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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: | |
e40b9538 | 124 | case kElectronEM: |
125 | case kDiElectronEM: | |
47fc6bd5 | 126 | fChildSelect[0] = kElectron; |
e36044d6 | 127 | break; |
2dcb5874 | 128 | case kHardMuons: |
e345c619 | 129 | case kBSemiMuonic: |
e36044d6 | 130 | case kSemiMuonic: |
131 | case kDiMuon: | |
132 | case kBJpsiDiMuon: | |
133 | case kBPsiPrimeDiMuon: | |
134 | case kPiToMu: | |
135 | case kKaToMu: | |
cd159249 | 136 | case kWToMuon: |
137 | case kWToCharmToMuon: | |
2f299526 | 138 | case kZDiMuon: |
f5b581a1 | 139 | case kZDiElectron: |
e36044d6 | 140 | fChildSelect[0]=kMuonMinus; |
141 | break; | |
cd159249 | 142 | case kWToCharm: |
143 | break; | |
e36044d6 | 144 | case kHadronicD: |
af33df34 | 145 | case kHadronicDWithout4Bodies: |
e36044d6 | 146 | fChildSelect[0]=kPiPlus; |
147 | fChildSelect[1]=kKPlus; | |
148 | break; | |
00cb2f27 | 149 | case kPhiKK: |
027677ae | 150 | fChildSelect[0]=kKPlus; |
56d47239 | 151 | break; |
152 | case kBJpsi: | |
00935af2 | 153 | fChildSelect[0]= 443; |
56d47239 | 154 | break; |
00935af2 | 155 | case kChiToJpsiGammaToMuonMuon: |
156 | fChildSelect[0]= 22; | |
157 | fChildSelect[1]= 13; | |
158 | break; | |
159 | case kChiToJpsiGammaToElectronElectron: | |
160 | fChildSelect[0]= 22; | |
161 | fChildSelect[1]= 11; | |
162 | break; | |
d3553100 | 163 | case kLambda: |
199786f7 | 164 | fChildSelect[0]= kProton; |
165 | fChildSelect[1]= 211; | |
166 | break; | |
9610308a | 167 | case kPsiPrimeJpsiDiElectron: |
e40b9538 | 168 | fChildSelect[0]= 211; |
169 | fChildSelect[1]= 11; | |
170 | break; | |
171 | case kGammaEM: | |
172 | fChildSelect[0] = kGamma; | |
173 | break; | |
199786f7 | 174 | case kOmega: |
e36044d6 | 175 | case kAll: |
2b1f8257 | 176 | case kAllMuonic: |
e36044d6 | 177 | case kNoDecay: |
d5f86442 | 178 | case kNoDecayHeavy: |
1fefb2d4 | 179 | case kNoDecayBeauty: |
847af604 | 180 | case kNeutralPion: |
e36044d6 | 181 | break; |
182 | } | |
36d770d9 | 183 | |
184 | if (fZTarget != 0 && fAProjectile != 0) | |
185 | { | |
186 | fDyBoost = - 0.5 * TMath::Log(Double_t(fZProjectile) * Double_t(fATarget) / | |
187 | (Double_t(fZTarget) * Double_t(fAProjectile))); | |
188 | } | |
e36044d6 | 189 | } |
190 | ||
191 | ||
62d0ae06 | 192 | Bool_t AliGenMC::ParentSelected(Int_t ip) const |
e36044d6 | 193 | { |
194 | // True if particle is in list of parent particles to be selected | |
195 | for (Int_t i=0; i<8; i++) | |
196 | { | |
62d0ae06 | 197 | if (fParentSelect.At(i) == ip) return kTRUE; |
e36044d6 | 198 | } |
199 | return kFALSE; | |
200 | } | |
201 | ||
62d0ae06 | 202 | Bool_t AliGenMC::ChildSelected(Int_t ip) const |
e36044d6 | 203 | { |
204 | // True if particle is in list of decay products to be selected | |
205 | for (Int_t i=0; i<5; i++) | |
206 | { | |
62d0ae06 | 207 | if (fChildSelect.At(i) == ip) return kTRUE; |
e36044d6 | 208 | } |
209 | return kFALSE; | |
210 | } | |
211 | ||
62d0ae06 | 212 | Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const |
e36044d6 | 213 | { |
214 | // Perform kinematic selection | |
43a333ec | 215 | Double_t pz = particle->Pz(); |
43a333ec | 216 | Double_t pt = particle->Pt(); |
217 | Double_t p = particle->P(); | |
218 | Double_t theta = particle->Theta(); | |
219 | Double_t mass = particle->GetCalcMass(); | |
220 | Double_t mt2 = pt * pt + mass * mass; | |
221 | Double_t phi = particle->Phi(); | |
d643e262 | 222 | Double_t e = particle->Energy(); |
223 | ||
224 | if (e == 0.) | |
225 | e = TMath::Sqrt(p * p + mass * mass); | |
226 | ||
95450c6d | 227 | |
95450c6d | 228 | Double_t y, y0; |
229 | ||
fef61e14 | 230 | if (TMath::Abs(pz) < e) { |
95450c6d | 231 | y = 0.5*TMath::Log((e+pz)/(e-pz)); |
232 | } else { | |
