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948d10f4 | 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 | // Implementation of AliDecayer using Pythia8 | |
19 | // Author: andreas.morsch@cern.ch | |
20 | #include <TMath.h> | |
21 | #include <TPDGCode.h> | |
22 | #include <TPythia8.h> | |
23 | #include "AliDecayerPythia8.h" | |
24 | #include "ParticleData.h" | |
25 | ||
26 | ClassImp(AliDecayerPythia8) | |
27 | ||
28 | AliDecayerPythia8::AliDecayerPythia8(): | |
29 | TPythia8Decayer(), | |
30 | fDecay(kAll), | |
31 | fHeavyFlavour(kTRUE) | |
32 | { | |
33 | // Constructor | |
34 | } | |
35 | ||
36 | void AliDecayerPythia8::ForceDecay() | |
37 | { | |
38 | // | |
39 | // Force a particle decay mode | |
40 | // Switch heavy flavour production off if requested | |
41 | if (!fHeavyFlavour) SwitchOffHeavyFlavour(); | |
42 | // | |
43 | Decay_t decay = fDecay; | |
44 | TPythia8::Instance()->ReadString("HadronLevel:Decay = on"); | |
45 | ||
46 | if (decay == kNoDecayHeavy) return; | |
47 | ||
48 | // | |
49 | // select mode | |
50 | Int_t products[2]; | |
51 | Int_t mult[2]; | |
52 | Int_t products1[3]; | |
53 | Int_t mult1[3]; | |
54 | ||
55 | switch (decay) | |
56 | { | |
57 | case kHardMuons: | |
58 | products1[0] = 13; | |
59 | products1[1] = 443; | |
60 | products1[2] = 100443; | |
61 | mult1[0] = 1; | |
62 | mult1[1] = 1; | |
63 | mult1[2] = 1; | |
64 | ForceParticleDecay( 511, products1, mult1, 3); | |
65 | ForceParticleDecay( 521, products1, mult1, 3); | |
66 | ForceParticleDecay( 531, products1, mult1, 3); | |
67 | ForceParticleDecay( 5122, products1, mult1, 3); | |
68 | ForceParticleDecay( 5132, products1, mult1, 3); | |
69 | ForceParticleDecay( 5232, products1, mult1, 3); | |
70 | ForceParticleDecay( 5332, products1, mult1, 3); | |
71 | ForceParticleDecay( 100443, 443, 1); // Psi' -> J/Psi X | |
72 | ForceParticleDecay( 443, 13, 2); // J/Psi -> mu+ mu- | |
73 | ForceParticleDecay( 411,13,1); // D+/- | |
74 | ForceParticleDecay( 421,13,1); // D0 | |
75 | ForceParticleDecay( 431,13,1); // D_s | |
76 | ForceParticleDecay( 4122,13,1); // Lambda_c | |
77 | ForceParticleDecay( 4132,13,1); // Xsi_c | |
78 | ForceParticleDecay( 4232,13,1); // Sigma_c | |
79 | ForceParticleDecay( 4332,13,1); // Omega_c | |
80 | break; | |
81 | case kChiToJpsiGammaToMuonMuon: | |
82 | products[0] = 443; | |
83 | products[1] = 22; | |
84 | mult[0] = 1; | |
85 | mult[1] = 1; | |
86 | ForceParticleDecay( 20443, products, mult, 2); // Chi_1c -> J/Psi Gamma | |
87 | ForceParticleDecay( 445, products, mult, 2); // Chi_2c -> J/Psi Gamma | |
88 | ForceParticleDecay( 443, 13, 2); // J/Psi -> mu+ mu- | |
89 | break; | |
90 | case kChiToJpsiGammaToElectronElectron: | |
91 | products[0] = 443; | |
92 | products[1] = 22; | |
93 | mult[0] = 1; | |
94 | mult[1] = 1; | |
95 | ForceParticleDecay( 20443, products, mult, 2); // Chi_1c -> J/Psi Gamma | |
