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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 | // Class to generate particles from using paramtrized pT and y distributions. | |
19 | // Distributions are obtained from pointer to object of type AliGenLib. | |
20 | // (For example AliGenMUONlib) | |
21 | // Decays are performed using Pythia. | |
22 | // andreas.morsch@cern.ch | |
23 | ||
24 | #include <TCanvas.h> | |
25 | #include <TClonesArray.h> | |
26 | #include <TDatabasePDG.h> | |
27 | #include <TF1.h> | |
28 | #include <TH1F.h> | |
29 | #include <TLorentzVector.h> | |
30 | #include <TMath.h> | |
31 | #include <TParticle.h> | |
32 | #include <TParticlePDG.h> | |
33 | #include <TROOT.h> | |
34 | #include <TVirtualMC.h> | |
35 | ||
36 | #include "AliDecayer.h" | |
37 | #include "AliGenMUONlib.h" | |
38 | #include "AliGenParam.h" | |
39 | #include "AliMC.h" | |
40 | #include "AliRun.h" | |
41 | #include "AliGenEventHeader.h" | |
42 | ||
43 | ClassImp(AliGenParam) | |
44 | ||
45 | //------------------------------------------------------------ | |
46 | ||
47 | //Begin_Html | |
48 | /* | |
49 | <img src="picts/AliGenParam.gif"> | |
50 | */ | |
51 | //End_Html | |
52 | ||
53 | //____________________________________________________________ | |
54 | AliGenParam::AliGenParam(): | |
55 | fPtParaFunc(0), | |
56 | fYParaFunc(0), | |
57 | fIpParaFunc(0), | |
58 | fPtPara(0), | |
59 | fYPara(0), | |
60 | fParam(0), | |
61 | fdNdy0(0.), | |
62 | fYWgt(0.), | |
63 | fPtWgt(0.), | |
64 | fBias(0.), | |
65 | fTrials(0), | |
66 | fDeltaPt(0.01), | |
67 | fDecayer(0) | |
68 | { | |
69 | // Default constructor | |
70 | } | |
71 | //____________________________________________________________ | |
72 | AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname) | |
73 | :AliGenMC(npart), | |
74 | fPtParaFunc(Library->GetPt(param, tname)), | |
75 | fYParaFunc (Library->GetY (param, tname)), | |
76 | fIpParaFunc(Library->GetIp(param, tname)), | |
77 | fPtPara(0), | |
78 | fYPara(0), | |
79 | fParam(param), | |
80 | fdNdy0(0.), | |
81 | fYWgt(0.), | |
82 | fPtWgt(0.), | |
83 | fBias(0.), | |
84 | fTrials(0), | |
85 | fDeltaPt(0.01), | |
86 | fDecayer(0) | |
87 | { | |
88 | // Constructor using number of particles parameterisation id and library | |
89 | fName = "Param"; | |
90 | fTitle= "Particle Generator using pT and y parameterisation"; | |
91 | fAnalog = kAnalog; | |
92 | SetForceDecay(); | |
93 | } | |
94 | //____________________________________________________________ | |
95 | AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char* name): | |
96 | AliGenMC(npart), | |
97 | fPtParaFunc(0), | |
98 | fYParaFunc (0), | |
99 | fIpParaFunc(0), | |
100 | fPtPara(0), | |
101 | fYPara(0), | |
102 | fParam(param), | |
103 | fdNdy0(0.), | |
104 | fYWgt(0.), | |
105 | fPtWgt(0.), | |
106 | fBias(0.), | |
107 | fTrials(0), | |
108 | fDeltaPt(0.01), | |
109 | fDecayer(0) | |
110 | { | |
111 | // Constructor using parameterisation id and number of particles | |
112 | // | |
113 | fName = name; | |
114 | fTitle= "Particle Generator using pT and y parameterisation"; | |
115 | ||
116 | AliGenLib* pLibrary = new AliGenMUONlib(); | |
117 | fPtParaFunc = pLibrary->GetPt(param, tname); | |
118 | fYParaFunc = pLibrary->GetY (param, tname); | |
119 | fIpParaFunc = pLibrary->GetIp(param, tname); | |
120 | ||
121 | fAnalog = kAnalog; | |
122 | fChildSelect.Set(5); | |
123 | for (Int_t i=0; i<5; i++) fChildSelect[i]=0; | |
124 | SetForceDecay(); | |
