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 1.32 2001/07/27 17:09:36 morsch
19 Use local SetTrack, KeepTrack and SetHighWaterMark methods
20 to delegate either to local stack or to stack owned by AliRun.
21 (Piotr Skowronski, A.M.)
23 Revision 1.31 2001/07/13 10:58:54 morsch
24 - Some coded moved to AliGenMC
25 - Improved handling of secondary vertices.
27 Revision 1.30 2001/06/15 07:55:04 morsch
28 Put only first generation decay products on the stack.
30 Revision 1.29 2001/03/27 10:58:41 morsch
31 Initialize decayer before generation. Important if run inside cocktail.
33 Revision 1.28 2001/03/09 13:01:41 morsch
34 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
35 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
37 Revision 1.27 2001/02/02 15:21:10 morsch
38 Set high water mark after last particle.
39 Use Vertex() method for Vertex.
41 Revision 1.26 2000/12/21 16:24:06 morsch
42 Coding convention clean-up
44 Revision 1.25 2000/11/30 07:12:50 alibrary
45 Introducing new Rndm and QA classes
47 Revision 1.24 2000/10/18 19:11:27 hristov
48 Division by zero fixed
50 Revision 1.23 2000/10/02 21:28:06 fca
51 Removal of useless dependecies via forward declarations
53 Revision 1.22 2000/09/12 14:14:55 morsch
54 Call fDecayer->ForceDecay() at the beginning of Generate().
56 Revision 1.21 2000/09/08 15:39:01 morsch
57 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
59 Revision 1.20 2000/09/06 14:35:44 morsch
60 Use AliDecayerPythia for particle decays.
62 Revision 1.19 2000/07/11 18:24:56 fca
63 Coding convention corrections + few minor bug fixes
65 Revision 1.18 2000/06/29 21:08:27 morsch
66 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
67 This allows to pass a pointer to a library directly to AliGenParam and avoids the
68 use of function pointers in Config.C.
70 Revision 1.17 2000/06/09 20:33:30 morsch
71 All coding rule violations except RS3 corrected
73 Revision 1.16 2000/05/02 07:51:31 morsch
74 - Control precision of pT sampling TF1::SetNpx(..)
75 - Correct initialisation of child-cuts in all constructors.
76 - Most coding rule violations corrected.
78 Revision 1.15 2000/04/03 15:42:12 morsch
79 Cuts on primary particles are separated from those on the decay products. Methods
80 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
82 Revision 1.14 1999/11/09 07:38:48 fca
83 Changes for compatibility with version 2.23 of ROOT
85 Revision 1.13 1999/11/04 11:30:31 fca
86 Correct the logics for SetForceDecay
88 Revision 1.12 1999/11/03 17:43:20 fca
89 New version from G.Martinez & A.Morsch
91 Revision 1.11 1999/09/29 09:24:14 fca
92 Introduction of the Copyright and cvs Log
96 #include "AliGenParam.h"
97 #include "AliDecayerPythia.h"
98 #include "AliGenMUONlib.h"
100 #include <TParticle.h>
101 #include <TParticlePDG.h>
102 #include <TDatabasePDG.h>
103 #include <TLorentzVector.h>
107 ClassImp(AliGenParam)
109 //------------------------------------------------------------
113 <img src="picts/AliGenParam.gif">
117 //____________________________________________________________
118 //____________________________________________________________
119 AliGenParam::AliGenParam()
121 // Deafault constructor
128 // Set random number generator
133 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
135 // Constructor using number of particles parameterisation id and library
137 fPtParaFunc = Library->GetPt(param, tname);
138 fYParaFunc = Library->GetY (param, tname);
139 fIpParaFunc = Library->GetIp(param, tname);
148 // Set random number generator
152 //____________________________________________________________
154 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
156 // Constructor using parameterisation id and number of particles
158 AliGenLib* pLibrary = new AliGenMUONlib();
160 fPtParaFunc = pLibrary->GetPt(param, tname);
161 fYParaFunc = pLibrary->GetY (param, tname);
162 fIpParaFunc = pLibrary->GetIp(param, tname);
169 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
172 SetChildMomentumRange();
175 SetChildThetaRange();
179 AliGenParam::AliGenParam(Int_t npart, Int_t param,
180 Double_t (*PtPara) (Double_t*, Double_t*),
181 Double_t (*YPara ) (Double_t* ,Double_t*),
182 Int_t (*IpPara) (TRandom *))
186 // Gines Martinez 1/10/99
187 fPtParaFunc = PtPara;
189 fIpParaFunc = IpPara;
196 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
199 SetChildMomentumRange();
202 SetChildThetaRange();
207 AliGenParam::AliGenParam(const AliGenParam & Paramd)
212 //____________________________________________________________
213 AliGenParam::~AliGenParam()
220 //____________________________________________________________
221 void AliGenParam::Init()
225 fDecayer = new AliDecayerPythia();
228 <img src="picts/AliGenParam.gif">
232 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
233 // Set representation precision to 10 MeV
234 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
236 fPtPara->SetNpx(npx);
238 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
239 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
240 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
247 fdNdy0=fYParaFunc(&y1,&y2);
249 // Integral over generation region
250 Float_t intYS = yPara ->Integral(fYMin, fYMax);
251 Float_t intPt0 = ptPara->Integral(0,15);
252 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
253 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
254 if (fAnalog == kAnalog) {
255 fYWgt = intYS/fdNdy0;
256 fPtWgt = intPtS/intPt0;
257 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
259 fYWgt = intYS/fdNdy0;
260 fPtWgt = (fPtMax-fPtMin)/intPt0;
261 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
264 // particle decay related initialization
265 fDecayer->SetForceDecay(fForceDecay);
272 //____________________________________________________________
273 void AliGenParam::Generate()
276 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
277 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
278 // antineutrons in the the desired theta, phi and momentum windows;
279 // Gaussian smearing on the vertex is done if selected.
