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 1.33 2001/10/21 18:35:56 hristov
19 Several pointers were set to zero in the default constructors to avoid memory management problems
21 Revision 1.32 2001/07/27 17:09:36 morsch
22 Use local SetTrack, KeepTrack and SetHighWaterMark methods
23 to delegate either to local stack or to stack owned by AliRun.
24 (Piotr Skowronski, A.M.)
26 Revision 1.31 2001/07/13 10:58:54 morsch
27 - Some coded moved to AliGenMC
28 - Improved handling of secondary vertices.
30 Revision 1.30 2001/06/15 07:55:04 morsch
31 Put only first generation decay products on the stack.
33 Revision 1.29 2001/03/27 10:58:41 morsch
34 Initialize decayer before generation. Important if run inside cocktail.
36 Revision 1.28 2001/03/09 13:01:41 morsch
37 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
38 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
40 Revision 1.27 2001/02/02 15:21:10 morsch
41 Set high water mark after last particle.
42 Use Vertex() method for Vertex.
44 Revision 1.26 2000/12/21 16:24:06 morsch
45 Coding convention clean-up
47 Revision 1.25 2000/11/30 07:12:50 alibrary
48 Introducing new Rndm and QA classes
50 Revision 1.24 2000/10/18 19:11:27 hristov
51 Division by zero fixed
53 Revision 1.23 2000/10/02 21:28:06 fca
54 Removal of useless dependecies via forward declarations
56 Revision 1.22 2000/09/12 14:14:55 morsch
57 Call fDecayer->ForceDecay() at the beginning of Generate().
59 Revision 1.21 2000/09/08 15:39:01 morsch
60 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
62 Revision 1.20 2000/09/06 14:35:44 morsch
63 Use AliDecayerPythia for particle decays.
65 Revision 1.19 2000/07/11 18:24:56 fca
66 Coding convention corrections + few minor bug fixes
68 Revision 1.18 2000/06/29 21:08:27 morsch
69 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
70 This allows to pass a pointer to a library directly to AliGenParam and avoids the
71 use of function pointers in Config.C.
73 Revision 1.17 2000/06/09 20:33:30 morsch
74 All coding rule violations except RS3 corrected
76 Revision 1.16 2000/05/02 07:51:31 morsch
77 - Control precision of pT sampling TF1::SetNpx(..)
78 - Correct initialisation of child-cuts in all constructors.
79 - Most coding rule violations corrected.
81 Revision 1.15 2000/04/03 15:42:12 morsch
82 Cuts on primary particles are separated from those on the decay products. Methods
83 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
85 Revision 1.14 1999/11/09 07:38:48 fca
86 Changes for compatibility with version 2.23 of ROOT
88 Revision 1.13 1999/11/04 11:30:31 fca
89 Correct the logics for SetForceDecay
91 Revision 1.12 1999/11/03 17:43:20 fca
92 New version from G.Martinez & A.Morsch
94 Revision 1.11 1999/09/29 09:24:14 fca
95 Introduction of the Copyright and cvs Log
99 #include "AliGenParam.h"
100 #include "AliDecayerPythia.h"
101 #include "AliGenMUONlib.h"
103 #include <TParticle.h>
104 #include <TParticlePDG.h>
105 #include <TDatabasePDG.h>
106 #include <TLorentzVector.h>
110 ClassImp(AliGenParam)
112 //------------------------------------------------------------
116 <img src="picts/AliGenParam.gif">
120 //____________________________________________________________
121 //____________________________________________________________
122 AliGenParam::AliGenParam()
124 // Deafault constructor
131 // Set random number generator
136 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
138 // Constructor using number of particles parameterisation id and library
140 fPtParaFunc = Library->GetPt(param, tname);
141 fYParaFunc = Library->GetY (param, tname);
142 fIpParaFunc = Library->GetIp(param, tname);
151 // Set random number generator
155 //____________________________________________________________
157 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
159 // Constructor using parameterisation id and number of particles
161 AliGenLib* pLibrary = new AliGenMUONlib();
163 fPtParaFunc = pLibrary->GetPt(param, tname);
164 fYParaFunc = pLibrary->GetY (param, tname);
165 fIpParaFunc = pLibrary->GetIp(param, tname);
172 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
175 SetChildMomentumRange();
178 SetChildThetaRange();
182 AliGenParam::AliGenParam(Int_t npart, Int_t param,
183 Double_t (*PtPara) (Double_t*, Double_t*),
184 Double_t (*YPara ) (Double_t* ,Double_t*),
185 Int_t (*IpPara) (TRandom *))
189 // Gines Martinez 1/10/99
190 fPtParaFunc = PtPara;
192 fIpParaFunc = IpPara;
199 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
202 SetChildMomentumRange();
205 SetChildThetaRange();
210 AliGenParam::AliGenParam(const AliGenParam & Paramd)
215 //____________________________________________________________
216 AliGenParam::~AliGenParam()
223 //____________________________________________________________
224 void AliGenParam::Init()
228 fDecayer = new AliDecayerPythia();
231 <img src="picts/AliGenParam.gif">
235 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
236 // Set representation precision to 10 MeV
237 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
239 fPtPara->SetNpx(npx);
241 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
242 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
243 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
250 fdNdy0=fYParaFunc(&y1,&y2);
252 // Integral over generation region
253 Float_t intYS = yPara ->Integral(fYMin, fYMax);
254 Float_t intPt0 = ptPara->Integral(0,15);
255 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
256 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
257 if (fAnalog == kAnalog) {
258 fYWgt = intYS/fdNdy0;
259 fPtWgt = intPtS/intPt0;
260 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
262 fYWgt = intYS/fdNdy0;
263 fPtWgt = (fPtMax-fPtMin)/intPt0;
264 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
267 // particle decay related initialization
268 fDecayer->SetForceDecay(fForceDecay);
275 //____________________________________________________________
276 void AliGenParam::Generate()
279 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
280 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
281 // antineutrons in the the desired theta, phi and momentum windows;
282 // Gaussian smearing on the vertex is done if selected.
