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 1.38 2002/05/30 14:59:12 morsch
19 Check geometrical acceptance. (G. Martinez)
21 Revision 1.37 2002/04/17 10:20:44 morsch
22 Coding Rule violations corrected.
24 Revision 1.36 2002/02/08 16:50:50 morsch
25 Add name and title in constructor.
27 Revision 1.35 2002/01/21 10:02:40 morsch
29 Abort if too high rapidity causes numerical paroblem. User has to specify
32 Revision 1.34 2001/11/27 13:13:07 morsch
33 Maximum lifetime for long-lived particles to be put on the stack is parameter.
34 It can be set via SetMaximumLifetime(..).
36 Revision 1.33 2001/10/21 18:35:56 hristov
37 Several pointers were set to zero in the default constructors to avoid memory management problems
39 Revision 1.32 2001/07/27 17:09:36 morsch
40 Use local SetTrack, KeepTrack and SetHighWaterMark methods
41 to delegate either to local stack or to stack owned by AliRun.
42 (Piotr Skowronski, A.M.)
44 Revision 1.31 2001/07/13 10:58:54 morsch
45 - Some coded moved to AliGenMC
46 - Improved handling of secondary vertices.
48 Revision 1.30 2001/06/15 07:55:04 morsch
49 Put only first generation decay products on the stack.
51 Revision 1.29 2001/03/27 10:58:41 morsch
52 Initialize decayer before generation. Important if run inside cocktail.
54 Revision 1.28 2001/03/09 13:01:41 morsch
55 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
56 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
58 Revision 1.27 2001/02/02 15:21:10 morsch
59 Set high water mark after last particle.
60 Use Vertex() method for Vertex.
62 Revision 1.26 2000/12/21 16:24:06 morsch
63 Coding convention clean-up
65 Revision 1.25 2000/11/30 07:12:50 alibrary
66 Introducing new Rndm and QA classes
68 Revision 1.24 2000/10/18 19:11:27 hristov
69 Division by zero fixed
71 Revision 1.23 2000/10/02 21:28:06 fca
72 Removal of useless dependecies via forward declarations
74 Revision 1.22 2000/09/12 14:14:55 morsch
75 Call fDecayer->ForceDecay() at the beginning of Generate().
77 Revision 1.21 2000/09/08 15:39:01 morsch
78 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
80 Revision 1.20 2000/09/06 14:35:44 morsch
81 Use AliDecayerPythia for particle decays.
83 Revision 1.19 2000/07/11 18:24:56 fca
84 Coding convention corrections + few minor bug fixes
86 Revision 1.18 2000/06/29 21:08:27 morsch
87 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
88 This allows to pass a pointer to a library directly to AliGenParam and avoids the
89 use of function pointers in Config.C.
91 Revision 1.17 2000/06/09 20:33:30 morsch
92 All coding rule violations except RS3 corrected
94 Revision 1.16 2000/05/02 07:51:31 morsch
95 - Control precision of pT sampling TF1::SetNpx(..)
96 - Correct initialisation of child-cuts in all constructors.
97 - Most coding rule violations corrected.
99 Revision 1.15 2000/04/03 15:42:12 morsch
100 Cuts on primary particles are separated from those on the decay products. Methods
101 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
103 Revision 1.14 1999/11/09 07:38:48 fca
104 Changes for compatibility with version 2.23 of ROOT
106 Revision 1.13 1999/11/04 11:30:31 fca
107 Correct the logics for SetForceDecay
109 Revision 1.12 1999/11/03 17:43:20 fca
110 New version from G.Martinez & A.Morsch
112 Revision 1.11 1999/09/29 09:24:14 fca
113 Introduction of the Copyright and cvs Log
119 // Class to generate particles from using paramtrized pT and y distributions.
120 // Distributions are obtained from pointer to object of type AliGenLib.
121 // (For example AliGenMUONlib)
122 // Decays are performed using Pythia.