280 // The decay of heavy mesons is done using lujet,
281 // and the childern particle are tracked by GEANT
282 // However, light mesons are directly tracked by GEANT
283 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
286 // Reinitialize decayer
289 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
290 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
291 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
292 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
294 och[3]; // Momentum, polarisation and origin of the children particles from lujet
299 static TClonesArray *particles;
301 if(!particles) particles = new TClonesArray("TParticle",1000);
303 static TDatabasePDG *pDataBase = new TDatabasePDG();
304 if(!pDataBase) pDataBase = new TDatabasePDG();
308 // Calculating vertex position per event
309 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
310 if(fVertexSmear==kPerEvent) {
312 for (j=0;j<3;j++) origin0[j]=fVertex[j];
317 // Generating fNpart particles
322 Int_t iPart = fIpParaFunc(fRandom);
323 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
324 TParticlePDG *particle = pDataBase->GetParticle(iPart);
325 Float_t am = particle->Mass();
330 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
333 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
336 if (fAnalog == kAnalog) {
337 pt=fPtPara->GetRandom();
341 pt=fPtMin+random[1]*(fPtMax-fPtMin);
343 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
344 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
346 xmt=sqrt(pt*pt+am*am);
347 if (TMath::Abs(ty)==1) ty=0;
348 pl=xmt*ty/sqrt(1.-ty*ty);
349 theta=TMath::ATan2(pt,pl);
351 if(theta<fThetaMin || theta>fThetaMax) continue;
352 ptot=TMath::Sqrt(pt*pt+pl*pl);
354 if(ptot<fPMin || ptot>fPMax) continue;
356 p[0]=pt*TMath::Cos(phi);
357 p[1]=pt*TMath::Sin(phi);
359 if(fVertexSmear==kPerTrack) {
363 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
364 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
368 // Looking at fForceDecay :
369 // if fForceDecay != none Primary particle decays using
370 // AliPythia and children are tracked by GEANT
372 // if fForceDecay == none Primary particle is tracked by GEANT
373 // (In the latest, make sure that GEANT actually does all the decays you want)
376 if (fForceDecay != kNoDecay) {
377 // Using lujet to decay particle
378 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
379 TLorentzVector pmom(p[0], p[1], p[2], energy);
380 fDecayer->Decay(iPart,&pmom);
382 // select decay particles
383 Int_t np=fDecayer->ImportParticles(particles);
385 Int_t* pFlag = new Int_t[np];
386 Int_t* pParent = new Int_t[np];
387 Int_t* pSelected = new Int_t[np];
388 Int_t* trackIt = new Int_t[np];
390 for (i=0; i<np; i++) {
397 TParticle* iparticle = (TParticle *) particles->At(0);
399 for (i = 1; i<np ; i++) {
401 iparticle = (TParticle *) particles->At(i);
402 Int_t kf = iparticle->GetPdgCode();
403 Int_t ks = iparticle->GetStatusCode();
407 printf("\n deselected %d", i);
408 ipF = iparticle->GetFirstDaughter();
409 ipL = iparticle->GetLastDaughter();
410 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
414 // flag decay products of particles with long life-time (c tau > .3 mum)
417 TParticlePDG *particle = pDataBase->GetParticle(kf);
419 Double_t lifeTime = fDecayer->GetLifetime(kf);
420 Double_t mass = particle->Mass();
421 Double_t width = particle->Width();
422 printf("\n lifetime %d %e %e %e ", i, lifeTime, mass, width);
423 if (lifeTime > (Double_t) 1.e-15) {
424 ipF = iparticle->GetFirstDaughter();
425 ipL = iparticle->GetLastDaughter();
426 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
434 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
437 pc[0]=iparticle->Px();
438 pc[1]=iparticle->Py();
439 pc[2]=iparticle->Pz();
440 Bool_t childok = KinematicSelection(iparticle, 1);
451 } // if child selection
453 } // decay particle loop
454 } // if decay products
457 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
461 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
467 for (i = 1; i < np; i++) {
469 TParticle* iparticle = (TParticle *) particles->At(i);
470 Int_t kf = iparticle->GetPdgCode();
471 Int_t ipa = iparticle->GetFirstMother()-1;
473 och[0] = origin0[0]+iparticle->Vx()/10;
474 och[1] = origin0[1]+iparticle->Vy()/10;
475 och[2] = origin0[2]+iparticle->Vz()/10;
476 pc[0] = iparticle->Px();
477 pc[1] = iparticle->Py();
478 pc[2] = iparticle->Pz();
481 iparent = pParent[ipa];
485 printf("\n SetTrack %d %d %d %d", i, kf, iparent, trackIt[i]);
486 SetTrack(fTrackIt*trackIt[i], iparent, kf,
488 0, kPDecay, nt, wgtch);
495 if (pFlag) delete[] pFlag;
496 if (pParent) delete[] pParent;
497 if (pSelected) delete[] pSelected;
498 if (trackIt) delete[] trackIt;
499 } // kinematic selection
500 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
503 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
509 SetHighWaterMark(nt);
512 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
514 // Assignment operator