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4c039060 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* | |
17 | $Log$ | |
65fb704d | 18 | Revision 1.11 2000/10/20 06:30:06 fca |
19 | Use version 0 to avoid streamer generation | |
20 | ||
3be3dfc7 | 21 | Revision 1.10 2000/10/06 14:18:44 morsch |
22 | Upper cut of prim. pT distribution set to 5. GeV | |
23 | ||
e8d05e6c | 24 | Revision 1.9 2000/09/18 10:41:35 morsch |
25 | Add possibility to use nuclear structure functions from PDF library V8. | |
26 | ||
811826d8 | 27 | Revision 1.8 2000/09/06 14:26:24 morsch |
28 | Decayer functionality of AliPythia has been moved to AliDecayerPythia. | |
29 | Class is now a singleton. | |
30 | ||
95b811fe | 31 | Revision 1.7 2000/06/09 20:34:50 morsch |
32 | All coding rule violations except RS3 corrected | |
33 | ||
f87cfe57 | 34 | Revision 1.6 1999/11/09 07:38:48 fca |
35 | Changes for compatibility with version 2.23 of ROOT | |
36 | ||
084c1b4a | 37 | Revision 1.5 1999/11/03 17:43:20 fca |
38 | New version from G.Martinez & A.Morsch | |
39 | ||
886b6f73 | 40 | Revision 1.4 1999/09/29 09:24:14 fca |
41 | Introduction of the Copyright and cvs Log | |
42 | ||
4c039060 | 43 | */ |
44 | ||
75c6d54e | 45 | |
fe4da5cc | 46 | #include "AliPythia.h" |
f87cfe57 | 47 | |
fe4da5cc | 48 | ClassImp(AliPythia) |
49 | ||
fe4da5cc | 50 | //_____________________________________________________________________________ |
51 | ||
95b811fe | 52 | AliPythia* AliPythia::fgAliPythia=NULL; |
fe4da5cc | 53 | |
75c6d54e | 54 | AliPythia::AliPythia() |
55 | { | |
95b811fe | 56 | // Default Constructor |
fe4da5cc | 57 | } |
58 | ||
59 | void AliPythia::ProcInit(Process_t process, Float_t energy, StrucFunc_t strucfunc) | |
60 | { | |
f87cfe57 | 61 | // Initialise the process to generate |
fe4da5cc | 62 | fProcess = process; |
63 | fEcms = energy; | |
64 | fStrucFunc = strucfunc; | |
65 | // don't decay p0 | |
95b811fe | 66 | SetMDCY(Pycomp(111),1,0); |
fe4da5cc | 67 | // select structure function |
68 | SetMSTP(52,2); | |
69 | SetMSTP(51,strucfunc); | |
70 | // | |
71 | // Pythia initialisation for selected processes// | |
72 | // | |
73 | // Make MSEL clean | |
74 | // | |
75 | for (Int_t i=1; i<= 200; i++) { | |
76 | SetMSUB(i,0); | |
77 | } | |
78 | // select charm production | |
79 | switch (process) | |
80 | { | |
81 | case charm: | |
82 | SetMSEL(4); | |
83 | // | |
84 | // heavy quark masses | |
85 | ||
86 | SetPMAS(4,1,1.2); | |
87 | ||
88 | // | |
89 | // primordial pT | |
90 | SetMSTP(91,1); | |
e8d05e6c | 91 | SetPARP(91,1.); |
92 | SetPARP(93,5.); | |
fe4da5cc | 93 | // |
94 | break; | |
95 | case beauty: | |
96 | SetMSEL(5); | |
97 | SetPMAS(5,1,4.75); | |
98 | break; | |
99 | case jpsi: | |
100 | SetMSEL(0); | |
101 | // gg->J/Psi g | |
102 | SetMSUB(86,1); | |
103 | break; | |
104 | case jpsi_chi: | |
105 | SetMSEL(0); | |
106 | // gg->J/Psi g | |
107 | SetMSUB(86,1); | |
108 | // gg-> chi_0c g | |
109 | SetMSUB(87,1); | |
110 | // gg-> chi_1c g | |