123 // andreas.morsch@cern.ch
125 #include "AliGenParam.h"
126 #include "AliDecayerPythia.h"
127 #include "AliGenMUONlib.h"
129 #include <TParticle.h>
130 #include <TParticlePDG.h>
131 #include <TDatabasePDG.h>
132 #include <TLorentzVector.h>
136 ClassImp(AliGenParam)
138 //------------------------------------------------------------
142 <img src="picts/AliGenParam.gif">
146 //____________________________________________________________
147 //____________________________________________________________
148 AliGenParam::AliGenParam()
150 // Deafault constructor
157 // Set random number generator
164 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
166 // Constructor using number of particles parameterisation id and library
168 fTitle= "Particle Generator using pT and y parameterisation";
170 fPtParaFunc = Library->GetPt(param, tname);
171 fYParaFunc = Library->GetY (param, tname);
172 fIpParaFunc = Library->GetIp(param, tname);
181 // Set random number generator
185 //____________________________________________________________
187 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
189 // Constructor using parameterisation id and number of particles
192 fTitle= "Particle Generator using pT and y parameterisation";
194 AliGenLib* pLibrary = new AliGenMUONlib();
196 fPtParaFunc = pLibrary->GetPt(param, tname);
197 fYParaFunc = pLibrary->GetY (param, tname);
198 fIpParaFunc = pLibrary->GetIp(param, tname);
205 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
208 SetChildMomentumRange();
211 SetChildThetaRange();
215 AliGenParam::AliGenParam(Int_t npart, Int_t param,
216 Double_t (*PtPara) (Double_t*, Double_t*),
217 Double_t (*YPara ) (Double_t* ,Double_t*),
218 Int_t (*IpPara) (TRandom *))
222 // Gines Martinez 1/10/99
224 fTitle= "Particle Generator using pT and y parameterisation";
226 fPtParaFunc = PtPara;
228 fIpParaFunc = IpPara;
235 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
238 SetChildMomentumRange();
241 SetChildThetaRange();
246 AliGenParam::AliGenParam(const AliGenParam & Param)
252 //____________________________________________________________
253 AliGenParam::~AliGenParam()
260 //____________________________________________________________
261 void AliGenParam::Init()
265 fDecayer = new AliDecayerPythia();
268 <img src="picts/AliGenParam.gif">
272 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
273 // Set representation precision to 10 MeV
274 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
276 fPtPara->SetNpx(npx);
278 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
279 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
280 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
287 fdNdy0=fYParaFunc(&y1,&y2);
289 // Integral over generation region
290 Float_t intYS = yPara ->Integral(fYMin, fYMax);
291 Float_t intPt0 = ptPara->Integral(0,15);
292 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
293 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
294 if (fAnalog == kAnalog) {
295 fYWgt = intYS/fdNdy0;
296 fPtWgt = intPtS/intPt0;
297 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
299 fYWgt = intYS/fdNdy0;
300 fPtWgt = (fPtMax-fPtMin)/intPt0;
301 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
304 // particle decay related initialization
305 fDecayer->SetForceDecay(fForceDecay);
312 //____________________________________________________________
313 void AliGenParam::Generate()
316 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
317 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
318 // antineutrons in the the desired theta, phi and momentum windows;
319 // Gaussian smearing on the vertex is done if selected.