125 | SetCutOnChild(); | |
126 | SetChildMomentumRange(); | |
127 | SetChildPtRange(); | |
128 | SetChildPhiRange(); | |
129 | SetChildThetaRange(); | |
130 | } | |
131 | //____________________________________________________________ | |
132 | ||
133 | AliGenParam::AliGenParam(Int_t npart, Int_t param, | |
134 | Double_t (*PtPara) (Double_t*, Double_t*), | |
135 | Double_t (*YPara ) (Double_t* ,Double_t*), | |
136 | Int_t (*IpPara) (TRandom *)) | |
137 | :AliGenMC(npart), | |
138 | ||
139 | fPtParaFunc(PtPara), | |
140 | fYParaFunc(YPara), | |
141 | fIpParaFunc(IpPara), | |
142 | fPtPara(0), | |
143 | fYPara(0), | |
144 | fParam(param), | |
145 | fdNdy0(0.), | |
146 | fYWgt(0.), | |
147 | fPtWgt(0.), | |
148 | fBias(0.), | |
149 | fTrials(0), | |
150 | fDeltaPt(0.01), | |
151 | fDecayer(0) | |
152 | { | |
153 | // Constructor | |
154 | // Gines Martinez 1/10/99 | |
155 | fName = "Param"; | |
156 | fTitle= "Particle Generator using pT and y parameterisation"; | |
157 | ||
158 | fAnalog = kAnalog; | |
159 | fChildSelect.Set(5); | |
160 | for (Int_t i=0; i<5; i++) fChildSelect[i]=0; | |
161 | SetForceDecay(); | |
162 | SetCutOnChild(); | |
163 | SetChildMomentumRange(); | |
164 | SetChildPtRange(); | |
165 | SetChildPhiRange(); | |
166 | SetChildThetaRange(); | |
167 | } | |
168 | ||
169 | //____________________________________________________________ | |
170 | AliGenParam::~AliGenParam() | |
171 | { | |
172 | // Destructor | |
173 | delete fPtPara; | |
174 | delete fYPara; | |
175 | } | |
176 | ||
177 | //____________________________________________________________ | |
178 | void AliGenParam::Init() | |
179 | { | |
180 | // Initialisation | |
181 | ||
182 | if (gMC) fDecayer = gMC->GetDecayer(); | |
183 | //Begin_Html | |
184 | /* | |
185 | <img src="picts/AliGenParam.gif"> | |
186 | */ | |
187 | //End_Html | |
188 | char name[256]; | |
189 | sprintf(name, "pt-parameterisation for %s", GetName()); | |
190 | ||
191 | if (fPtPara) fPtPara->Delete(); | |
192 | fPtPara = new TF1(name, fPtParaFunc, fPtMin, fPtMax,0); | |
193 | gROOT->GetListOfFunctions()->Remove(fPtPara); | |
194 | // Set representation precision to 10 MeV | |
195 | Int_t npx= Int_t((fPtMax - fPtMin) / fDeltaPt); | |
196 | ||
197 | fPtPara->SetNpx(npx); | |
198 | ||
199 | sprintf(name, "y-parameterisation for %s", GetName()); | |
200 | if (fYPara) fYPara->Delete(); | |
201 | fYPara = new TF1(name, fYParaFunc, fYMin, fYMax, 0); | |
202 | gROOT->GetListOfFunctions()->Remove(fYPara); | |
203 | ||
204 | ||
205 | sprintf(name, "pt-for-%s", GetName()); | |
206 | TF1 ptPara(name ,fPtParaFunc, 0, 15, 0); | |
207 | sprintf(name, "y-for-%s", GetName()); | |
208 | TF1 yPara(name, fYParaFunc, -6, 6, 0); | |
209 | ||
210 | // | |
211 | // dN/dy| y=0 | |
212 | Double_t y1=0; | |
213 | Double_t y2=0; | |
214 | ||
215 | fdNdy0=fYParaFunc(&y1,&y2); | |
216 | // | |
217 | // Integral over generation region | |
218 | Float_t intYS = yPara.Integral(fYMin, fYMax,(Double_t*) 0x0,1.e-6); | |
219 | Float_t intPt0 = ptPara.Integral(0,15,(Double_t *) 0x0,1.e-6); | |
220 | Float_t intPtS = ptPara.Integral(fPtMin,fPtMax,(Double_t*) 0x0,1.e-6); | |
221 | Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi(); | |
222 | if (fAnalog == kAnalog) { | |
223 | fYWgt = intYS/fdNdy0; | |
224 | fPtWgt = intPtS/intPt0; | |
225 | fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart; | |
226 | } else { | |
227 | fYWgt = intYS/fdNdy0; | |
228 | fPtWgt = (fPtMax-fPtMin)/intPt0; | |
