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 1.28 2001/03/09 13:01:41 morsch
19 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
20 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
22 Revision 1.27 2001/02/02 15:21:10 morsch
23 Set high water mark after last particle.
24 Use Vertex() method for Vertex.
26 Revision 1.26 2000/12/21 16:24:06 morsch
27 Coding convention clean-up
29 Revision 1.25 2000/11/30 07:12:50 alibrary
30 Introducing new Rndm and QA classes
32 Revision 1.24 2000/10/18 19:11:27 hristov
33 Division by zero fixed
35 Revision 1.23 2000/10/02 21:28:06 fca
36 Removal of useless dependecies via forward declarations
38 Revision 1.22 2000/09/12 14:14:55 morsch
39 Call fDecayer->ForceDecay() at the beginning of Generate().
41 Revision 1.21 2000/09/08 15:39:01 morsch
42 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
44 Revision 1.20 2000/09/06 14:35:44 morsch
45 Use AliDecayerPythia for particle decays.
47 Revision 1.19 2000/07/11 18:24:56 fca
48 Coding convention corrections + few minor bug fixes
50 Revision 1.18 2000/06/29 21:08:27 morsch
51 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
52 This allows to pass a pointer to a library directly to AliGenParam and avoids the
53 use of function pointers in Config.C.
55 Revision 1.17 2000/06/09 20:33:30 morsch
56 All coding rule violations except RS3 corrected
58 Revision 1.16 2000/05/02 07:51:31 morsch
59 - Control precision of pT sampling TF1::SetNpx(..)
60 - Correct initialisation of child-cuts in all constructors.
61 - Most coding rule violations corrected.
63 Revision 1.15 2000/04/03 15:42:12 morsch
64 Cuts on primary particles are separated from those on the decay products. Methods
65 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
67 Revision 1.14 1999/11/09 07:38:48 fca
68 Changes for compatibility with version 2.23 of ROOT
70 Revision 1.13 1999/11/04 11:30:31 fca
71 Correct the logics for SetForceDecay
73 Revision 1.12 1999/11/03 17:43:20 fca
74 New version from G.Martinez & A.Morsch
76 Revision 1.11 1999/09/29 09:24:14 fca
77 Introduction of the Copyright and cvs Log
81 #include "AliGenParam.h"
82 #include "AliDecayerPythia.h"
83 #include "AliGenMUONlib.h"
85 #include <TParticle.h>
86 #include <TParticlePDG.h>
87 #include <TDatabasePDG.h>
88 #include <TLorentzVector.h>
94 //------------------------------------------------------------
98 <img src="picts/AliGenParam.gif">
102 //____________________________________________________________
103 //____________________________________________________________
104 AliGenParam::AliGenParam()
106 // Deafault constructor
112 SetChildMomentumRange();
115 SetChildThetaRange();
118 // Set random number generator
122 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenerator(npart)
124 // Constructor using number of particles parameterisation id and library
126 fPtParaFunc = Library->GetPt(param, tname);
127 fYParaFunc = Library->GetY (param, tname);
128 fIpParaFunc = Library->GetIp(param, tname);
135 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
138 SetChildMomentumRange();
141 SetChildThetaRange();
144 // Set random number generator
148 //____________________________________________________________
150 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenerator(npart)
152 // Constructor using parameterisation id and number of particles
154 AliGenLib* pLibrary = new AliGenMUONlib();
156 fPtParaFunc = pLibrary->GetPt(param, tname);
157 fYParaFunc = pLibrary->GetY (param, tname);
158 fIpParaFunc = pLibrary->GetIp(param, tname);
165 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
168 SetChildMomentumRange();
171 SetChildThetaRange();
175 AliGenParam::AliGenParam(Int_t npart, Int_t param,
176 Double_t (*PtPara) (Double_t*, Double_t*),
177 Double_t (*YPara ) (Double_t* ,Double_t*),
178 Int_t (*IpPara) (TRandom *))
182 // Gines Martinez 1/10/99
183 fPtParaFunc = PtPara;
185 fIpParaFunc = IpPara;
192 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
195 SetChildMomentumRange();
198 SetChildThetaRange();
203 AliGenParam::AliGenParam(const AliGenParam & Paramd)
208 //____________________________________________________________
209 AliGenParam::~AliGenParam()
216 //____________________________________________________________
217 void AliGenParam::Init()
221 fDecayer = new AliDecayerPythia();
224 <img src="picts/AliGenParam.gif">
228 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
229 // Set representation precision to 10 MeV
230 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
232 fPtPara->SetNpx(npx);
234 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
235 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
236 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
243 fdNdy0=fYParaFunc(&y1,&y2);
245 // Integral over generation region
246 Float_t intYS = yPara ->Integral(fYMin, fYMax);
247 Float_t intPt0 = ptPara->Integral(0,15);
248 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
249 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
250 if (fAnalog == kAnalog) {
251 fYWgt = intYS/fdNdy0;
252 fPtWgt = intPtS/intPt0;
253 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
255 fYWgt = intYS/fdNdy0;
256 fPtWgt = (fPtMax-fPtMin)/intPt0;
257 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
260 // particle decay related initialization
261 fDecayer->SetForceDecay(fForceDecay);
267 case kSemiElectronic:
269 case kBJpsiDiElectron:
270 case kBPsiPrimeDiElectron:
276 case kBPsiPrimeDiMuon:
295 //____________________________________________________________
296 void AliGenParam::Generate()
299 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
300 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
301 // antineutrons in the the desired theta, phi and momentum windows;
302 // Gaussian smearing on the vertex is done if selected.
