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e36044d6 | 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 | ||
88cb7938 | 16 | /* $Id$ */ |
e36044d6 | 17 | |
62d0ae06 | 18 | // Base class for generators using external MC generators. |
19 | // For example AliGenPythia using Pythia. | |
20 | // Provides basic functionality: setting of kinematic cuts on | |
21 | // decay products and particle selection. | |
22 | // andreas.morsch@cern.ch | |
23 | ||
ac3faee4 | 24 | #include <TClonesArray.h> |
65de9f86 | 25 | #include <TMath.h> |
116cbefd | 26 | #include <TPDGCode.h> |
e36044d6 | 27 | #include <TParticle.h> |
7eb751fe | 28 | #include <TLorentzVector.h> |
29 | #include <TVector3.h> | |
e36044d6 | 30 | |
116cbefd | 31 | #include "AliGenMC.h" |
d97fb2bb | 32 | #include "AliRun.h" |
ac3faee4 | 33 | #include "AliGeometry.h" |
116cbefd | 34 | |
198bb1c7 | 35 | ClassImp(AliGenMC) |
e36044d6 | 36 | |
37 | AliGenMC::AliGenMC() | |
1c56e311 | 38 | :AliGenerator(), |
969a210b | 39 | fParticles("TParticle", 1000), |
1c56e311 | 40 | fParentSelect(8), |
41 | fChildSelect(8), | |
42 | fCutOnChild(0), | |
43 | fChildPtMin(0.), | |
44 | fChildPtMax(1.e10), | |
45 | fChildPMin(0.), | |
46 | fChildPMax(1.e10), | |
47 | fChildPhiMin(0.), | |
48 | fChildPhiMax(2. * TMath::Pi()), | |
49 | fChildThetaMin(0.), | |
50 | fChildThetaMax(TMath::Pi()), | |
51 | fChildYMin(-12.), | |
52 | fChildYMax(12.), | |
53 | fXingAngleX(0.), | |
54 | fXingAngleY(0.), | |
55 | fForceDecay(kAll), | |
56 | fMaxLifeTime(1.e-15), | |
1c56e311 | 57 | fDyBoost(0.), |
58 | fGeometryAcceptance(0), | |
59 | fPdgCodeParticleforAcceptanceCut(0), | |
d97fb2bb | 60 | fNumberOfAcceptedParticles(0), |
e7c989e4 | 61 | fNprimaries(0) |
e36044d6 | 62 | { |
63 | // Default Constructor | |
e7c989e4 | 64 | fAProjectile = 1; |
65 | fZProjectile = 1; | |
66 | fATarget = 1; | |
67 | fZTarget = 1; | |
68 | fProjectile = "P"; | |
69 | fTarget = "P"; | |
e36044d6 | 70 | } |
71 | ||
72 | AliGenMC::AliGenMC(Int_t npart) | |
1c56e311 | 73 | :AliGenerator(npart), |
ea24f998 | 74 | fParticles("TParticle", 1000), |
1c56e311 | 75 | fParentSelect(8), |
76 | fChildSelect(8), | |
77 | fCutOnChild(0), | |
78 | fChildPtMin(0.), | |
79 | fChildPtMax(1.e10), | |
80 | fChildPMin(0.), | |
81 | fChildPMax(1.e10), | |
82 | fChildPhiMin(0.), | |
83 | fChildPhiMax(2. * TMath::Pi()), | |
84 | fChildThetaMin(0.), | |
85 | fChildThetaMax(TMath::Pi()), | |
86 | fChildYMin(-12.), | |
87 | fChildYMax(12.), | |
88 | fXingAngleX(0.), | |
89 | fXingAngleY(0.), | |
90 | fForceDecay(kAll), | |
91 | fMaxLifeTime(1.e-15), | |
1c56e311 | 92 | fDyBoost(0.), |
93 | fGeometryAcceptance(0), | |
94 | fPdgCodeParticleforAcceptanceCut(0), | |
d97fb2bb | 95 | fNumberOfAcceptedParticles(0), |
e7c989e4 | 96 | fNprimaries(0) |
e36044d6 | 97 | { |
98 | // Constructor | |
e36044d6 | 99 | // |
e7c989e4 | 100 | fAProjectile = 1; |
101 | fZProjectile = 1; | |