96 | ForceParticleDecay( 445, products, mult, 2); // Chi_2c -> J/Psi Gamma | |
97 | ForceParticleDecay( 443, 11, 2); // J/Psi -> e+ e- | |
98 | break; | |
99 | ||
100 | case kBSemiMuonic: | |
101 | ForceParticleDecay( 511,13,1); // B0 | |
102 | ForceParticleDecay( 521,13,1); // B+/- | |
103 | ForceParticleDecay( 531,13,1); // B_s | |
104 | ForceParticleDecay( 5122,13,1); // Lambda_b | |
105 | ForceParticleDecay( 5132,13,1); // Xsi_b | |
106 | ForceParticleDecay( 5232,13,1); // Sigma_b | |
107 | ForceParticleDecay( 5332,13,1); // Omega_b | |
108 | break; | |
109 | case kSemiMuonic: | |
110 | ForceParticleDecay( 411,13,1); // D+/- | |
111 | ForceParticleDecay( 421,13,1); // D0 | |
112 | ForceParticleDecay( 431,13,1); // D_s | |
113 | ForceParticleDecay( 4122,13,1); // Lambda_c | |
114 | ForceParticleDecay( 4132,13,1); // Xsi_c | |
115 | ForceParticleDecay( 4232,13,1); // Sigma_c | |
116 | ForceParticleDecay( 4332,13,1); // Omega_c | |
117 | ForceParticleDecay( 511,13,1); // B0 | |
118 | ForceParticleDecay( 521,13,1); // B+/- | |
119 | ForceParticleDecay( 531,13,1); // B_s | |
120 | ForceParticleDecay( 5122,13,1); // Lambda_b | |
121 | ForceParticleDecay( 5132,13,1); // Xsi_b | |
122 | ForceParticleDecay( 5232,13,1); // Sigma_b | |
123 | ForceParticleDecay( 5332,13,1); // Omega_b | |
124 | break; | |
125 | case kDiMuon: | |
126 | ForceParticleDecay( 113,13,2); // rho | |
127 | ForceParticleDecay( 221,13,2); // eta | |
128 | ForceParticleDecay( 223,13,2); // omega | |
129 | ForceParticleDecay( 333,13,2); // phi | |
130 | ForceParticleDecay( 443,13,2); // J/Psi | |
131 | ForceParticleDecay(100443,13,2);// Psi' | |
132 | ForceParticleDecay( 553,13,2); // Upsilon | |
133 | ForceParticleDecay(100553,13,2);// Upsilon' | |
134 | ForceParticleDecay(200553,13,2);// Upsilon'' | |
135 | break; | |
136 | case kBSemiElectronic: | |
137 | ForceParticleDecay( 511,11,1); // B0 | |
138 | ForceParticleDecay( 521,11,1); // B+/- | |
139 | ForceParticleDecay( 531,11,1); // B_s | |
140 | ForceParticleDecay( 5122,11,1); // Lambda_b | |
141 | ForceParticleDecay( 5132,11,1); // Xsi_b | |
142 | ForceParticleDecay( 5232,11,1); // Sigma_b | |
143 | ForceParticleDecay( 5332,11,1); // Omega_b | |
144 | break; | |
145 | case kSemiElectronic: | |
146 | ForceParticleDecay( 411,11,1); // D+/- | |
147 | ForceParticleDecay( 421,11,1); // D0 | |
148 | ForceParticleDecay( 431,11,1); // D_s | |
149 | ForceParticleDecay( 4122,11,1); // Lambda_c | |
150 | ForceParticleDecay( 4132,11,1); // Xsi_c | |
151 | ForceParticleDecay( 4232,11,1); // Sigma_c | |
152 | ForceParticleDecay( 4332,11,1); // Omega_c | |
153 | ForceParticleDecay( 511,11,1); // B0 | |
154 | ForceParticleDecay( 521,11,1); // B+/- | |
155 | ForceParticleDecay( 531,11,1); // B_s | |
156 | ForceParticleDecay( 5122,11,1); // Lambda_b | |
157 | ForceParticleDecay( 5132,11,1); // Xsi_b | |
158 | ForceParticleDecay( 5232,11,1); // Sigma_b | |
