188 c$$$dshadow: valid when ishadow=1; this parameter modifies the HIJING shadowing
189 c$$$ parameterization Ra(x,r)==1+fa(x,r) via Ra(x,r)==1+fa(x,r)*dshadow,
190 c$$$ so the value of 0.d0 turns off shadowing
191 c$$$ and the value of 1.d0 uses the default HIJING shadowing;
192 c$$$ currently limited to 0.d0<=dshadow<=1.d0 to make sure Ra(x,r)>0.