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ac3faee4 | 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 | /* $Id$ */ | |
17 | ||
18 | ////////////////////////////////////////////////////////////////////////////// | |
4966b266 | 19 | // |
20 | // AliGeVSimParticle is a helper class for GeVSim (AliGenGeVSim) event generator. | |
21 | // An object of this class represents one particle type and contain | |
22 | // information about particle type thermal parameters. | |
23 | // | |
ac3faee4 | 24 | ////////////////////////////////////////////////////////////////////////////// |
7e4131fc | 25 | // |
4966b266 | 26 | // For examples, parameters and testing macros refer to: |
27 | // http:/home.cern.ch/radomski | |
7e4131fc | 28 | // |
29 | // for more detailed description refer to ALICE NOTE | |
30 | // "GeVSim Monte-Carlo Event Generator" | |
31 | // S.Radosmki, P. Foka. | |
32 | // | |
4966b266 | 33 | // Author: |
34 | // Sylwester Radomski, | |
35 | // GSI, March 2002 | |
7e4131fc | 36 | // |
4966b266 | 37 | // S.Radomski@gsi.de |
38 | // | |
7e4131fc | 39 | //////////////////////////////////////////////////////////////////////////////// |
40 | // | |
41 | // Updated and revised: September 2002, S. Radomski, GSI | |
42 | // | |
43 | //////////////////////////////////////////////////////////////////////////////// | |
44 | ||
4966b266 | 45 | |
46 | #include "TMath.h" | |
7816887f | 47 | #include "AliGeVSimParticle.h" |
48 | ||
925e6570 | 49 | ClassImp(AliGeVSimParticle) |
7816887f | 50 | |
1c56e311 | 51 | |
4966b266 | 52 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
1c56e311 | 53 | AliGeVSimParticle::AliGeVSimParticle(): |
54 | fPDG(0), | |
55 | fModel(0), | |
56 | fN(0), | |
57 | fMultTotal(kTRUE), | |
58 | fIsSetMult(kFALSE), | |
59 | fT(0.), | |
60 | fSigmaY(0.), | |
61 | fExpansion(0.), | |
62 | fIsDirectedSimple(kTRUE), | |
63 | fIsEllipticSimple(kTRUE), | |
64 | fIsEllipticOld(kFALSE) | |
65 | { | |
66 | // Default constructor | |
67 | } | |
7816887f | 68 | |
7e4131fc | 69 | AliGeVSimParticle::AliGeVSimParticle(Int_t pdg, Int_t model, Float_t multiplicity, |
1c56e311 | 70 | Float_t T, Float_t dY, Float_t exp): |
71 | fPDG(pdg), | |
72 | fModel(model), | |
73 | fN(multiplicity), | |
74 | fMultTotal(kTRUE), | |
75 | fIsSetMult(kFALSE), | |
76 | fT(T), | |
77 | fSigmaY(dY), | |
78 | fExpansion(exp), | |
79 | fIsDirectedSimple(kTRUE), | |
80 | fIsEllipticSimple(kTRUE), | |
81 | fIsEllipticOld(kFALSE) | |
82 | { | |
4966b266 | 83 | // |
7e4131fc | 84 | // pdg - Particle type code in PDG standard (see: http://pdg.lbl.gov) |
85 | // model - momentum distribution model (1 - 7) | |
86 | // multiplicity - multiplicity of particle type | |
87 | // T - Inverse slope parameter ("temperature") | |
88 | // dY - Raridity Width (only for model 1) | |
89 | // exp - expansion velocity (only for model 4) | |
4966b266 | 90 | fV1[0] = fV1[1] = fV1[2] = fV1[3] = 0.; |
91 | fV2[0] = fV2[1] = fV2[2] = 0.; | |
7816887f | 92 | } |
93 | ||
4966b266 | 94 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
7816887f | 95 | |
1c56e311 | 96 | AliGeVSimParticle::AliGeVSimParticle(Int_t pdg, Int_t model, Float_t multiplicity): |
97 | fPDG(pdg), | |
98 | fModel(model), | |
99 | fN(multiplicity), | |
100 | fMultTotal(kTRUE), | |
101 | fIsSetMult(kFALSE), | |
102 | fT(0.), | |
103 | fSigmaY(0.), | |
104 | fExpansion(0.), | |
105 | fIsDirectedSimple(kTRUE), | |
106 | fIsEllipticSimple(kTRUE), | |
107 | fIsEllipticOld(kFALSE) | |
108 | { | |
4966b266 | 109 | // |
7e4131fc | 110 | // pdg - Particle type code in PDG standard (see: http://pdg.lbl.gov) |