102 | fATarget = 1; | |
103 | fZTarget = 1; | |
104 | fProjectile = "P"; | |
105 | fTarget = "P"; | |
106 | for (Int_t i=0; i<8; i++) fParentSelect[i]=fChildSelect[i]=0; | |
e36044d6 | 107 | } |
108 | ||
e36044d6 | 109 | AliGenMC::~AliGenMC() |
110 | { | |
111 | // Destructor | |
112 | } | |
113 | ||
114 | void AliGenMC::Init() | |
115 | { | |
116 | // | |
117 | // Initialization | |
118 | switch (fForceDecay) { | |
e345c619 | 119 | case kBSemiElectronic: |
e36044d6 | 120 | case kSemiElectronic: |
121 | case kDiElectron: | |
122 | case kBJpsiDiElectron: | |
123 | case kBPsiPrimeDiElectron: | |
47fc6bd5 | 124 | fChildSelect[0] = kElectron; |
e36044d6 | 125 | break; |
2dcb5874 | 126 | case kHardMuons: |
e345c619 | 127 | case kBSemiMuonic: |
e36044d6 | 128 | case kSemiMuonic: |
129 | case kDiMuon: | |
130 | case kBJpsiDiMuon: | |
131 | case kBPsiPrimeDiMuon: | |
132 | case kPiToMu: | |
133 | case kKaToMu: | |
cd159249 | 134 | case kWToMuon: |
135 | case kWToCharmToMuon: | |
2f299526 | 136 | case kZDiMuon: |
f5b581a1 | 137 | case kZDiElectron: |
e36044d6 | 138 | fChildSelect[0]=kMuonMinus; |
139 | break; | |
cd159249 | 140 | case kWToCharm: |
141 | break; | |
e36044d6 | 142 | case kHadronicD: |
af33df34 | 143 | case kHadronicDWithout4Bodies: |
e36044d6 | 144 | fChildSelect[0]=kPiPlus; |
145 | fChildSelect[1]=kKPlus; | |
146 | break; | |
00cb2f27 | 147 | case kPhiKK: |
027677ae | 148 | fChildSelect[0]=kKPlus; |
56d47239 | 149 | break; |
150 | case kBJpsi: | |
00935af2 | 151 | fChildSelect[0]= 443; |
56d47239 | 152 | break; |
00935af2 | 153 | case kChiToJpsiGammaToMuonMuon: |
154 | fChildSelect[0]= 22; | |
155 | fChildSelect[1]= 13; | |
156 | break; | |
157 | case kChiToJpsiGammaToElectronElectron: | |
158 | fChildSelect[0]= 22; | |
159 | fChildSelect[1]= 11; | |
160 | break; | |
d3553100 | 161 | case kLambda: |
199786f7 | 162 | fChildSelect[0]= kProton; |
163 | fChildSelect[1]= 211; | |
164 | break; | |
9610308a | 165 | case kPsiPrimeJpsiDiElectron: |
166 | fChildSelect[0]= 211; | |
167 | fChildSelect[1]= 11; | |
168 | break; | |
199786f7 | 169 | case kOmega: |
e36044d6 | 170 | case kAll: |
2b1f8257 | 171 | case kAllMuonic: |
e36044d6 | 172 | case kNoDecay: |
d5f86442 | 173 | case kNoDecayHeavy: |
1fefb2d4 | 174 | case kNoDecayBeauty: |
847af604 | 175 | case kNeutralPion: |
e36044d6 | 176 | break; |
177 | } | |
36d770d9 | 178 | |
179 | if (fZTarget != 0 && fAProjectile != 0) | |
180 | { | |
181 | fDyBoost = - 0.5 * TMath::Log(Double_t(fZProjectile) * Double_t(fATarget) / | |
182 | (Double_t(fZTarget) * Double_t(fAProjectile))); | |
183 | } | |
e36044d6 | 184 | } |
185 | ||
186 | ||
62d0ae06 | 187 | Bool_t AliGenMC::ParentSelected(Int_t ip) const |
e36044d6 | 188 | { |
189 | // True if particle is in list of parent particles to be selected | |
190 | for (Int_t i=0; i<8; i++) | |
191 | { | |
62d0ae06 | 192 | if (fParentSelect.At(i) == ip) return kTRUE; |