229 | fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart; | |
230 | } | |
231 | // | |
232 | // particle decay related initialization | |
233 | fDecayer->SetForceDecay(fForceDecay); | |
234 | fDecayer->Init(); | |
235 | ||
236 | // | |
237 | AliGenMC::Init(); | |
238 | } | |
239 | ||
240 | //____________________________________________________________ | |
241 | void AliGenParam::Generate() | |
242 | { | |
243 | // | |
244 | // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion, | |
245 | // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and | |
246 | // antineutrons in the the desired theta, phi and momentum windows; | |
247 | // Gaussian smearing on the vertex is done if selected. | |
248 | // The decay of heavy mesons is done using lujet, | |
249 | // and the childern particle are tracked by GEANT | |
250 | // However, light mesons are directly tracked by GEANT | |
251 | // setting fForceDecay = nodecay (SetForceDecay(nodecay)) | |
252 | // | |
253 | // | |
254 | // Reinitialize decayer | |
255 | fDecayer->SetForceDecay(fForceDecay); | |
256 | fDecayer->Init(); | |
257 | ||
258 | // | |
259 | Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking) | |
260 | Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking) | |
261 | Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle | |
262 | Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum | |
263 | Float_t p[3], pc[3], | |
264 | och[3]; // Momentum, polarisation and origin of the children particles from lujet | |
265 | Double_t ty, xmt; | |
266 | Int_t nt, i, j; | |
267 | Float_t wgtp, wgtch; | |
268 | Double_t dummy; | |
269 | static TClonesArray *particles; | |
270 | // | |
271 | if(!particles) particles = new TClonesArray("TParticle",1000); | |
272 | ||
273 | TDatabasePDG *pDataBase = TDatabasePDG::Instance(); | |
274 | // | |
275 | Float_t random[6]; | |
276 | ||
277 | // Calculating vertex position per event | |
278 | for (j=0;j<3;j++) origin0[j]=fOrigin[j]; | |
279 | if(fVertexSmear==kPerEvent) { | |
280 | Vertex(); | |
281 | for (j=0;j<3;j++) origin0[j]=fVertex[j]; | |
282 | } | |
283 | ||
284 | Int_t ipa=0; | |
285 | ||
286 | // Generating fNpart particles | |
287 | fNprimaries = 0; | |
288 | ||
289 | while (ipa<fNpart) { | |
290 | while(1) { | |
291 | // | |
292 | // particle type | |
293 | Int_t iPart = fIpParaFunc(fRandom); | |
294 | fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight; | |
295 | TParticlePDG *particle = pDataBase->GetParticle(iPart); | |
296 | Float_t am = particle->Mass(); | |
297 | ||
298 | Rndm(random,2); | |
299 | // | |
300 | // phi | |
301 | phi=fPhiMin+random[0]*(fPhiMax-fPhiMin); | |
302 | // | |
303 | // y | |
304 | ty = TMath::TanH(fYPara->GetRandom()); | |
305 | // | |
306 | // pT | |
307 | if (fAnalog == kAnalog) { | |
308 | pt=fPtPara->GetRandom(); | |
309 | wgtp=fParentWeight; | |
310 | wgtch=fChildWeight; | |
311 | } else { | |
312 | pt=fPtMin+random[1]*(fPtMax-fPtMin); | |
313 | Double_t ptd=pt; | |
314 | wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy); | |
315 | wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy); | |
316 | } | |
317 | xmt=sqrt(pt*pt+am*am); | |
318 | if (TMath::Abs(ty)==1.) { | |
319 | ty=0.; | |
320 | Fatal("AliGenParam", | |
321 | "Division by 0: Please check you rapidity range !"); | |
322 | } | |
323 | ||
324 | pl=xmt*ty/sqrt(1.-ty*ty); | |
325 | theta=TMath::ATan2(pt,pl); | |
326 | // Cut on theta | |
327 | if(theta<fThetaMin || theta>fThetaMax) continue; | |