159 | ForceParticleDecay( 5332,11,1); // Omega_b | |
160 | break; | |
161 | case kDiElectron: | |
162 | ForceParticleDecay( 113,11,2); // rho | |
163 | ForceParticleDecay( 333,11,2); // phi | |
164 | ForceParticleDecay( 221,11,2); // eta | |
165 | ForceParticleDecay( 223,11,2); // omega | |
166 | ForceParticleDecay( 443,11,2); // J/Psi | |
167 | ForceParticleDecay(100443,11,2);// Psi' | |
168 | ForceParticleDecay( 553,11,2); // Upsilon | |
169 | ForceParticleDecay(100553,11,2);// Upsilon' | |
170 | ForceParticleDecay(200553,11,2);// Upsilon'' | |
171 | break; | |
172 | case kBJpsiDiMuon: | |
173 | ||
174 | products[0] = 443; | |
175 | products[1] = 100443; | |
176 | mult[0] = 1; | |
177 | mult[1] = 1; | |
178 | ||
179 | ForceParticleDecay( 511, products, mult, 2); // B0 -> J/Psi (Psi') X | |
180 | ForceParticleDecay( 521, products, mult, 2); // B+/- -> J/Psi (Psi') X | |
181 | ForceParticleDecay( 531, products, mult, 2); // B_s -> J/Psi (Psi') X | |
182 | ForceParticleDecay( 5122, products, mult, 2); // Lambda_b -> J/Psi (Psi') X | |
183 | ForceParticleDecay( 100443, 443, 1); // Psi' -> J/Psi X | |
184 | ForceParticleDecay( 443,13,2); // J/Psi -> mu+ mu- | |
185 | break; | |
186 | case kBPsiPrimeDiMuon: | |
187 | ForceParticleDecay( 511,100443,1); // B0 | |
188 | ForceParticleDecay( 521,100443,1); // B+/- | |
189 | ForceParticleDecay( 531,100443,1); // B_s | |
190 | ForceParticleDecay( 5122,100443,1); // Lambda_b | |
191 | ForceParticleDecay(100443,13,2); // Psi' | |
192 | break; | |
193 | case kBJpsiDiElectron: | |
194 | ForceParticleDecay( 511,443,1); // B0 | |
195 | ForceParticleDecay( 521,443,1); // B+/- | |
196 | ForceParticleDecay( 531,443,1); // B_s | |
197 | ForceParticleDecay( 5122,443,1); // Lambda_b | |
198 | ForceParticleDecay( 443,11,2); // J/Psi | |
199 | break; | |
200 | case kBJpsi: | |
201 | ForceParticleDecay( 511,443,1); // B0 | |
202 | ForceParticleDecay( 521,443,1); // B+/- | |
203 | ForceParticleDecay( 531,443,1); // B_s | |
204 | ForceParticleDecay( 5122,443,1); // Lambda_b | |
205 | break; | |
206 | case kBPsiPrimeDiElectron: | |
207 | ForceParticleDecay( 511,100443,1); // B0 | |
208 | ForceParticleDecay( 521,100443,1); // B+/- | |
209 | ForceParticleDecay( 531,100443,1); // B_s | |
210 | ForceParticleDecay( 5122,100443,1); // Lambda_b | |
211 | ForceParticleDecay(100443,11,2); // Psi' | |
212 | break; | |
213 | case kPiToMu: | |
214 | ForceParticleDecay(211,13,1); // pi->mu | |
215 | break; | |
216 | case kKaToMu: | |
217 | ForceParticleDecay(321,13,1); // K->mu | |
218 | break; | |
219 | case kAllMuonic: | |
220 | ForceParticleDecay(211,13,1); // pi->mu | |
221 | ForceParticleDecay(321,13,1); // K->mu | |
222 | break; | |
223 | case kWToMuon: | |
224 | ForceParticleDecay( 24, 13,1); // W -> mu | |
225 | break; | |
226 | case kWToCharm: | |
227 | ForceParticleDecay( 24, 4,1); // W -> c | |
228 | break; | |
229 | case kWToCharmToMuon: | |