283 // The decay of heavy mesons is done using lujet,
284 // and the childern particle are tracked by GEANT
285 // However, light mesons are directly tracked by GEANT
286 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
289 // Reinitialize decayer
292 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
293 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
294 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
295 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
297 och[3]; // Momentum, polarisation and origin of the children particles from lujet
302 static TClonesArray *particles;
304 if(!particles) particles = new TClonesArray("TParticle",1000);
306 static TDatabasePDG *pDataBase = new TDatabasePDG();
307 if(!pDataBase) pDataBase = new TDatabasePDG();
311 // Calculating vertex position per event
312 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
313 if(fVertexSmear==kPerEvent) {
315 for (j=0;j<3;j++) origin0[j]=fVertex[j];
320 // Generating fNpart particles
325 Int_t iPart = fIpParaFunc(fRandom);
326 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
327 TParticlePDG *particle = pDataBase->GetParticle(iPart);
328 Float_t am = particle->Mass();
333 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
336 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
339 if (fAnalog == kAnalog) {
340 pt=fPtPara->GetRandom();
344 pt=fPtMin+random[1]*(fPtMax-fPtMin);
346 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
347 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
349 xmt=sqrt(pt*pt+am*am);
350 if (TMath::Abs(ty)==1.) ty=0.;
351 pl=xmt*ty/sqrt(1.-ty*ty);
352 theta=TMath::ATan2(pt,pl);
354 if(theta<fThetaMin || theta>fThetaMax) continue;
355 ptot=TMath::Sqrt(pt*pt+pl*pl);
357 if(ptot<fPMin || ptot>fPMax) continue;
359 p[0]=pt*TMath::Cos(phi);
360 p[1]=pt*TMath::Sin(phi);
362 if(fVertexSmear==kPerTrack) {
366 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
367 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
371 // Looking at fForceDecay :
372 // if fForceDecay != none Primary particle decays using
373 // AliPythia and children are tracked by GEANT
375 // if fForceDecay == none Primary particle is tracked by GEANT
376 // (In the latest, make sure that GEANT actually does all the decays you want)
379 if (fForceDecay != kNoDecay) {
380 // Using lujet to decay particle
381 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
382 TLorentzVector pmom(p[0], p[1], p[2], energy);
383 fDecayer->Decay(iPart,&pmom);
385 // select decay particles
386 Int_t np=fDecayer->ImportParticles(particles);
388 Int_t* pFlag = new Int_t[np];
389 Int_t* pParent = new Int_t[np];
390 Int_t* pSelected = new Int_t[np];
391 Int_t* trackIt = new Int_t[np];
393 for (i=0; i<np; i++) {
400 TParticle* iparticle = (TParticle *) particles->At(0);
402 for (i = 1; i<np ; i++) {
404 iparticle = (TParticle *) particles->At(i);
405 Int_t kf = iparticle->GetPdgCode();
406 Int_t ks = iparticle->GetStatusCode();
410 ipF = iparticle->GetFirstDaughter();
411 ipL = iparticle->GetLastDaughter();
412 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
416 // flag decay products of particles with long life-time (c tau > .3 mum)
419 TParticlePDG *particle = pDataBase->GetParticle(kf);
421 Double_t lifeTime = fDecayer->GetLifetime(kf);
422 Double_t mass = particle->Mass();
423 Double_t width = particle->Width();
424 if (lifeTime > (Double_t) fMaxLifeTime) {
425 ipF = iparticle->GetFirstDaughter();
426 ipL = iparticle->GetLastDaughter();
427 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
436 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
439 pc[0]=iparticle->Px();
440 pc[1]=iparticle->Py();
441 pc[2]=iparticle->Pz();
442 Bool_t childok = KinematicSelection(iparticle, 1);
453 } // if child selection
455 } // decay particle loop
456 } // if decay products
459 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
463 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
469 for (i = 1; i < np; i++) {
471 TParticle* iparticle = (TParticle *) particles->At(i);
472 Int_t kf = iparticle->GetPdgCode();
473 Int_t ipa = iparticle->GetFirstMother()-1;
475 och[0] = origin0[0]+iparticle->Vx()/10;
476 och[1] = origin0[1]+iparticle->Vy()/10;
477 och[2] = origin0[2]+iparticle->Vz()/10;
478 pc[0] = iparticle->Px();
479 pc[1] = iparticle->Py();
480 pc[2] = iparticle->Pz();
483 iparent = pParent[ipa];
487 SetTrack(fTrackIt*trackIt[i], iparent, kf,
489 0, kPDecay, nt, wgtch);
496 if (pFlag) delete[] pFlag;
497 if (pParent) delete[] pParent;
498 if (pSelected) delete[] pSelected;
499 if (trackIt) delete[] trackIt;
500 } // kinematic selection
501 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
504 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
510 SetHighWaterMark(nt);
513 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
515 // Assignment operator