328 | ptot=TMath::Sqrt(pt*pt+pl*pl); | |
329 | // Cut on momentum | |
330 | if(ptot<fPMin || ptot>fPMax) continue; | |
331 | // | |
332 | p[0]=pt*TMath::Cos(phi); | |
333 | p[1]=pt*TMath::Sin(phi); | |
334 | p[2]=pl; | |
335 | if(fVertexSmear==kPerTrack) { | |
336 | Rndm(random,6); | |
337 | for (j=0;j<3;j++) { | |
338 | origin0[j]= | |
339 | fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* | |
340 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); | |
341 | } | |
342 | } | |
343 | ||
344 | // Looking at fForceDecay : | |
345 | // if fForceDecay != none Primary particle decays using | |
346 | // AliPythia and children are tracked by GEANT | |
347 | // | |
348 | // if fForceDecay == none Primary particle is tracked by GEANT | |
349 | // (In the latest, make sure that GEANT actually does all the decays you want) | |
350 | // | |
351 | ||
352 | if (fForceDecay != kNoDecay) { | |
353 | // Using lujet to decay particle | |
354 | Float_t energy=TMath::Sqrt(ptot*ptot+am*am); | |
355 | TLorentzVector pmom(p[0], p[1], p[2], energy); | |
356 | fDecayer->Decay(iPart,&pmom); | |
357 | // | |
358 | // select decay particles | |
359 | Int_t np=fDecayer->ImportParticles(particles); | |
360 | ||
361 | // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut; | |
362 | if (fGeometryAcceptance) | |
363 | if (!CheckAcceptanceGeometry(np,particles)) continue; | |
364 | Int_t ncsel=0; | |
365 | Int_t* pFlag = new Int_t[np]; | |
366 | Int_t* pParent = new Int_t[np]; | |
367 | Int_t* pSelected = new Int_t[np]; | |
368 | Int_t* trackIt = new Int_t[np]; | |
369 | ||
370 | for (i=0; i<np; i++) { | |
371 | pFlag[i] = 0; | |
372 | pSelected[i] = 0; | |
373 | pParent[i] = -1; | |
374 | } | |
375 | ||
376 | if (np >1) { | |
377 | TParticle* iparticle = (TParticle *) particles->At(0); | |
378 | Int_t ipF, ipL; | |
379 | for (i = 1; i<np ; i++) { | |
380 | trackIt[i] = 1; | |
381 | iparticle = (TParticle *) particles->At(i); | |
382 | Int_t kf = iparticle->GetPdgCode(); | |
383 | Int_t ks = iparticle->GetStatusCode(); | |
384 | // flagged particle | |
385 | ||
386 | if (pFlag[i] == 1) { | |
387 | ipF = iparticle->GetFirstDaughter(); | |
388 | ipL = iparticle->GetLastDaughter(); | |
389 | if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1; | |
390 | continue; | |
391 | } | |
392 | ||
393 | // flag decay products of particles with long life-time (c tau > .3 mum) | |
394 | ||
395 | if (ks != 1) { | |
396 | // TParticlePDG *particle = pDataBase->GetParticle(kf); | |
397 | ||
398 | Double_t lifeTime = fDecayer->GetLifetime(kf); | |
399 | // Double_t mass = particle->Mass(); | |
400 | // Double_t width = particle->Width(); | |
401 | if (lifeTime > (Double_t) fMaxLifeTime) { | |
402 | ipF = iparticle->GetFirstDaughter(); | |
403 | ipL = iparticle->GetLastDaughter(); | |
404 | if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1; | |
405 | } else{ | |
406 | trackIt[i] = 0; | |
407 | pSelected[i] = 1; | |
408 | } | |
409 | } // ks==1 ? | |
410 | // | |
411 | // children | |
412 | ||
413 | if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i]) | |
414 | { | |
415 | if (fCutOnChild) { | |
416 | pc[0]=iparticle->Px(); | |
417 | pc[1]=iparticle->Py(); | |
418 | pc[2]=iparticle->Pz(); | |
419 | Bool_t childok = KinematicSelection(iparticle, 1); | |
420 | if(childok) { | |
421 | pSelected[i] = 1; | |
422 | ncsel++; | |
423 | } else { | |
424 | ncsel=-1; | |
425 | break; | |
426 | } // child kine cuts | |
427 | } else { | |
428 | pSelected[i] = 1; | |
429 | ncsel++; | |
