1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 Revision 1.36.6.3 2002/10/10 16:40:08 hristov
19 Updating VirtualMC to v3-09-02
21 Revision 1.39 2002/09/16 08:21:16 morsch
22 Use TDatabasePDG::Instance();
24 Revision 1.38 2002/05/30 14:59:12 morsch
25 Check geometrical acceptance. (G. Martinez)
27 Revision 1.37 2002/04/17 10:20:44 morsch
28 Coding Rule violations corrected.
30 Revision 1.36 2002/02/08 16:50:50 morsch
31 Add name and title in constructor.
33 Revision 1.35 2002/01/21 10:02:40 morsch
35 Abort if too high rapidity causes numerical paroblem. User has to specify
38 Revision 1.34 2001/11/27 13:13:07 morsch
39 Maximum lifetime for long-lived particles to be put on the stack is parameter.
40 It can be set via SetMaximumLifetime(..).
42 Revision 1.33 2001/10/21 18:35:56 hristov
43 Several pointers were set to zero in the default constructors to avoid memory management problems
45 Revision 1.32 2001/07/27 17:09:36 morsch
46 Use local SetTrack, KeepTrack and SetHighWaterMark methods
47 to delegate either to local stack or to stack owned by AliRun.
48 (Piotr Skowronski, A.M.)
50 Revision 1.31 2001/07/13 10:58:54 morsch
51 - Some coded moved to AliGenMC
52 - Improved handling of secondary vertices.
54 Revision 1.30 2001/06/15 07:55:04 morsch
55 Put only first generation decay products on the stack.
57 Revision 1.29 2001/03/27 10:58:41 morsch
58 Initialize decayer before generation. Important if run inside cocktail.
60 Revision 1.28 2001/03/09 13:01:41 morsch
61 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
62 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
64 Revision 1.27 2001/02/02 15:21:10 morsch
65 Set high water mark after last particle.
66 Use Vertex() method for Vertex.
68 Revision 1.26 2000/12/21 16:24:06 morsch
69 Coding convention clean-up
71 Revision 1.25 2000/11/30 07:12:50 alibrary
72 Introducing new Rndm and QA classes
74 Revision 1.24 2000/10/18 19:11:27 hristov
75 Division by zero fixed
77 Revision 1.23 2000/10/02 21:28:06 fca
78 Removal of useless dependecies via forward declarations
80 Revision 1.22 2000/09/12 14:14:55 morsch
81 Call fDecayer->ForceDecay() at the beginning of Generate().
83 Revision 1.21 2000/09/08 15:39:01 morsch
84 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
86 Revision 1.20 2000/09/06 14:35:44 morsch
87 Use AliDecayerPythia for particle decays.
89 Revision 1.19 2000/07/11 18:24:56 fca
90 Coding convention corrections + few minor bug fixes
92 Revision 1.18 2000/06/29 21:08:27 morsch
93 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
94 This allows to pass a pointer to a library directly to AliGenParam and avoids the
95 use of function pointers in Config.C.
97 Revision 1.17 2000/06/09 20:33:30 morsch
98 All coding rule violations except RS3 corrected
100 Revision 1.16 2000/05/02 07:51:31 morsch
101 - Control precision of pT sampling TF1::SetNpx(..)
102 - Correct initialisation of child-cuts in all constructors.
103 - Most coding rule violations corrected.
105 Revision 1.15 2000/04/03 15:42:12 morsch
106 Cuts on primary particles are separated from those on the decay products. Methods
107 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
109 Revision 1.14 1999/11/09 07:38:48 fca
110 Changes for compatibility with version 2.23 of ROOT
112 Revision 1.13 1999/11/04 11:30:31 fca
113 Correct the logics for SetForceDecay
115 Revision 1.12 1999/11/03 17:43:20 fca
116 New version from G.Martinez & A.Morsch
118 Revision 1.11 1999/09/29 09:24:14 fca
119 Introduction of the Copyright and cvs Log
125 // Class to generate particles from using paramtrized pT and y distributions.
126 // Distributions are obtained from pointer to object of type AliGenLib.
127 // (For example AliGenMUONlib)
128 // Decays are performed using Pythia.