e36044d6 | 193 | } |
194 | return kFALSE; | |
195 | } | |
196 | ||
62d0ae06 | 197 | Bool_t AliGenMC::ChildSelected(Int_t ip) const |
e36044d6 | 198 | { |
199 | // True if particle is in list of decay products to be selected | |
200 | for (Int_t i=0; i<5; i++) | |
201 | { | |
62d0ae06 | 202 | if (fChildSelect.At(i) == ip) return kTRUE; |
e36044d6 | 203 | } |
204 | return kFALSE; | |
205 | } | |
206 | ||
62d0ae06 | 207 | Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const |
e36044d6 | 208 | { |
209 | // Perform kinematic selection | |
43a333ec | 210 | Double_t pz = particle->Pz(); |
43a333ec | 211 | Double_t pt = particle->Pt(); |
212 | Double_t p = particle->P(); | |
213 | Double_t theta = particle->Theta(); | |
214 | Double_t mass = particle->GetCalcMass(); | |
215 | Double_t mt2 = pt * pt + mass * mass; | |
216 | Double_t phi = particle->Phi(); | |
d643e262 | 217 | Double_t e = particle->Energy(); |
218 | ||
219 | if (e == 0.) | |
220 | e = TMath::Sqrt(p * p + mass * mass); | |
221 | ||
95450c6d | 222 | |
95450c6d | 223 | Double_t y, y0; |
224 | ||
fef61e14 | 225 | if (TMath::Abs(pz) < e) { |
95450c6d | 226 | y = 0.5*TMath::Log((e+pz)/(e-pz)); |
227 | } else { | |
228 | y = 1.e10; | |
229 | } | |
e36044d6 | 230 | |
95450c6d | 231 | if (mt2) { |
232 | y0 = 0.5*TMath::Log((e+TMath::Abs(pz))*(e+TMath::Abs(pz))/mt2); | |
e36044d6 | 233 | } else { |
95450c6d | 234 | if (TMath::Abs(y) < 1.e10) { |
235 | y0 = y; | |
236 | } else { | |
237 | y0 = 1.e10; | |
238 | } | |
e36044d6 | 239 | } |
95450c6d | 240 | |
241 | y = (pz < 0) ? -y0 : y0; | |
e36044d6 | 242 | |
243 | if (flag == 0) { | |
244 | // | |
245 | // Primary particle cuts | |
246 | // | |
247 | // transverse momentum cut | |
248 | if (pt > fPtMax || pt < fPtMin) { | |
249 | // printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax); | |
250 | return kFALSE; | |
251 | } | |
252 | // | |
253 | // momentum cut | |
254 | if (p > fPMax || p < fPMin) { | |
255 | // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax); | |
256 | return kFALSE; | |
257 | } | |
258 | // | |
259 | // theta cut | |
260 | if (theta > fThetaMax || theta < fThetaMin) { | |
261 | // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax); | |
262 | return kFALSE; | |
263 | } | |
264 | // | |
265 | // rapidity cut | |
266 | if (y > fYMax || y < fYMin) { | |
267 | // printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax); | |
268 | return kFALSE; | |
269 | } | |
270 | // | |
271 | // phi cut | |
272 | if (phi > fPhiMax || phi < fPhiMin) { | |
273 | // printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax); | |
274 | return kFALSE; | |
275 | } | |
276 | } else { | |
277 | // | |
278 | // Decay product cuts | |
279 | // | |
280 | // transverse momentum cut | |
281 | if (pt > fChildPtMax || pt < fChildPtMin) { | |
282 | // printf("\n failed pt cut %f %f %f \n",pt,fChildPtMin,fChildPtMax); | |