430 | } // if child selection | |
431 | } // select muon | |
432 | } // decay particle loop | |
433 | } // if decay products | |
434 | ||
435 | Int_t iparent; | |
436 | if ((fCutOnChild && ncsel >0) || !fCutOnChild){ | |
437 | ipa++; | |
438 | // | |
439 | // Parent | |
440 | PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp); | |
441 | pParent[0] = nt; | |
442 | KeepTrack(nt); | |
443 | fNprimaries++; | |
444 | ||
445 | // | |
446 | // Decay Products | |
447 | // | |
448 | for (i = 1; i < np; i++) { | |
449 | if (pSelected[i]) { | |
450 | TParticle* iparticle = (TParticle *) particles->At(i); | |
451 | Int_t kf = iparticle->GetPdgCode(); | |
452 | Int_t ipa = iparticle->GetFirstMother()-1; | |
453 | ||
454 | och[0] = origin0[0]+iparticle->Vx()/10; | |
455 | och[1] = origin0[1]+iparticle->Vy()/10; | |
456 | och[2] = origin0[2]+iparticle->Vz()/10; | |
457 | pc[0] = iparticle->Px(); | |
458 | pc[1] = iparticle->Py(); | |
459 | pc[2] = iparticle->Pz(); | |
460 | ||
461 | if (ipa > -1) { | |
462 | iparent = pParent[ipa]; | |
463 | } else { | |
464 | iparent = -1; | |
465 | } | |
466 | ||
467 | PushTrack(fTrackIt*trackIt[i], iparent, kf, | |
468 | pc, och, polar, | |
469 | 0, kPDecay, nt, wgtch); | |
470 | pParent[i] = nt; | |
471 | KeepTrack(nt); | |
472 | fNprimaries++; | |
473 | } // Selected | |
474 | } // Particle loop | |
475 | } // Decays by Lujet | |
476 | particles->Clear(); | |
477 | if (pFlag) delete[] pFlag; | |
478 | if (pParent) delete[] pParent; | |
479 | if (pSelected) delete[] pSelected; | |
480 | if (trackIt) delete[] trackIt; | |
481 | } // kinematic selection | |
482 | else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons) | |
483 | { | |
484 | gAlice->GetMCApp()-> | |
485 | PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp); | |
486 | ipa++; | |
487 | fNprimaries++; | |
488 | } | |
489 | break; | |
490 | } // while | |
491 | } // event loop | |
492 | ||
493 | SetHighWaterMark(nt); | |
494 | ||
495 | AliGenEventHeader* header = new AliGenEventHeader("PARAM"); | |
496 | header->SetPrimaryVertex(fVertex); | |
497 | header->SetNProduced(fNprimaries); | |
498 | AddHeader(header); | |
499 | } | |
500 | //____________________________________________________________________________________ | |
501 | Float_t AliGenParam::GetRelativeArea(Float_t ptMin, Float_t ptMax, Float_t yMin, Float_t yMax, Float_t phiMin, Float_t phiMax) | |
502 | { | |
503 | // | |
504 | // Normalisation for selected kinematic region | |
505 | // | |
506 | Float_t ratio = | |
507 | fPtPara->Integral(ptMin,ptMax,(Double_t *)0,1.e-6) / fPtPara->Integral( fPtPara->GetXmin(), fPtPara->GetXmax(),(Double_t *)0,1.e-6) * | |
508 | fYPara->Integral(yMin,yMax,(Double_t *)0,1.e-6)/fYPara->Integral(fYPara->GetXmin(),fYPara->GetXmax(),(Double_t *)0,1.e-6) * | |
509 | (phiMax-phiMin)/360.; | |
510 | return TMath::Abs(ratio); | |
511 | } | |
512 | ||
513 | //____________________________________________________________________________________ | |
514 | ||
515 | void AliGenParam::Draw( const char * /*opt*/) | |
516 | { | |
517 | // | |
518 | // Draw the pT and y Distributions | |
519 | // | |
520 | TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700); | |
521 | c0->Divide(2,1); | |
522 | c0->cd(1); | |
523 | fPtPara->Draw(); | |
524 | fPtPara->GetHistogram()->SetXTitle("p_{T} (GeV)"); | |
525 | c0->cd(2); | |
526 | fYPara->Draw(); | |
527 | fYPara->GetHistogram()->SetXTitle("y"); | |
528 | } | |
529 | ||
530 | ||
531 | ||
532 |