129 // andreas.morsch@cern.ch
131 #include "AliGenParam.h"
132 #include "AliDecayerPythia.h"
133 #include "AliGenMUONlib.h"
135 #include <TParticle.h>
136 #include <TParticlePDG.h>
137 #include <TDatabasePDG.h>
138 #include <TLorentzVector.h>
142 ClassImp(AliGenParam)
144 //------------------------------------------------------------
148 <img src="picts/AliGenParam.gif">
152 //____________________________________________________________
153 //____________________________________________________________
154 AliGenParam::AliGenParam()
156 // Deafault constructor
163 // Set random number generator
170 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
172 // Constructor using number of particles parameterisation id and library
174 fTitle= "Particle Generator using pT and y parameterisation";
176 fPtParaFunc = Library->GetPt(param, tname);
177 fYParaFunc = Library->GetY (param, tname);
178 fIpParaFunc = Library->GetIp(param, tname);
187 // Set random number generator
191 //____________________________________________________________
193 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
195 // Constructor using parameterisation id and number of particles
198 fTitle= "Particle Generator using pT and y parameterisation";
200 AliGenLib* pLibrary = new AliGenMUONlib();
202 fPtParaFunc = pLibrary->GetPt(param, tname);
203 fYParaFunc = pLibrary->GetY (param, tname);
204 fIpParaFunc = pLibrary->GetIp(param, tname);
211 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
214 SetChildMomentumRange();
217 SetChildThetaRange();
221 AliGenParam::AliGenParam(Int_t npart, Int_t param,
222 Double_t (*PtPara) (Double_t*, Double_t*),
223 Double_t (*YPara ) (Double_t* ,Double_t*),
224 Int_t (*IpPara) (TRandom *))
228 // Gines Martinez 1/10/99
230 fTitle= "Particle Generator using pT and y parameterisation";
232 fPtParaFunc = PtPara;
234 fIpParaFunc = IpPara;
241 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
244 SetChildMomentumRange();
247 SetChildThetaRange();
252 AliGenParam::AliGenParam(const AliGenParam & Param)
258 //____________________________________________________________
259 AliGenParam::~AliGenParam()
266 //____________________________________________________________
267 void AliGenParam::Init()
271 fDecayer = new AliDecayerPythia();
274 <img src="picts/AliGenParam.gif">
278 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
279 // Set representation precision to 10 MeV
280 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
282 fPtPara->SetNpx(npx);
284 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
285 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
286 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
293 fdNdy0=fYParaFunc(&y1,&y2);
295 // Integral over generation region
296 Float_t intYS = yPara ->Integral(fYMin, fYMax);
297 Float_t intPt0 = ptPara->Integral(0,15);
298 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
299 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
300 if (fAnalog == kAnalog) {
301 fYWgt = intYS/fdNdy0;
302 fPtWgt = intPtS/intPt0;
303 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
305 fYWgt = intYS/fdNdy0;
306 fPtWgt = (fPtMax-fPtMin)/intPt0;
307 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
310 // particle decay related initialization
311 fDecayer->SetForceDecay(fForceDecay);
318 //____________________________________________________________
319 void AliGenParam::Generate()
322 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
323 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
324 // antineutrons in the the desired theta, phi and momentum windows;
325 // Gaussian smearing on the vertex is done if selected.