283 | return kFALSE; | |
284 | } | |
285 | // | |
286 | // momentum cut | |
287 | if (p > fChildPMax || p < fChildPMin) { | |
288 | // printf("\n failed p cut %f %f %f \n",p,fChildPMin,fChildPMax); | |
289 | return kFALSE; | |
290 | } | |
291 | // | |
292 | // theta cut | |
293 | if (theta > fChildThetaMax || theta < fChildThetaMin) { | |
294 | // printf("\n failed theta cut %f %f %f \n",theta,fChildThetaMin,fChildThetaMax); | |
295 | return kFALSE; | |
296 | } | |
297 | // | |
298 | // rapidity cut | |
299 | if (y > fChildYMax || y < fChildYMin) { | |
300 | // printf("\n failed y cut %f %f %f \n",y,fChildYMin,fChildYMax); | |
301 | return kFALSE; | |
302 | } | |
303 | // | |
304 | // phi cut | |
305 | if (phi > fChildPhiMax || phi < fChildPhiMin) { | |
306 | // printf("\n failed phi cut %f %f %f \n",phi,fChildPhiMin,fChildPhiMax); | |
307 | return kFALSE; | |
308 | } | |
309 | } | |
310 | ||
e36044d6 | 311 | return kTRUE; |
312 | } | |
313 | ||
65de9f86 | 314 | Bool_t AliGenMC::CheckAcceptanceGeometry(Int_t np, TClonesArray* particles) |
315 | { | |
e033748b | 316 | // Check the geometrical acceptance for particle. |
317 | ||
318 | Bool_t check ; | |
319 | Int_t numberOfPdgCodeParticleforAcceptanceCut = 0; | |
320 | Int_t numberOfAcceptedPdgCodeParticleforAcceptanceCut = 0; | |
65de9f86 | 321 | TParticle * particle; |
322 | Int_t i; | |
e033748b | 323 | for (i = 0; i < np; i++) { |
65de9f86 | 324 | particle = (TParticle *) particles->At(i); |
325 | if( TMath::Abs( particle->GetPdgCode() ) == TMath::Abs( fPdgCodeParticleforAcceptanceCut ) ) { | |
e033748b | 326 | numberOfPdgCodeParticleforAcceptanceCut++; |
327 | if (fGeometryAcceptance->Impact(particle)) numberOfAcceptedPdgCodeParticleforAcceptanceCut++; | |
65de9f86 | 328 | } |
329 | } | |
e033748b | 330 | if ( numberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) ) |
331 | check = kTRUE; | |
65de9f86 | 332 | else |
e033748b | 333 | check = kFALSE; |
65de9f86 | 334 | |
e033748b | 335 | return check; |
65de9f86 | 336 | } |
337 | ||
62d0ae06 | 338 | Int_t AliGenMC::CheckPDGCode(Int_t pdgcode) const |
e36044d6 | 339 | { |
340 | // | |
341 | // If the particle is in a diffractive state, then take action accordingly | |
342 | switch (pdgcode) { | |
343 | case 91: | |
344 | return 92; | |
345 | case 110: | |
346 | //rho_diff0 -- difficult to translate, return rho0 | |
347 | return 113; | |
348 | case 210: | |
349 | //pi_diffr+ -- change to pi+ | |
350 | return 211; | |
351 | case 220: | |
352 | //omega_di0 -- change to omega0 | |
353 | return 223; | |
354 | case 330: | |
355 | //phi_diff0 -- return phi0 | |
356 | return 333; | |
357 | case 440: | |
358 | //J/psi_di0 -- return J/psi | |
359 | return 443; | |
360 | case 2110: | |
361 | //n_diffr -- return neutron | |
362 | return 2112; | |
363 | case 2210: | |
364 | //p_diffr+ -- return proton | |
365 | return 2212; | |
366 | } | |