230 | ForceParticleDecay( 24, 4,1); // W -> c | |
231 | ForceParticleDecay( 411,13,1); // D+/- -> mu | |
232 | ForceParticleDecay( 421,13,1); // D0 -> mu | |
233 | ForceParticleDecay( 431,13,1); // D_s -> mu | |
234 | ForceParticleDecay( 4122,13,1); // Lambda_c | |
235 | ForceParticleDecay( 4132,13,1); // Xsi_c | |
236 | ForceParticleDecay( 4232,13,1); // Sigma_c | |
237 | ForceParticleDecay( 4332,13,1); // Omega_c | |
238 | break; | |
239 | case kZDiMuon: | |
240 | ForceParticleDecay( 23, 13,2); // Z -> mu+ mu- | |
241 | break; | |
242 | case kZDiElectron: | |
243 | ForceParticleDecay( 23, 11,2); // Z -> e+ e- | |
244 | break; | |
245 | case kHadronicD: | |
246 | ForceHadronicD(1); | |
247 | break; | |
248 | case kHadronicDWithout4Bodies: | |
249 | ForceHadronicD(0); | |
250 | break; | |
251 | case kPhiKK: | |
252 | ForceParticleDecay(333,321,2); // Phi->K+K- | |
253 | break; | |
254 | case kOmega: | |
255 | // ForceOmega(); | |
256 | case kAll: | |
257 | break; | |
258 | case kNoDecay: | |
259 | TPythia8::Instance()->ReadString("HadronLevel:Decay = off"); | |
260 | break; | |
261 | case kNoDecayHeavy: | |
262 | case kNeutralPion: | |
263 | break; | |
264 | } | |
265 | } | |
266 | ||
267 | Float_t AliDecayerPythia8::GetPartialBranchingRatio(Int_t ipart) | |
268 | { | |
269 | // Get the partial branching ration for the forced decay channels | |
270 | ||
271 | Pythia8::Pythia* thePythia = TPythia8::Instance()->Pythia8(); | |
272 | Pythia8::ParticleDataTable table = thePythia->particleData; | |
273 | Pythia8::ParticleDataEntry* pd = table.particleDataPtr(ipart); | |
274 | Pythia8::DecayTable decays = pd->decay; | |
275 | ||
276 | ||
277 | Int_t nc = decays.size(); | |
278 | Float_t br = 0.; | |
279 | // | |
280 | // Loop over decay channels | |
281 | for (Int_t ic = 0; ic < nc; ic++) { | |
282 | Pythia8::DecayChannel& decCh = decays[ic]; | |
283 | for (Int_t i = 1; i <= decCh.multiplicity(); i++) { | |
284 | br += decCh.bRatio(); | |
285 | } | |
286 | } | |
287 | return (br); | |
288 | } | |
289 | ||
290 | ||
291 | Int_t AliDecayerPythia8::CountProducts(Pythia8::DecayChannel& channel , Int_t particle) | |
292 | { | |
293 | // Count decay products of a given type | |
294 | Int_t np = 0; | |
295 | for (Int_t i = 1; i <= channel.multiplicity(); i++) { | |
296 | if (TMath::Abs(channel.product(i)) == particle) np++; | |
297 | } | |
298 | return np; | |
299 | } | |
300 | ||
301 | ||
302 | ||
303 | void AliDecayerPythia8::ForceParticleDecay(Int_t particle, Int_t product, Int_t mult) | |
304 | { | |
305 | // | |
306 | // Force decay of particle into products with multiplicity mult | |
307 | ||
308 | Pythia8::Pythia* thePythia = TPythia8::Instance()->Pythia8(); | |
309 | Pythia8::ParticleDataTable table = thePythia->particleData; | |
310 | Pythia8::ParticleDataEntry* pd = table.particleDataPtr(particle); | |
311 | pd->setMayDecay(true); | |