111 | SetMSUB(88,1); | |
112 | // gg-> chi_2c g | |
113 | SetMSUB(89,1); | |
114 | case charm_unforced: | |
115 | SetMSEL(0); | |
116 | // gq->qg | |
117 | SetMSUB(28,1); | |
118 | // gg->qq | |
119 | SetMSUB(53,1); | |
120 | // gg->gg | |
121 | SetMSUB(68,1); | |
122 | case beauty_unforced: | |
123 | SetMSEL(0); | |
124 | // gq->qg | |
125 | SetMSUB(28,1); | |
126 | // gg->qq | |
127 | SetMSUB(53,1); | |
128 | // gg->gg | |
129 | SetMSUB(68,1); | |
130 | break; | |
75c6d54e | 131 | case mb: |
132 | // Minimum Bias pp-Collisions | |
133 | // | |
134 | // Tuning of parameters descibed in G. Ciapetti and A. Di Ciaccio | |
135 | // Proc. of the LHC Workshop, Aachen 1990, Vol. II p. 155 | |
136 | // | |
137 | // select Pythia min. bias model | |
138 | SetMSEL(2); | |
139 | SetMSUB(92,1); | |
140 | SetMSUB(93,1); | |
141 | SetMSUB(94,1); | |
142 | SetMSUB(95,1); | |
143 | // Multiple interactions switched on | |
144 | SetMSTP(81,1); | |
145 | SetMSTP(82,1); | |
146 | // Low-pT cut-off for hard scattering | |
147 | SetPARP(81,1.9); | |
148 | // model for subsequent non-hardest interaction | |
149 | // 90% gg->gg 10% gg->qq | |
150 | SetPARP(86,0.9); | |
151 | // 90% of gluon interactions have minimum string length | |
152 | SetPARP(85,0.9); | |
fe4da5cc | 153 | } |
154 | // | |
155 | // Initialize PYTHIA | |
95b811fe | 156 | SetMSTP(41,1); |
75c6d54e | 157 | |
95b811fe | 158 | Initialize("CMS","p","p",fEcms); |
fe4da5cc | 159 | } |
160 | ||
95b811fe | 161 | Int_t AliPythia::CheckedLuComp(Int_t kf) |
fe4da5cc | 162 | { |
95b811fe | 163 | // Check Lund particle code (for debugging) |
164 | Int_t kc=Pycomp(kf); | |
165 | printf("\n Lucomp kf,kc %d %d",kf,kc); | |
166 | return kc; | |
fe4da5cc | 167 | } |
168 | ||
811826d8 | 169 | void AliPythia::SetNuclei(Int_t a1, Int_t a2) |
170 | { | |
171 | // Treat protons as inside nuclei with mass numbers a1 and a2 | |
172 | // The MSTP array in the PYPARS common block is used to enable and | |
173 | // select the nuclear structure functions. | |
174 | // MSTP(52) : (D=1) choice of proton and nuclear structure-function library | |
175 | // =1: internal PYTHIA acording to MSTP(51) | |
176 | // =2: PDFLIB proton s.f., with MSTP(51) = 1000xNGROUP+NSET | |
177 | // =3: PDFLIB proton s.f. with nuclar correction: | |
178 | // MSTP( 51) = 1000xNPGROUP+NPSET | |
179 | // MSTP(151) = 1000xNAGROUP+NASET | |
180 | // MSTP(192) : Mass number of nucleus side 1 | |
181 | // MSTP(193) : Mass number of nucleus side 2 | |
182 | ||
183 | SetMSTP(52,3); | |
184 | SetMSTP(191, 1001); | |
185 | SetMSTP(192, a1); | |
186 | SetMSTP(193, a2); | |
187 | } | |
188 | ||
189 | ||
95b811fe | 190 | AliPythia* AliPythia::Instance() |
fe4da5cc | 191 | { |
95b811fe | 192 | if (fgAliPythia) { |
193 | return fgAliPythia; | |
194 | } else { | |
195 | fgAliPythia = new AliPythia(); | |
196 | return fgAliPythia; | |
fe4da5cc | 197 | } |
fe4da5cc | 198 | } |
fe4da5cc | 199 | |
200 | ||
201 | ||
202 | ||
203 | ||
204 |