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 1.34 2001/11/27 13:13:07 morsch
19 Maximum lifetime for long-lived particles to be put on the stack is parameter.
20 It can be set via SetMaximumLifetime(..).
22 Revision 1.33 2001/10/21 18:35:56 hristov
23 Several pointers were set to zero in the default constructors to avoid memory management problems
25 Revision 1.32 2001/07/27 17:09:36 morsch
26 Use local SetTrack, KeepTrack and SetHighWaterMark methods
27 to delegate either to local stack or to stack owned by AliRun.
28 (Piotr Skowronski, A.M.)
30 Revision 1.31 2001/07/13 10:58:54 morsch
31 - Some coded moved to AliGenMC
32 - Improved handling of secondary vertices.
34 Revision 1.30 2001/06/15 07:55:04 morsch
35 Put only first generation decay products on the stack.
37 Revision 1.29 2001/03/27 10:58:41 morsch
38 Initialize decayer before generation. Important if run inside cocktail.
40 Revision 1.28 2001/03/09 13:01:41 morsch
41 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
42 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
44 Revision 1.27 2001/02/02 15:21:10 morsch
45 Set high water mark after last particle.
46 Use Vertex() method for Vertex.
48 Revision 1.26 2000/12/21 16:24:06 morsch
49 Coding convention clean-up
51 Revision 1.25 2000/11/30 07:12:50 alibrary
52 Introducing new Rndm and QA classes
54 Revision 1.24 2000/10/18 19:11:27 hristov
55 Division by zero fixed
57 Revision 1.23 2000/10/02 21:28:06 fca
58 Removal of useless dependecies via forward declarations
60 Revision 1.22 2000/09/12 14:14:55 morsch
61 Call fDecayer->ForceDecay() at the beginning of Generate().
63 Revision 1.21 2000/09/08 15:39:01 morsch
64 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
66 Revision 1.20 2000/09/06 14:35:44 morsch
67 Use AliDecayerPythia for particle decays.
69 Revision 1.19 2000/07/11 18:24:56 fca
70 Coding convention corrections + few minor bug fixes
72 Revision 1.18 2000/06/29 21:08:27 morsch
73 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
74 This allows to pass a pointer to a library directly to AliGenParam and avoids the
75 use of function pointers in Config.C.
77 Revision 1.17 2000/06/09 20:33:30 morsch
78 All coding rule violations except RS3 corrected
80 Revision 1.16 2000/05/02 07:51:31 morsch
81 - Control precision of pT sampling TF1::SetNpx(..)
82 - Correct initialisation of child-cuts in all constructors.
83 - Most coding rule violations corrected.
85 Revision 1.15 2000/04/03 15:42:12 morsch
86 Cuts on primary particles are separated from those on the decay products. Methods
87 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
89 Revision 1.14 1999/11/09 07:38:48 fca
90 Changes for compatibility with version 2.23 of ROOT
92 Revision 1.13 1999/11/04 11:30:31 fca
93 Correct the logics for SetForceDecay
95 Revision 1.12 1999/11/03 17:43:20 fca
96 New version from G.Martinez & A.Morsch
98 Revision 1.11 1999/09/29 09:24:14 fca
99 Introduction of the Copyright and cvs Log
103 #include "AliGenParam.h"
104 #include "AliDecayerPythia.h"
105 #include "AliGenMUONlib.h"
107 #include <TParticle.h>
108 #include <TParticlePDG.h>
109 #include <TDatabasePDG.h>
110 #include <TLorentzVector.h>
114 ClassImp(AliGenParam)
116 //------------------------------------------------------------
120 <img src="picts/AliGenParam.gif">
124 //____________________________________________________________
125 //____________________________________________________________
126 AliGenParam::AliGenParam()
128 // Deafault constructor
135 // Set random number generator
140 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
142 // Constructor using number of particles parameterisation id and library
144 fPtParaFunc = Library->GetPt(param, tname);
145 fYParaFunc = Library->GetY (param, tname);
146 fIpParaFunc = Library->GetIp(param, tname);
155 // Set random number generator
159 //____________________________________________________________
161 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
163 // Constructor using parameterisation id and number of particles
165 AliGenLib* pLibrary = new AliGenMUONlib();
167 fPtParaFunc = pLibrary->GetPt(param, tname);
168 fYParaFunc = pLibrary->GetY (param, tname);
169 fIpParaFunc = pLibrary->GetIp(param, tname);
176 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
179 SetChildMomentumRange();
182 SetChildThetaRange();
186 AliGenParam::AliGenParam(Int_t npart, Int_t param,
187 Double_t (*PtPara) (Double_t*, Double_t*),
188 Double_t (*YPara ) (Double_t* ,Double_t*),
189 Int_t (*IpPara) (TRandom *))
193 // Gines Martinez 1/10/99
194 fPtParaFunc = PtPara;
196 fIpParaFunc = IpPara;
203 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
206 SetChildMomentumRange();
209 SetChildThetaRange();
214 AliGenParam::AliGenParam(const AliGenParam & Paramd)
219 //____________________________________________________________
220 AliGenParam::~AliGenParam()
227 //____________________________________________________________
228 void AliGenParam::Init()
232 fDecayer = new AliDecayerPythia();
235 <img src="picts/AliGenParam.gif">
239 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
240 // Set representation precision to 10 MeV
241 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
243 fPtPara->SetNpx(npx);
245 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
246 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
247 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
254 fdNdy0=fYParaFunc(&y1,&y2);
256 // Integral over generation region
257 Float_t intYS = yPara ->Integral(fYMin, fYMax);
258 Float_t intPt0 = ptPara->Integral(0,15);
259 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
260 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
261 if (fAnalog == kAnalog) {
262 fYWgt = intYS/fdNdy0;
263 fPtWgt = intPtS/intPt0;
264 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
266 fYWgt = intYS/fdNdy0;
267 fPtWgt = (fPtMax-fPtMin)/intPt0;
268 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
271 // particle decay related initialization
272 fDecayer->SetForceDecay(fForceDecay);
279 //____________________________________________________________
280 void AliGenParam::Generate()
283 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
284 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
285 // antineutrons in the the desired theta, phi and momentum windows;
286 // Gaussian smearing on the vertex is done if selected.