233 | y = 1.e10; | |
234 | } | |
e36044d6 | 235 | |
95450c6d | 236 | if (mt2) { |
237 | y0 = 0.5*TMath::Log((e+TMath::Abs(pz))*(e+TMath::Abs(pz))/mt2); | |
e36044d6 | 238 | } else { |
95450c6d | 239 | if (TMath::Abs(y) < 1.e10) { |
240 | y0 = y; | |
241 | } else { | |
242 | y0 = 1.e10; | |
243 | } | |
e36044d6 | 244 | } |
95450c6d | 245 | |
246 | y = (pz < 0) ? -y0 : y0; | |
e36044d6 | 247 | |
248 | if (flag == 0) { | |
249 | // | |
250 | // Primary particle cuts | |
251 | // | |
252 | // transverse momentum cut | |
253 | if (pt > fPtMax || pt < fPtMin) { | |
254 | // printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax); | |
255 | return kFALSE; | |
256 | } | |
257 | // | |
258 | // momentum cut | |
259 | if (p > fPMax || p < fPMin) { | |
260 | // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax); | |
261 | return kFALSE; | |
262 | } | |
263 | // | |
264 | // theta cut | |
265 | if (theta > fThetaMax || theta < fThetaMin) { | |
266 | // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax); | |
267 | return kFALSE; | |
268 | } | |
269 | // | |
270 | // rapidity cut | |
271 | if (y > fYMax || y < fYMin) { | |
272 | // printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax); | |
273 | return kFALSE; | |
274 | } | |
275 | // | |
276 | // phi cut | |
277 | if (phi > fPhiMax || phi < fPhiMin) { | |
278 | // printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax); | |
279 | return kFALSE; | |
280 | } | |
281 | } else { | |
282 | // | |
283 | // Decay product cuts | |
284 | // | |
285 | // transverse momentum cut | |
286 | if (pt > fChildPtMax || pt < fChildPtMin) { | |
287 | // printf("\n failed pt cut %f %f %f \n",pt,fChildPtMin,fChildPtMax); | |
288 | return kFALSE; | |
289 | } | |
290 | // | |
291 | // momentum cut | |
292 | if (p > fChildPMax || p < fChildPMin) { | |
293 | // printf("\n failed p cut %f %f %f \n",p,fChildPMin,fChildPMax); | |
294 | return kFALSE; | |
295 | } | |
296 | // | |
297 | // theta cut | |
298 | if (theta > fChildThetaMax || theta < fChildThetaMin) { | |
299 | // printf("\n failed theta cut %f %f %f \n",theta,fChildThetaMin,fChildThetaMax); | |
300 | return kFALSE; | |
301 | } | |
302 | // | |
303 | // rapidity cut | |
304 | if (y > fChildYMax || y < fChildYMin) { | |
305 | // printf("\n failed y cut %f %f %f \n",y,fChildYMin,fChildYMax); | |
306 | return kFALSE; | |
307 | } | |
308 | // | |
309 | // phi cut | |
310 | if (phi > fChildPhiMax || phi < fChildPhiMin) { | |
311 | // printf("\n failed phi cut %f %f %f \n",phi,fChildPhiMin,fChildPhiMax); | |
312 | return kFALSE; | |
313 | } | |
314 | } | |
315 | ||
e36044d6 | 316 | return kTRUE; |
317 | } | |
318 | ||
65de9f86 | 319 | Bool_t AliGenMC::CheckAcceptanceGeometry(Int_t np, TClonesArray* particles) |
320 | { | |
e033748b | 321 | // Check the geometrical acceptance for particle. |
322 | ||
323 | Bool_t check ; | |
324 | Int_t numberOfPdgCodeParticleforAcceptanceCut = 0; | |
325 | Int_t numberOfAcceptedPdgCodeParticleforAcceptanceCut = 0; | |
65de9f86 | 326 | TParticle * particle; |
327 | Int_t i; | |
e033748b | 328 | for (i = 0; i < np; i++) { |
65de9f86 | 329 | particle = (TParticle *) particles->At(i); |
330 | if( TMath::Abs( particle->GetPdgCode() ) == TMath::Abs( fPdgCodeParticleforAcceptanceCut ) ) { | |
e033748b | 331 | numberOfPdgCodeParticleforAcceptanceCut++; |
332 | if (fGeometryAcceptance->Impact(particle)) numberOfAcceptedPdgCodeParticleforAcceptanceCut++; | |
65de9f86 | 333 | } |
334 | } | |
e033748b | 335 | if ( numberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) ) |
336 | check = kTRUE; | |
65de9f86 | 337 | else |
e033748b | 338 | check = kFALSE; |
65de9f86 | 339 | |
e033748b | 340 | return check; |
65de9f86 | 341 | } |
342 | ||