303 // The decay of heavy mesons is done using lujet,
304 // and the childern particle are tracked by GEANT
305 // However, light mesons are directly tracked by GEANT
306 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
309 // Reinitialize decayer
312 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
313 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
314 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
315 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
317 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
319 Int_t nt, i, j, kfch[10];
322 static TClonesArray *particles;
324 if(!particles) particles=new TClonesArray("TParticle",1000);
326 static TDatabasePDG *pDataBase = new TDatabasePDG();
327 if(!pDataBase) pDataBase = new TDatabasePDG();
331 // Calculating vertex position per event
332 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
333 if(fVertexSmear==kPerEvent) {
335 // for (j=0;j<3;j++) {
336 // origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
337 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
338 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
342 for (j=0;j<3;j++) origin0[j]=fVertex[j];
346 // Generating fNpart particles
351 Int_t iPart = fIpParaFunc(fRandom);
352 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
353 TParticlePDG *particle = pDataBase->GetParticle(iPart);
354 Float_t am = particle->Mass();
359 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
362 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
365 if (fAnalog == kAnalog) {
366 pt=fPtPara->GetRandom();
370 pt=fPtMin+random[1]*(fPtMax-fPtMin);
372 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
373 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
375 xmt=sqrt(pt*pt+am*am);
376 if (TMath::Abs(ty)==1) ty=0;
377 pl=xmt*ty/sqrt(1.-ty*ty);
378 theta=TMath::ATan2(pt,pl);
380 if(theta<fThetaMin || theta>fThetaMax) continue;
381 ptot=TMath::Sqrt(pt*pt+pl*pl);
383 if(ptot<fPMin || ptot>fPMax) continue;
384 p[0]=pt*TMath::Cos(phi);
385 p[1]=pt*TMath::Sin(phi);
387 if(fVertexSmear==kPerTrack) {
391 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
392 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
396 // Looking at fForceDecay :
397 // if fForceDecay != none Primary particle decays using
398 // AliPythia and children are tracked by GEANT
400 // if fForceDecay == none Primary particle is tracked by GEANT
401 // (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 for (i = 1; i<np; i++) {
413 TParticle * iparticle = (TParticle *) particles->At(i);
414 Int_t kf = iparticle->GetPdgCode();
417 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll)
419 pc[0]=iparticle->Px();
420 pc[1]=iparticle->Py();
421 pc[2]=iparticle->Pz();
422 och[0]=origin0[0]+iparticle->Vx()/10;
423 och[1]=origin0[1]+iparticle->Vy()/10;
424 och[2]=origin0[2]+iparticle->Vz()/10;
426 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
427 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
428 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
429 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
431 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
432 (pChild > fChildPMin && pChild <fChildPMax) &&
433 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
434 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
452 } // if child selection
454 } // decay particle loop
456 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
461 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
463 gAlice->KeepTrack(nt);
464 for (i=0; i< ncsel; i++) {
465 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
466 &pch[i][0],och,polar,
468 gAlice->KeepTrack(nt);
471 } // kinematic selection
472 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
475 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
481 gAlice->SetHighWaterMark(nt);
485 Bool_t AliGenParam::ChildSelected(Int_t ip)
487 // True if particle is in list of selected children
488 for (Int_t i=0; i<5; i++)
490 if (fChildSelect[i]==ip) return kTRUE;
495 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
497 // Perform kinematic cuts
498 Float_t px=particle->Px();
499 Float_t py=particle->Py();
500 Float_t pz=particle->Pz();
503 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
504 if (p > fPMax || p < fPMin)
506 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
509 Float_t pt=TMath::Sqrt(px*px+py*py);
513 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
514 if (theta > fThetaMax || theta < fThetaMin)
516 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
524 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
526 // Assignment operator