312 | Pythia8::DecayTable decays = pd->decay; | |
313 | ||
314 | ||
315 | Int_t nc = decays.size(); | |
316 | // | |
317 | // Loop over decay channels | |
318 | for (Int_t ic = 0; ic < nc; ic++) { | |
319 | Pythia8::DecayChannel& decCh = decays[ic]; | |
320 | if (CountProducts(decCh, product) >= mult) { | |
321 | decCh.onMode(1); | |
322 | } else { | |
323 | decCh.onMode(0); | |
324 | } | |
325 | } | |
326 | } | |
327 | ||
328 | void AliDecayerPythia8::ForceParticleDecay(Int_t particle, Int_t* products, Int_t* mult, Int_t npart) | |
329 | { | |
330 | // | |
331 | // Force decay of particle into products with multiplicity mult | |
332 | ||
333 | Pythia8::Pythia* thePythia = TPythia8::Instance()->Pythia8(); | |
334 | Pythia8::ParticleDataTable table = thePythia->particleData; | |
335 | Pythia8::ParticleDataEntry* pd = table.particleDataPtr(particle); | |
336 | pd->setMayDecay(true); | |
337 | Pythia8::DecayTable decays = pd->decay; | |
338 | ||
339 | Int_t nc = decays.size(); | |
340 | // | |
341 | // Loop over decay channels | |
342 | for (Int_t ic = 0; ic < nc; ic++) { | |
343 | Int_t nprod = 0; | |
344 | Pythia8::DecayChannel& decCh = decays[ic]; | |
345 | ||
346 | for (Int_t i = 0; i < npart; i++) { | |
347 | nprod += (CountProducts(decCh, products[i]) >= mult[i]); | |
348 | } | |
349 | ||
350 | if (nprod) { | |
351 | decCh.onMode(1); | |
352 | } else { | |
353 | decCh.onMode(0); | |
354 | } | |
355 | } | |
356 | } | |
357 | ||
358 | ||
359 | Float_t AliDecayerPythia8::GetLifetime(Int_t kf) | |
360 | { | |
361 | // Return lifetime of particle | |
362 | Pythia8::Pythia* thePythia = TPythia8::Instance()->Pythia8(); | |
363 | Pythia8::ParticleDataTable table = thePythia->particleData; | |
364 | Float_t tau = table.tau0(kf); | |
365 | return ( tau); | |
366 | } | |
367 | ||
368 | void AliDecayerPythia8::SwitchOffHeavyFlavour() | |
369 | { | |
370 | // Switch off heavy flavour production | |
371 | // | |
372 | // Maximum number of quark flavours used in pdf | |
373 | TPythia8::Instance()->ReadString("PDFinProcess:nQuarkIn = 3"); | |
374 | // Maximum number of flavors that can be used in showers | |
375 | TPythia8::Instance()->ReadString("SpaceShower:nQuarkIn = 3"); | |
376 | TPythia8::Instance()->ReadString("TimeShower:nGammaToQuark = 3"); | |
377 | TPythia8::Instance()->ReadString("TimeShower:nGluonToQuark = 3"); | |
378 | } | |
379 | ||
380 | ||
381 | void AliDecayerPythia8::ForceHadronicD(Int_t optUse4Bodies) | |
382 | { | |
383 | // | |
384 | // Force golden D decay modes | |
385 | // | |
386 | const Int_t kNHadrons = 5; | |
387 | Int_t hadron[kNHadrons] = {411, 421, 431, 4112, 4122}; | |
388 | ||
389 | // for D+ -> K0* (-> K- pi+) pi+ | |
390 | Int_t iKstar0 = 313; | |
391 | Int_t iKstarbar0 = -313; | |
392 | Int_t products[2] = {kKPlus, kPiMinus}, mult[2] = {1, 1}; | |
393 | ForceParticleDecay(iKstar0, products, mult, 2); | |
394 | // for Ds -> Phi pi+ | |