367 | //non diffractive state -- return code unchanged | |
368 | return pdgcode; | |
369 | } | |
3b945a60 | 370 | |
36d770d9 | 371 | void AliGenMC::Boost() |
3b945a60 | 372 | { |
373 | // | |
374 | // Boost cms into LHC lab frame | |
375 | // | |
376 | ||
36d770d9 | 377 | Double_t beta = TMath::TanH(fDyBoost); |
60e55aee | 378 | Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta)); |
3b945a60 | 379 | Double_t gb = gamma * beta; |
380 | ||
7cdba479 | 381 | // printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma); |
3b945a60 | 382 | |
383 | Int_t i; | |
ea24f998 | 384 | Int_t np = fParticles.GetEntriesFast(); |
3b945a60 | 385 | for (i = 0; i < np; i++) |
386 | { | |
ea24f998 | 387 | TParticle* iparticle = (TParticle*) fParticles.At(i); |
3b945a60 | 388 | |
389 | Double_t e = iparticle->Energy(); | |
390 | Double_t px = iparticle->Px(); | |
391 | Double_t py = iparticle->Py(); | |
392 | Double_t pz = iparticle->Pz(); | |
393 | ||
394 | Double_t eb = gamma * e - gb * pz; | |
395 | Double_t pzb = -gb * e + gamma * pz; | |
396 | ||
397 | iparticle->SetMomentum(px, py, pzb, eb); | |
398 | } | |
399 | } | |
d97fb2bb | 400 | |
7eb751fe | 401 | void AliGenMC::BeamCrossAngle() |
402 | { | |
403 | // Applies a boost in the y-direction in order to take into account the | |
404 | // beam crossing angle | |
405 | ||
406 | Double_t thetaPr0, phiPr0, pyPr2, pzPr2; | |
407 | TVector3 beta; | |
408 | ||
409 | thetaPr0 = fXingAngleY / 2.; | |
410 | phiPr0 = 0; | |
411 | ||
412 | // Momentum of the CMS system | |
413 | pyPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Sin(thetaPr0); | |
414 | pzPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Cos(thetaPr0); | |
415 | ||
416 | TLorentzVector proj1Vect, proj2Vect, projVect; | |
417 | proj1Vect.SetPxPyPzE(0., pyPr2, pzPr2, fEnergyCMS/2); | |
418 | proj2Vect.SetPxPyPzE(0., pyPr2,-pzPr2, fEnergyCMS/2); | |
419 | projVect = proj1Vect + proj2Vect; | |
420 | beta=(1. / projVect.E()) * (projVect.Vect()); | |
421 | ||
422 | Int_t i; | |
423 | Int_t np = fParticles.GetEntriesFast(); | |
424 | for (i = 0; i < np; i++) | |
425 | { | |
426 | TParticle* iparticle = (TParticle*) fParticles.At(i); | |
427 | ||
428 | Double_t e = iparticle->Energy(); | |
429 | Double_t px = iparticle->Px(); | |
430 | Double_t py = iparticle->Py(); | |
431 | Double_t pz = iparticle->Pz(); | |
432 | ||
433 | TLorentzVector partIn; | |
434 | partIn.SetPxPyPzE(px,py,pz,e); | |
435 | partIn.Boost(beta); | |
436 | iparticle->SetMomentum(partIn.Px(),partIn.Py(),partIn.Pz(),partIn.E()); | |
437 | } | |
438 | } | |
439 | ||
440 | ||
d97fb2bb | 441 | void AliGenMC::AddHeader(AliGenEventHeader* header) |
442 | { | |
443 | // Passes header either to the container or to gAlice | |
444 | if (fContainer) { | |
445 | fContainer->AddHeader(header); | |
446 | } else { | |
447 | gAlice->SetGenEventHeader(header); | |
448 | } | |
449 | } |