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 1.35 2002/01/21 10:02:40 morsch
20 Abort if too high rapidity causes numerical paroblem. User has to specify
23 Revision 1.34 2001/11/27 13:13:07 morsch
24 Maximum lifetime for long-lived particles to be put on the stack is parameter.
25 It can be set via SetMaximumLifetime(..).
27 Revision 1.33 2001/10/21 18:35:56 hristov
28 Several pointers were set to zero in the default constructors to avoid memory management problems
30 Revision 1.32 2001/07/27 17:09:36 morsch
31 Use local SetTrack, KeepTrack and SetHighWaterMark methods
32 to delegate either to local stack or to stack owned by AliRun.
33 (Piotr Skowronski, A.M.)
35 Revision 1.31 2001/07/13 10:58:54 morsch
36 - Some coded moved to AliGenMC
37 - Improved handling of secondary vertices.
39 Revision 1.30 2001/06/15 07:55:04 morsch
40 Put only first generation decay products on the stack.
42 Revision 1.29 2001/03/27 10:58:41 morsch
43 Initialize decayer before generation. Important if run inside cocktail.
45 Revision 1.28 2001/03/09 13:01:41 morsch
46 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
47 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
49 Revision 1.27 2001/02/02 15:21:10 morsch
50 Set high water mark after last particle.
51 Use Vertex() method for Vertex.
53 Revision 1.26 2000/12/21 16:24:06 morsch
54 Coding convention clean-up
56 Revision 1.25 2000/11/30 07:12:50 alibrary
57 Introducing new Rndm and QA classes
59 Revision 1.24 2000/10/18 19:11:27 hristov
60 Division by zero fixed
62 Revision 1.23 2000/10/02 21:28:06 fca
63 Removal of useless dependecies via forward declarations
65 Revision 1.22 2000/09/12 14:14:55 morsch
66 Call fDecayer->ForceDecay() at the beginning of Generate().
68 Revision 1.21 2000/09/08 15:39:01 morsch
69 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
71 Revision 1.20 2000/09/06 14:35:44 morsch
72 Use AliDecayerPythia for particle decays.
74 Revision 1.19 2000/07/11 18:24:56 fca
75 Coding convention corrections + few minor bug fixes
77 Revision 1.18 2000/06/29 21:08:27 morsch
78 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
79 This allows to pass a pointer to a library directly to AliGenParam and avoids the
80 use of function pointers in Config.C.
82 Revision 1.17 2000/06/09 20:33:30 morsch
83 All coding rule violations except RS3 corrected
85 Revision 1.16 2000/05/02 07:51:31 morsch
86 - Control precision of pT sampling TF1::SetNpx(..)
87 - Correct initialisation of child-cuts in all constructors.
88 - Most coding rule violations corrected.
90 Revision 1.15 2000/04/03 15:42:12 morsch
91 Cuts on primary particles are separated from those on the decay products. Methods
92 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
94 Revision 1.14 1999/11/09 07:38:48 fca
95 Changes for compatibility with version 2.23 of ROOT
97 Revision 1.13 1999/11/04 11:30:31 fca
98 Correct the logics for SetForceDecay
100 Revision 1.12 1999/11/03 17:43:20 fca
101 New version from G.Martinez & A.Morsch
103 Revision 1.11 1999/09/29 09:24:14 fca
104 Introduction of the Copyright and cvs Log
108 #include "AliGenParam.h"
109 #include "AliDecayerPythia.h"
110 #include "AliGenMUONlib.h"
112 #include <TParticle.h>
113 #include <TParticlePDG.h>
114 #include <TDatabasePDG.h>
115 #include <TLorentzVector.h>
119 ClassImp(AliGenParam)
121 //------------------------------------------------------------
125 <img src="picts/AliGenParam.gif">
129 //____________________________________________________________
130 //____________________________________________________________
131 AliGenParam::AliGenParam()
133 // Deafault constructor
140 // Set random number generator
147 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
149 // Constructor using number of particles parameterisation id and library
151 fTitle= "Particle Generator using pT and y parameterisation";
153 fPtParaFunc = Library->GetPt(param, tname);
154 fYParaFunc = Library->GetY (param, tname);
155 fIpParaFunc = Library->GetIp(param, tname);
164 // Set random number generator
168 //____________________________________________________________
170 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
172 // Constructor using parameterisation id and number of particles
175 fTitle= "Particle Generator using pT and y parameterisation";
177 AliGenLib* pLibrary = new AliGenMUONlib();
179 fPtParaFunc = pLibrary->GetPt(param, tname);
180 fYParaFunc = pLibrary->GetY (param, tname);
181 fIpParaFunc = pLibrary->GetIp(param, tname);
188 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
191 SetChildMomentumRange();
194 SetChildThetaRange();
198 AliGenParam::AliGenParam(Int_t npart, Int_t param,
199 Double_t (*PtPara) (Double_t*, Double_t*),
200 Double_t (*YPara ) (Double_t* ,Double_t*),
201 Int_t (*IpPara) (TRandom *))
205 // Gines Martinez 1/10/99
207 fTitle= "Particle Generator using pT and y parameterisation";
209 fPtParaFunc = PtPara;
211 fIpParaFunc = IpPara;
218 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
221 SetChildMomentumRange();
224 SetChildThetaRange();
229 AliGenParam::AliGenParam(const AliGenParam & Paramd)
234 //____________________________________________________________
235 AliGenParam::~AliGenParam()
242 //____________________________________________________________
243 void AliGenParam::Init()
247 fDecayer = new AliDecayerPythia();
250 <img src="picts/AliGenParam.gif">
254 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
255 // Set representation precision to 10 MeV
256 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
258 fPtPara->SetNpx(npx);
260 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
261 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
262 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
269 fdNdy0=fYParaFunc(&y1,&y2);
271 // Integral over generation region
272 Float_t intYS = yPara ->Integral(fYMin, fYMax);
273 Float_t intPt0 = ptPara->Integral(0,15);
274 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
275 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
276 if (fAnalog == kAnalog) {
277 fYWgt = intYS/fdNdy0;
278 fPtWgt = intPtS/intPt0;
279 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
281 fYWgt = intYS/fdNdy0;
282 fPtWgt = (fPtMax-fPtMin)/intPt0;
283 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
286 // particle decay related initialization
287 fDecayer->SetForceDecay(fForceDecay);
294 //____________________________________________________________
295 void AliGenParam::Generate()
298 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
299 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
300 // antineutrons in the the desired theta, phi and momentum windows;
301 // Gaussian smearing on the vertex is done if selected.