320 // The decay of heavy mesons is done using lujet,
321 // and the childern particle are tracked by GEANT
322 // However, light mesons are directly tracked by GEANT
323 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
326 // Reinitialize decayer
329 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
330 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
331 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
332 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
334 och[3]; // Momentum, polarisation and origin of the children particles from lujet
339 static TClonesArray *particles;
341 if(!particles) particles = new TClonesArray("TParticle",1000);
343 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
347 // Calculating vertex position per event
348 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
349 if(fVertexSmear==kPerEvent) {
351 for (j=0;j<3;j++) origin0[j]=fVertex[j];
356 // Generating fNpart particles
361 Int_t iPart = fIpParaFunc(fRandom);
362 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
363 TParticlePDG *particle = pDataBase->GetParticle(iPart);
364 Float_t am = particle->Mass();
369 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
372 ty = TMath::TanH(fYPara->GetRandom());
375 if (fAnalog == kAnalog) {
376 pt=fPtPara->GetRandom();
380 pt=fPtMin+random[1]*(fPtMax-fPtMin);
382 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
383 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
385 xmt=sqrt(pt*pt+am*am);
386 if (TMath::Abs(ty)==1.) {
389 "Division by 0: Please check you rapidity range !");
392 pl=xmt*ty/sqrt(1.-ty*ty);
393 theta=TMath::ATan2(pt,pl);
395 if(theta<fThetaMin || theta>fThetaMax) continue;
396 ptot=TMath::Sqrt(pt*pt+pl*pl);
398 if(ptot<fPMin || ptot>fPMax) continue;
400 p[0]=pt*TMath::Cos(phi);
401 p[1]=pt*TMath::Sin(phi);
403 if(fVertexSmear==kPerTrack) {
407 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
408 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
412 // Looking at fForceDecay :
413 // if fForceDecay != none Primary particle decays using
414 // AliPythia and children are tracked by GEANT
416 // if fForceDecay == none Primary particle is tracked by GEANT
417 // (In the latest, make sure that GEANT actually does all the decays you want)
420 if (fForceDecay != kNoDecay) {
421 // Using lujet to decay particle
422 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
423 TLorentzVector pmom(p[0], p[1], p[2], energy);
424 fDecayer->Decay(iPart,&pmom);
426 // select decay particles
427 Int_t np=fDecayer->ImportParticles(particles);
429 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
430 if (fGeometryAcceptance)
431 if (!CheckAcceptanceGeometry(np,particles)) continue;
433 Int_t* pFlag = new Int_t[np];
434 Int_t* pParent = new Int_t[np];
435 Int_t* pSelected = new Int_t[np];
436 Int_t* trackIt = new Int_t[np];
438 for (i=0; i<np; i++) {
445 TParticle* iparticle = (TParticle *) particles->At(0);
447 for (i = 1; i<np ; i++) {
449 iparticle = (TParticle *) particles->At(i);
450 Int_t kf = iparticle->GetPdgCode();
451 Int_t ks = iparticle->GetStatusCode();
455 ipF = iparticle->GetFirstDaughter();
456 ipL = iparticle->GetLastDaughter();
457 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
461 // flag decay products of particles with long life-time (c tau > .3 mum)
464 // TParticlePDG *particle = pDataBase->GetParticle(kf);
466 Double_t lifeTime = fDecayer->GetLifetime(kf);
467 // Double_t mass = particle->Mass();
468 // Double_t width = particle->Width();
469 if (lifeTime > (Double_t) fMaxLifeTime) {
470 ipF = iparticle->GetFirstDaughter();
471 ipL = iparticle->GetLastDaughter();
472 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
481 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
484 pc[0]=iparticle->Px();
485 pc[1]=iparticle->Py();
486 pc[2]=iparticle->Pz();
487 Bool_t childok = KinematicSelection(iparticle, 1);
498 } // if child selection
500 } // decay particle loop
501 } // if decay products
504 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
508 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
514 for (i = 1; i < np; i++) {
516 TParticle* iparticle = (TParticle *) particles->At(i);
517 Int_t kf = iparticle->GetPdgCode();
518 Int_t ipa = iparticle->GetFirstMother()-1;
520 och[0] = origin0[0]+iparticle->Vx()/10;
521 och[1] = origin0[1]+iparticle->Vy()/10;
522 och[2] = origin0[2]+iparticle->Vz()/10;
523 pc[0] = iparticle->Px();
524 pc[1] = iparticle->Py();
525 pc[2] = iparticle->Pz();
528 iparent = pParent[ipa];
533 SetTrack(fTrackIt*trackIt[i], iparent, kf,
535 0, kPDecay, nt, wgtch);
542 if (pFlag) delete[] pFlag;
543 if (pParent) delete[] pParent;
544 if (pSelected) delete[] pSelected;
545 if (trackIt) delete[] trackIt;
546 } // kinematic selection
547 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
550 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
556 SetHighWaterMark(nt);
559 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
561 // Assignment operator