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