395 | Int_t iPhi = 333; | |
396 | ForceParticleDecay(iPhi, kKPlus, 2); // Phi->K+K- | |
397 | // for D0 -> rho0 pi+ k- | |
398 | Int_t iRho0=113; | |
399 | ForceParticleDecay(iRho0, kPiPlus, 2); // Rho0->pi+pi- | |
400 | // for Lambda_c -> Delta++ K- | |
401 | Int_t iDeltaPP = 2224; | |
402 | Int_t productsD[2] = {kProton, kPiPlus}, multD[2] = {1, 1}; | |
403 | ForceParticleDecay(iDeltaPP, productsD, multD, 2); | |
404 | ||
405 | ||
406 | Int_t decayP1[kNHadrons][4] = | |
407 | { | |
408 | {kKMinus, kPiPlus, kPiPlus, 0}, | |
409 | {kKMinus, kPiPlus, 0 , 0}, | |
410 | {kKPlus , iKstarbar0, 0 , 0}, | |
411 | {-1 , -1 , -1 , -1}, | |
412 | {kProton, iKstarbar0, 0 , 0} | |
413 | }; | |
414 | Int_t decayP2[kNHadrons][4] = | |
415 | { | |
416 | {iKstarbar0, kPiPlus, 0 , 0}, | |
417 | {kKMinus , kPiPlus, kPiPlus, kPiMinus}, | |
418 | {iPhi , kPiPlus, 0 , 0}, | |
419 | {-1 , -1 , -1 , -1}, | |
420 | {iDeltaPP , kKMinus, 0 , 0} | |
421 | }; | |
422 | Int_t decayP3[kNHadrons][4] = | |
423 | { | |
424 | {-1 , -1 , -1 , -1}, | |
425 | {kKMinus , kPiPlus, iRho0 , 0 }, | |
426 | {-1 , -1 , -1 , -1}, | |
427 | {-1 , -1 , -1 , -1}, | |
428 | {kProton , kKMinus, kPiPlus , 0} | |
429 | }; | |
430 | if(optUse4Bodies==0){ | |
431 | for(Int_t iDau=0;iDau<4;iDau++){ | |
432 | decayP2[1][iDau]=-1; | |
433 | decayP3[1][iDau]=-1; | |
434 | } | |
435 | } | |
436 | ||
437 | ||
438 | Pythia8::Pythia* thePythia = TPythia8::Instance()->Pythia8(); | |
439 | Pythia8::ParticleDataTable table = thePythia->particleData; | |
440 | ||
441 | for (Int_t ihadron = 0; ihadron < kNHadrons; ihadron++) | |
442 | { | |
443 | Pythia8::ParticleDataEntry* pd = table.particleDataPtr(hadron[ihadron]); | |
444 | pd->setMayDecay(true); | |
445 | Pythia8::DecayTable decays = pd->decay; | |
446 | ||
447 | ||
448 | for (Int_t ic = 0; ic < decays.size(); ic++) { | |
449 | Pythia8::DecayChannel& decCh = decays[ic]; | |
450 | if (( | |
451 | decCh.product(0) == decayP1[ihadron][0] && | |
452 | decCh.product(1) == decayP1[ihadron][1] && | |
453 | decCh.product(2) == decayP1[ihadron][2] && | |
454 | decCh.product(3) == decayP1[ihadron][3] && | |
455 | decCh.product(4) == 0 | |
456 | ) | |
457 | || ( | |
458 | decCh.product(0) == decayP2[ihadron][0] && | |
459 | decCh.product(1) == decayP2[ihadron][1] && | |
460 | decCh.product(2) == decayP2[ihadron][2] && | |
461 | decCh.product(3) == decayP2[ihadron][3] && | |
462 | decCh.product(4) == 0 | |
463 | ) | |
464 | || ( | |
465 | decCh.product(0) == decayP3[ihadron][0] && | |
466 | decCh.product(1) == decayP3[ihadron][1] && | |
467 | decCh.product(2) == decayP3[ihadron][2] && | |
468 | decCh.product(3) == decayP3[ihadron][3] && | |
469 | decCh.product(4) == 0 | |
470 | )) | |
471 | { | |
472 | decCh.onMode(1); | |
473 | } else { | |
474 | decCh.onMode(0); | |
475 | } // selected channel ? | |
476 | } // decay channels | |
477 | } // hadrons | |
478 | } | |
479 |