326 // The decay of heavy mesons is done using lujet,
327 // and the childern particle are tracked by GEANT
328 // However, light mesons are directly tracked by GEANT
329 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
332 // Reinitialize decayer
335 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
336 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
337 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
338 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
340 och[3]; // Momentum, polarisation and origin of the children particles from lujet
345 static TClonesArray *particles;
347 if(!particles) particles = new TClonesArray("TParticle",1000);
349 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
353 // Calculating vertex position per event
354 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
355 if(fVertexSmear==kPerEvent) {
357 for (j=0;j<3;j++) origin0[j]=fVertex[j];
362 // Generating fNpart particles
367 Int_t iPart = fIpParaFunc(fRandom);
368 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
369 TParticlePDG *particle = pDataBase->GetParticle(iPart);
370 Float_t am = particle->Mass();
375 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
378 ty = TMath::TanH(fYPara->GetRandom());
381 if (fAnalog == kAnalog) {
382 pt=fPtPara->GetRandom();
386 pt=fPtMin+random[1]*(fPtMax-fPtMin);
388 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
389 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
391 xmt=sqrt(pt*pt+am*am);
392 if (TMath::Abs(ty)==1.) {
395 "Division by 0: Please check you rapidity range !");
398 pl=xmt*ty/sqrt(1.-ty*ty);
399 theta=TMath::ATan2(pt,pl);
401 if(theta<fThetaMin || theta>fThetaMax) continue;
402 ptot=TMath::Sqrt(pt*pt+pl*pl);
404 if(ptot<fPMin || ptot>fPMax) continue;
406 p[0]=pt*TMath::Cos(phi);
407 p[1]=pt*TMath::Sin(phi);
409 if(fVertexSmear==kPerTrack) {
413 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
414 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
418 // Looking at fForceDecay :
419 // if fForceDecay != none Primary particle decays using
420 // AliPythia and children are tracked by GEANT
422 // if fForceDecay == none Primary particle is tracked by GEANT
423 // (In the latest, make sure that GEANT actually does all the decays you want)
426 if (fForceDecay != kNoDecay) {
427 // Using lujet to decay particle
428 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
429 TLorentzVector pmom(p[0], p[1], p[2], energy);
430 fDecayer->Decay(iPart,&pmom);
432 // select decay particles
433 Int_t np=fDecayer->ImportParticles(particles);
435 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
436 if (fGeometryAcceptance)
437 if (!CheckAcceptanceGeometry(np,particles)) continue;
439 Int_t* pFlag = new Int_t[np];
440 Int_t* pParent = new Int_t[np];
441 Int_t* pSelected = new Int_t[np];
442 Int_t* trackIt = new Int_t[np];
444 for (i=0; i<np; i++) {
451 TParticle* iparticle = (TParticle *) particles->At(0);
453 for (i = 1; i<np ; i++) {
455 iparticle = (TParticle *) particles->At(i);
456 Int_t kf = iparticle->GetPdgCode();
457 Int_t ks = iparticle->GetStatusCode();
461 ipF = iparticle->GetFirstDaughter();
462 ipL = iparticle->GetLastDaughter();
463 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
467 // flag decay products of particles with long life-time (c tau > .3 mum)
470 // TParticlePDG *particle = pDataBase->GetParticle(kf);
472 Double_t lifeTime = fDecayer->GetLifetime(kf);
473 // Double_t mass = particle->Mass();
474 // Double_t width = particle->Width();
475 if (lifeTime > (Double_t) fMaxLifeTime) {
476 ipF = iparticle->GetFirstDaughter();
477 ipL = iparticle->GetLastDaughter();
478 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
487 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
490 pc[0]=iparticle->Px();
491 pc[1]=iparticle->Py();
492 pc[2]=iparticle->Pz();
493 Bool_t childok = KinematicSelection(iparticle, 1);
504 } // if child selection
506 } // decay particle loop
507 } // if decay products
510 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
514 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
520 for (i = 1; i < np; i++) {
522 TParticle* iparticle = (TParticle *) particles->At(i);
523 Int_t kf = iparticle->GetPdgCode();
524 Int_t ipa = iparticle->GetFirstMother()-1;
526 och[0] = origin0[0]+iparticle->Vx()/10;
527 och[1] = origin0[1]+iparticle->Vy()/10;
528 och[2] = origin0[2]+iparticle->Vz()/10;
529 pc[0] = iparticle->Px();
530 pc[1] = iparticle->Py();
531 pc[2] = iparticle->Pz();
534 iparent = pParent[ipa];
539 SetTrack(fTrackIt*trackIt[i], iparent, kf,
541 0, kPDecay, nt, wgtch);
548 if (pFlag) delete[] pFlag;
549 if (pParent) delete[] pParent;
550 if (pSelected) delete[] pSelected;
551 if (trackIt) delete[] trackIt;
552 } // kinematic selection
553 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
556 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
562 SetHighWaterMark(nt);
565 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
567 // Assignment operator