111 | // | |
112 | // Note that multiplicity can be interpreted by GeVSim | |
113 | // either as Total multiplicity in the acceptance or dN/dY | |
4966b266 | 114 | // |
4966b266 | 115 | fV1[0] = fV1[1] = fV1[2] = fV1[3] = 0.; |
116 | fV2[0] = fV2[1] = fV2[2] = 0.; | |
7e4131fc | 117 | } |
118 | ||
119 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
120 | ||
121 | void AliGeVSimParticle::SetModel(Int_t model) { | |
122 | // | |
123 | // Set Model (1-7) | |
124 | // For details about standard and custom models refer to ALICE NOTE | |
125 | // | |
126 | ||
127 | if (model < 1 || model > 7) | |
128 | Error("SetModel","Model Id ( %d ) out of range [1..7]", model); | |
129 | ||
130 | fModel = model; | |
131 | } | |
132 | ||
133 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
134 | ||
135 | void AliGeVSimParticle::SetMultiplicity(Float_t mult) { | |
136 | // | |
137 | // Set multiplicity. The value is interpreted either as a total multiplciity | |
138 | // in the acceptance or as a multiplicity density - dN/dY at midrapidity | |
139 | // | |
140 | ||
141 | fN = mult; | |
142 | } | |
143 | ||
144 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
145 | ||
146 | void AliGeVSimParticle::SetMultTotal(Bool_t isTotal) { | |
147 | // | |
148 | // Switch between total multiplicity (kTRUE) and | |
149 | // multiplciity density (kFALSE) | |
150 | // | |
151 | // If this method is used its overrides mode in AliGenGeVSim | |
152 | // | |
153 | ||
154 | fMultTotal = isTotal; | |
155 | fIsSetMult = kTRUE; | |
156 | } | |
157 | ||
158 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
159 | ||
160 | void AliGeVSimParticle::SetDirectedSimple(Float_t v1) { | |
161 | // | |
162 | // Set directed flow coefficient to a value independent | |
163 | // of transverse momentum and rapidity | |
164 | // | |
165 | ||
166 | fV1[0] = v1; | |
167 | fIsDirectedSimple = kTRUE; | |
168 | } | |
169 | ||
170 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
171 | ||
172 | void AliGeVSimParticle::SetEllipticSimple(Float_t v2) { | |
173 | // | |
174 | // Set elliptic flow coefficient to a value independent | |
175 | // of transverse momentum and rapidity | |
176 | // | |
177 | ||
178 | fV2[0] = v2; | |
179 | fIsEllipticSimple = kTRUE; | |
180 | } | |
181 | ||
182 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
183 | ||
ac3faee4 | 184 | Bool_t AliGeVSimParticle::IsFlowSimple() const |
185 | { | |
7e4131fc | 186 | // |
187 | // Function used by AliGenGeVSim | |
188 | // | |
189 | // Returns true if both Elliptic and Directed flow has a simple model. | |
190 | // If at least one is parametrised returns false. | |
191 | // | |
192 | ||
193 | return (fIsDirectedSimple && fIsEllipticSimple); | |
7816887f | 194 | } |
195 | ||
4966b266 | 196 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
197 | ||
7e4131fc | 198 | void AliGeVSimParticle::SetDirectedParam(Float_t v11, Float_t v12, Float_t v13, Float_t v14) { |
4966b266 | 199 | // |
7e4131fc | 200 | // Set parameters for Directed Flow |
201 | // Actual flow coefficient is calculated as follows | |
4966b266 | 202 | // |
203 | // V1(Pt,Y) = (V11 + V12*Pt) * sign(Y) * (V13 + V14 * Y^3) | |
204 | // | |
205 | // where sign = 1 for Y > 0 and -1 for Y < 0 | |
206 | // | |
207 | // Defaults values | |
208 | // v12 = v14 = 0 | |
209 | // v13 = 1 | |
210 | // | |
4966b266 | 211 | |
212 | fV1[0] = v11; | |
213 | fV1[1] = v12; | |
214 | fV1[2] = v13; | |
215 | fV1[3] = v14; | |
7e4131fc | 216 | |
217 | fIsDirectedSimple = kFALSE; | |
4966b266 | 218 | } |