287 // The decay of heavy mesons is done using lujet,
288 // and the childern particle are tracked by GEANT
289 // However, light mesons are directly tracked by GEANT
290 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
293 // Reinitialize decayer
296 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
297 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
298 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
299 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
301 och[3]; // Momentum, polarisation and origin of the children particles from lujet
306 static TClonesArray *particles;
308 if(!particles) particles = new TClonesArray("TParticle",1000);
310 static TDatabasePDG *pDataBase = new TDatabasePDG();
311 if(!pDataBase) pDataBase = new TDatabasePDG();
315 // Calculating vertex position per event
316 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
317 if(fVertexSmear==kPerEvent) {
319 for (j=0;j<3;j++) origin0[j]=fVertex[j];
324 // Generating fNpart particles
329 Int_t iPart = fIpParaFunc(fRandom);
330 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
331 TParticlePDG *particle = pDataBase->GetParticle(iPart);
332 Float_t am = particle->Mass();
337 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
340 ty = TMath::TanH(fYPara->GetRandom());
343 if (fAnalog == kAnalog) {
344 pt=fPtPara->GetRandom();
348 pt=fPtMin+random[1]*(fPtMax-fPtMin);
350 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
351 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
353 xmt=sqrt(pt*pt+am*am);
354 if (TMath::Abs(ty)==1.) {
357 "Division by 0: Please check you rapidity range !");
360 pl=xmt*ty/sqrt(1.-ty*ty);
361 theta=TMath::ATan2(pt,pl);
363 if(theta<fThetaMin || theta>fThetaMax) continue;
364 ptot=TMath::Sqrt(pt*pt+pl*pl);
366 if(ptot<fPMin || ptot>fPMax) continue;
368 p[0]=pt*TMath::Cos(phi);
369 p[1]=pt*TMath::Sin(phi);
371 if(fVertexSmear==kPerTrack) {
375 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
376 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
380 // Looking at fForceDecay :
381 // if fForceDecay != none Primary particle decays using
382 // AliPythia and children are tracked by GEANT
384 // if fForceDecay == none Primary particle is tracked by GEANT
385 // (In the latest, make sure that GEANT actually does all the decays you want)
388 if (fForceDecay != kNoDecay) {
389 // Using lujet to decay particle
390 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
391 TLorentzVector pmom(p[0], p[1], p[2], energy);
392 fDecayer->Decay(iPart,&pmom);
394 // select decay particles
395 Int_t np=fDecayer->ImportParticles(particles);
397 Int_t* pFlag = new Int_t[np];
398 Int_t* pParent = new Int_t[np];
399 Int_t* pSelected = new Int_t[np];
400 Int_t* trackIt = new Int_t[np];
402 for (i=0; i<np; i++) {
409 TParticle* iparticle = (TParticle *) particles->At(0);
411 for (i = 1; i<np ; i++) {
413 iparticle = (TParticle *) particles->At(i);
414 Int_t kf = iparticle->GetPdgCode();
415 Int_t ks = iparticle->GetStatusCode();
419 ipF = iparticle->GetFirstDaughter();
420 ipL = iparticle->GetLastDaughter();
421 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
425 // flag decay products of particles with long life-time (c tau > .3 mum)
428 // TParticlePDG *particle = pDataBase->GetParticle(kf);
430 Double_t lifeTime = fDecayer->GetLifetime(kf);
431 // Double_t mass = particle->Mass();
432 // Double_t width = particle->Width();
433 if (lifeTime > (Double_t) fMaxLifeTime) {
434 ipF = iparticle->GetFirstDaughter();
435 ipL = iparticle->GetLastDaughter();
436 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
445 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
448 pc[0]=iparticle->Px();
449 pc[1]=iparticle->Py();
450 pc[2]=iparticle->Pz();
451 Bool_t childok = KinematicSelection(iparticle, 1);
462 } // if child selection
464 } // decay particle loop
465 } // if decay products
468 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
472 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
478 for (i = 1; i < np; i++) {
480 TParticle* iparticle = (TParticle *) particles->At(i);
481 Int_t kf = iparticle->GetPdgCode();
482 Int_t ipa = iparticle->GetFirstMother()-1;
484 och[0] = origin0[0]+iparticle->Vx()/10;
485 och[1] = origin0[1]+iparticle->Vy()/10;
486 och[2] = origin0[2]+iparticle->Vz()/10;
487 pc[0] = iparticle->Px();
488 pc[1] = iparticle->Py();
489 pc[2] = iparticle->Pz();
492 iparent = pParent[ipa];
496 SetTrack(fTrackIt*trackIt[i], iparent, kf,
498 0, kPDecay, nt, wgtch);
505 if (pFlag) delete[] pFlag;
506 if (pParent) delete[] pParent;
507 if (pSelected) delete[] pSelected;
508 if (trackIt) delete[] trackIt;
509 } // kinematic selection
510 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
513 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
519 SetHighWaterMark(nt);
522 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
524 // Assignment operator