62d0ae06 | 343 | Int_t AliGenMC::CheckPDGCode(Int_t pdgcode) const |
e36044d6 | 344 | { |
345 | // | |
346 | // If the particle is in a diffractive state, then take action accordingly | |
347 | switch (pdgcode) { | |
348 | case 91: | |
349 | return 92; | |
350 | case 110: | |
351 | //rho_diff0 -- difficult to translate, return rho0 | |
352 | return 113; | |
353 | case 210: | |
354 | //pi_diffr+ -- change to pi+ | |
355 | return 211; | |
356 | case 220: | |
357 | //omega_di0 -- change to omega0 | |
358 | return 223; | |
359 | case 330: | |
360 | //phi_diff0 -- return phi0 | |
361 | return 333; | |
362 | case 440: | |
363 | //J/psi_di0 -- return J/psi | |
364 | return 443; | |
365 | case 2110: | |
366 | //n_diffr -- return neutron | |
367 | return 2112; | |
368 | case 2210: | |
369 | //p_diffr+ -- return proton | |
370 | return 2212; | |
371 | } | |
372 | //non diffractive state -- return code unchanged | |
373 | return pdgcode; | |
374 | } | |
3b945a60 | 375 | |
36d770d9 | 376 | void AliGenMC::Boost() |
3b945a60 | 377 | { |
378 | // | |
379 | // Boost cms into LHC lab frame | |
380 | // | |
381 | ||
36d770d9 | 382 | Double_t beta = TMath::TanH(fDyBoost); |
60e55aee | 383 | Double_t gamma = 1./TMath::Sqrt((1.-beta)*(1.+beta)); |
3b945a60 | 384 | Double_t gb = gamma * beta; |
385 | ||
7cdba479 | 386 | // printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma); |
3b945a60 | 387 | |
388 | Int_t i; | |
ea24f998 | 389 | Int_t np = fParticles.GetEntriesFast(); |
3b945a60 | 390 | for (i = 0; i < np; i++) |
391 | { | |
ea24f998 | 392 | TParticle* iparticle = (TParticle*) fParticles.At(i); |
3b945a60 | 393 | |
394 | Double_t e = iparticle->Energy(); | |
395 | Double_t px = iparticle->Px(); | |
396 | Double_t py = iparticle->Py(); | |
397 | Double_t pz = iparticle->Pz(); | |
398 | ||
399 | Double_t eb = gamma * e - gb * pz; | |
400 | Double_t pzb = -gb * e + gamma * pz; | |
401 | ||
402 | iparticle->SetMomentum(px, py, pzb, eb); | |
403 | } | |
404 | } | |
d97fb2bb | 405 | |
7eb751fe | 406 | void AliGenMC::BeamCrossAngle() |
407 | { | |
408 | // Applies a boost in the y-direction in order to take into account the | |
409 | // beam crossing angle | |
410 | ||
411 | Double_t thetaPr0, phiPr0, pyPr2, pzPr2; | |
412 | TVector3 beta; | |
413 | ||
414 | thetaPr0 = fXingAngleY / 2.; | |
415 | phiPr0 = 0; | |
416 | ||
417 | // Momentum of the CMS system | |
418 | pyPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Sin(thetaPr0); | |
419 | pzPr2 = TMath::Sqrt(fEnergyCMS * fEnergyCMS/ 4 - 0.938 * 0.938) * TMath::Cos(thetaPr0); | |
420 | ||
421 | TLorentzVector proj1Vect, proj2Vect, projVect; | |
422 | proj1Vect.SetPxPyPzE(0., pyPr2, pzPr2, fEnergyCMS/2); | |
423 | proj2Vect.SetPxPyPzE(0., pyPr2,-pzPr2, fEnergyCMS/2); | |
424 | projVect = proj1Vect + proj2Vect; | |
425 | beta=(1. / projVect.E()) * (projVect.Vect()); | |
426 | ||
427 | Int_t i; | |
428 | Int_t np = fParticles.GetEntriesFast(); | |
429 | for (i = 0; i < np; i++) | |
430 | { | |
431 | TParticle* iparticle = (TParticle*) fParticles.At(i); | |
432 | ||
433 | Double_t e = iparticle->Energy(); | |
434 | Double_t px = iparticle->Px(); | |
435 | Double_t py = iparticle->Py(); | |
436 | Double_t pz = iparticle->Pz(); | |
437 | ||
438 | TLorentzVector partIn; | |
439 | partIn.SetPxPyPzE(px,py,pz,e); | |
440 | partIn.Boost(beta); | |
441 | iparticle->SetMomentum(partIn.Px(),partIn.Py(),partIn.Pz(),partIn.E()); | |
442 | } | |
443 | } | |
444 | ||
445 | ||
d97fb2bb | 446 | void AliGenMC::AddHeader(AliGenEventHeader* header) |
447 | { | |
448 | // Passes header either to the container or to gAlice | |
449 | if (fContainer) { | |
450 | fContainer->AddHeader(header); | |
451 | } else { | |
452 | gAlice->SetGenEventHeader(header); | |
453 | } | |
454 | } |