7816887f | 219 | |
4966b266 | 220 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
221 | ||
7e4131fc | 222 | void AliGeVSimParticle::SetEllipticParam(Float_t v21, Float_t pTmax, Float_t v22) { |
4966b266 | 223 | // |
7e4131fc | 224 | // Set parameters for Elliptic Flow |
225 | // Actual flow coefficient is calculated as follows | |
226 | // | |
227 | // pTmax is in GeV | |
228 | // v21 - flow value at saturation | |
229 | // | |
230 | // | |
231 | // V2 = v21 * (pT/pTMax ) * exp (-v22 * y^2) where pT <= pTmax | |
232 | // v21 * exp (-v22 * y^2) where pT > pTmax | |
4966b266 | 233 | // |
4966b266 | 234 | // Default values: |
7e4131fc | 235 | // v22 = 0 |
4966b266 | 236 | // |
7e4131fc | 237 | // The parametrisation is suitable for relativistic particles |
238 | // eg. Pions (at RHIC energies) | |
4966b266 | 239 | // |
7e4131fc | 240 | |
241 | ||
242 | fV2[0] = v21; | |
243 | fV2[1] = pTmax; | |
244 | fV2[2] = v22; | |
245 | ||
246 | fIsEllipticSimple = kFALSE; | |
247 | fIsEllipticOld = kFALSE; | |
248 | } | |
249 | ||
250 | //////////////////////////////////////////////////////////////////////////////////////////////////// | |
251 | ||
252 | void AliGeVSimParticle::SetEllipticOld(Float_t v21, Float_t v22, Float_t v23) { | |
253 | // | |
254 | // Set parameters for Elliptic Flow | |
255 | // Actual flow coefficient is calculated as follows | |
256 | // | |
257 | // V2 = (V21 + V22 pT^2) * exp (-v22 * y^2) | |
258 | // | |
259 | // The parameterisation is suitable for heavy particles: proton, kaon | |
260 | // | |
261 | ||
4966b266 | 262 | fV2[0] = v21; |
263 | fV2[1] = v22; | |
264 | fV2[2] = v23; | |
7e4131fc | 265 | |
266 | fIsEllipticSimple = kFALSE; | |
267 | fIsEllipticOld = kTRUE; | |
4966b266 | 268 | } |
7816887f | 269 | |
4966b266 | 270 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
7816887f | 271 | |
4966b266 | 272 | Float_t AliGeVSimParticle::GetDirectedFlow(Float_t pt, Float_t y) { |
273 | // | |
274 | // Return coefficient of a directed flow for a given pt and y. | |
7e4131fc | 275 | // For coefficient calculation method refer to SetDirectedParam() |
4966b266 | 276 | // |
277 | ||
7e4131fc | 278 | if (fIsDirectedSimple) return fV1[0]; |
279 | ||
4966b266 | 280 | Float_t v; |
281 | ||
635be086 | 282 | v = (fV1[0] + fV1[1]* pt) * TMath::Sign((Float_t)1.,y) * |
4966b266 | 283 | (fV1[2] + fV1[3] * TMath::Abs(y*y*y) ); |
7816887f | 284 | |
4966b266 | 285 | return v; |
286 | } | |
7816887f | 287 | |
4966b266 | 288 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
7816887f | 289 | |
4966b266 | 290 | Float_t AliGeVSimParticle::GetEllipticFlow(Float_t pt, Float_t y) { |
291 | // | |
292 | // Return coefficient of a elliptic flow for a given pt and y. | |
7e4131fc | 293 | // For coefficient calculation method refer to SetEllipticParam() |
4966b266 | 294 | // |
7e4131fc | 295 | |
296 | if (fIsEllipticSimple) return fV2[0]; | |
297 | ||
298 | if (fIsEllipticOld) { | |
4966b266 | 299 | |
7e4131fc | 300 | // old parametrisation |
301 | return (fV2[0]+fV2[1]*pt*pt) * TMath::Exp(-fV2[2]*y*y); | |
7816887f | 302 | |
7e4131fc | 303 | } else { |
7816887f | 304 | |
7e4131fc | 305 | // new "pionic" parameterisation |
306 | if (pt < fV2[1]) return ( (pt / fV2[1]) * fV2[0] * TMath::Exp(-fV2[2]*y*y) ); | |
307 | else return ( fV2[0] * TMath::Exp(-fV2[2]*y*y) ); | |
308 | } | |
4966b266 | 309 | } |
7816887f | 310 | |
4966b266 | 311 | //////////////////////////////////////////////////////////////////////////////////////////////////// |
7816887f | 312 | |
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