302 // The decay of heavy mesons is done using lujet,
303 // and the childern particle are tracked by GEANT
304 // However, light mesons are directly tracked by GEANT
305 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
308 // Reinitialize decayer
311 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
312 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
313 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
314 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
316 och[3]; // Momentum, polarisation and origin of the children particles from lujet
321 static TClonesArray *particles;
323 if(!particles) particles = new TClonesArray("TParticle",1000);
325 static TDatabasePDG *pDataBase = new TDatabasePDG();
326 if(!pDataBase) pDataBase = new TDatabasePDG();
330 // Calculating vertex position per event
331 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
332 if(fVertexSmear==kPerEvent) {
334 for (j=0;j<3;j++) origin0[j]=fVertex[j];
339 // Generating fNpart particles
344 Int_t iPart = fIpParaFunc(fRandom);
345 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
346 TParticlePDG *particle = pDataBase->GetParticle(iPart);
347 Float_t am = particle->Mass();
352 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
355 ty = TMath::TanH(fYPara->GetRandom());
358 if (fAnalog == kAnalog) {
359 pt=fPtPara->GetRandom();
363 pt=fPtMin+random[1]*(fPtMax-fPtMin);
365 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
366 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
368 xmt=sqrt(pt*pt+am*am);
369 if (TMath::Abs(ty)==1.) {
372 "Division by 0: Please check you rapidity range !");
375 pl=xmt*ty/sqrt(1.-ty*ty);
376 theta=TMath::ATan2(pt,pl);
378 if(theta<fThetaMin || theta>fThetaMax) continue;
379 ptot=TMath::Sqrt(pt*pt+pl*pl);
381 if(ptot<fPMin || ptot>fPMax) continue;
383 p[0]=pt*TMath::Cos(phi);
384 p[1]=pt*TMath::Sin(phi);
386 if(fVertexSmear==kPerTrack) {
390 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
391 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
395 // Looking at fForceDecay :
396 // if fForceDecay != none Primary particle decays using
397 // AliPythia and children are tracked by GEANT
399 // if fForceDecay == none Primary particle is tracked by GEANT
400 // (In the latest, make sure that GEANT actually does all the decays you want)
403 if (fForceDecay != kNoDecay) {
404 // Using lujet to decay particle
405 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
406 TLorentzVector pmom(p[0], p[1], p[2], energy);
407 fDecayer->Decay(iPart,&pmom);
409 // select decay particles
410 Int_t np=fDecayer->ImportParticles(particles);
412 Int_t* pFlag = new Int_t[np];
413 Int_t* pParent = new Int_t[np];
414 Int_t* pSelected = new Int_t[np];
415 Int_t* trackIt = new Int_t[np];
417 for (i=0; i<np; i++) {
424 TParticle* iparticle = (TParticle *) particles->At(0);
426 for (i = 1; i<np ; i++) {
428 iparticle = (TParticle *) particles->At(i);
429 Int_t kf = iparticle->GetPdgCode();
430 Int_t ks = iparticle->GetStatusCode();
434 ipF = iparticle->GetFirstDaughter();
435 ipL = iparticle->GetLastDaughter();
436 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
440 // flag decay products of particles with long life-time (c tau > .3 mum)
443 // TParticlePDG *particle = pDataBase->GetParticle(kf);
445 Double_t lifeTime = fDecayer->GetLifetime(kf);
446 // Double_t mass = particle->Mass();
447 // Double_t width = particle->Width();
448 if (lifeTime > (Double_t) fMaxLifeTime) {
449 ipF = iparticle->GetFirstDaughter();
450 ipL = iparticle->GetLastDaughter();
451 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
460 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
463 pc[0]=iparticle->Px();
464 pc[1]=iparticle->Py();
465 pc[2]=iparticle->Pz();
466 Bool_t childok = KinematicSelection(iparticle, 1);
477 } // if child selection
479 } // decay particle loop
480 } // if decay products
483 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
487 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
493 for (i = 1; i < np; i++) {
495 TParticle* iparticle = (TParticle *) particles->At(i);
496 Int_t kf = iparticle->GetPdgCode();
497 Int_t ipa = iparticle->GetFirstMother()-1;
499 och[0] = origin0[0]+iparticle->Vx()/10;
500 och[1] = origin0[1]+iparticle->Vy()/10;
501 och[2] = origin0[2]+iparticle->Vz()/10;
502 pc[0] = iparticle->Px();
503 pc[1] = iparticle->Py();
504 pc[2] = iparticle->Pz();
507 iparent = pParent[ipa];
511 SetTrack(fTrackIt*trackIt[i], iparent, kf,
513 0, kPDecay, nt, wgtch);
520 if (pFlag) delete[] pFlag;
521 if (pParent) delete[] pParent;
522 if (pSelected) delete[] pSelected;
523 if (trackIt) delete[] trackIt;
524 } // kinematic selection
525 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
528 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
534 SetHighWaterMark(nt);
537 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
539 // Assignment operator