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 1.27 2001/02/02 15:21:10 morsch
19 Set high water mark after last particle.
20 Use Vertex() method for Vertex.
22 Revision 1.26 2000/12/21 16:24:06 morsch
23 Coding convention clean-up
25 Revision 1.25 2000/11/30 07:12:50 alibrary
26 Introducing new Rndm and QA classes
28 Revision 1.24 2000/10/18 19:11:27 hristov
29 Division by zero fixed
31 Revision 1.23 2000/10/02 21:28:06 fca
32 Removal of useless dependecies via forward declarations
34 Revision 1.22 2000/09/12 14:14:55 morsch
35 Call fDecayer->ForceDecay() at the beginning of Generate().
37 Revision 1.21 2000/09/08 15:39:01 morsch
38 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
40 Revision 1.20 2000/09/06 14:35:44 morsch
41 Use AliDecayerPythia for particle decays.
43 Revision 1.19 2000/07/11 18:24:56 fca
44 Coding convention corrections + few minor bug fixes
46 Revision 1.18 2000/06/29 21:08:27 morsch
47 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
48 This allows to pass a pointer to a library directly to AliGenParam and avoids the
49 use of function pointers in Config.C.
51 Revision 1.17 2000/06/09 20:33:30 morsch
52 All coding rule violations except RS3 corrected
54 Revision 1.16 2000/05/02 07:51:31 morsch
55 - Control precision of pT sampling TF1::SetNpx(..)
56 - Correct initialisation of child-cuts in all constructors.
57 - Most coding rule violations corrected.
59 Revision 1.15 2000/04/03 15:42:12 morsch
60 Cuts on primary particles are separated from those on the decay products. Methods
61 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
63 Revision 1.14 1999/11/09 07:38:48 fca
64 Changes for compatibility with version 2.23 of ROOT
66 Revision 1.13 1999/11/04 11:30:31 fca
67 Correct the logics for SetForceDecay
69 Revision 1.12 1999/11/03 17:43:20 fca
70 New version from G.Martinez & A.Morsch
72 Revision 1.11 1999/09/29 09:24:14 fca
73 Introduction of the Copyright and cvs Log
77 #include "AliGenParam.h"
78 #include "AliDecayerPythia.h"
79 #include "AliGenMUONlib.h"
81 #include <TParticle.h>
82 #include <TParticlePDG.h>
83 #include <TDatabasePDG.h>
84 #include <TLorentzVector.h>
90 //------------------------------------------------------------
94 <img src="picts/AliGenParam.gif">
98 //____________________________________________________________
99 //____________________________________________________________
100 AliGenParam::AliGenParam()
102 // Deafault constructor
108 SetChildMomentumRange();
111 SetChildThetaRange();
114 // Set random number generator
118 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenerator(npart)
120 // Constructor using number of particles parameterisation id and library
122 fPtParaFunc = Library->GetPt(param, tname);
123 fYParaFunc = Library->GetY (param, tname);
124 fIpParaFunc = Library->GetIp(param, tname);
131 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
134 SetChildMomentumRange();
137 SetChildThetaRange();
140 // Set random number generator
144 //____________________________________________________________
146 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenerator(npart)
148 // Constructor using parameterisation id and number of particles
150 AliGenLib* pLibrary = new AliGenMUONlib();
152 fPtParaFunc = pLibrary->GetPt(param, tname);
153 fYParaFunc = pLibrary->GetY (param, tname);
154 fIpParaFunc = pLibrary->GetIp(param, tname);
161 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
164 SetChildMomentumRange();
167 SetChildThetaRange();
171 AliGenParam::AliGenParam(Int_t npart, Int_t param,
172 Double_t (*PtPara) (Double_t*, Double_t*),
173 Double_t (*YPara ) (Double_t* ,Double_t*),
174 Int_t (*IpPara) (TRandom *))
178 // Gines Martinez 1/10/99
179 fPtParaFunc = PtPara;
181 fIpParaFunc = IpPara;
188 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
191 SetChildMomentumRange();
194 SetChildThetaRange();
199 AliGenParam::AliGenParam(const AliGenParam & Paramd)
204 //____________________________________________________________
205 AliGenParam::~AliGenParam()
212 //____________________________________________________________
213 void AliGenParam::Init()
217 fDecayer = new AliDecayerPythia();
220 <img src="picts/AliGenParam.gif">
224 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
225 // Set representation precision to 10 MeV
226 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
228 fPtPara->SetNpx(npx);
230 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
231 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
232 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
239 fdNdy0=fYParaFunc(&y1,&y2);
241 // Integral over generation region
242 Float_t intYS = yPara ->Integral(fYMin, fYMax);
243 Float_t intPt0 = ptPara->Integral(0,15);
244 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
245 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
246 if (fAnalog == kAnalog) {
247 fYWgt = intYS/fdNdy0;
248 fPtWgt = intPtS/intPt0;
249 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
251 fYWgt = intYS/fdNdy0;
252 fPtWgt = (fPtMax-fPtMin)/intPt0;
253 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
256 // particle decay related initialization
257 fDecayer->SetForceDecay(fForceDecay);
263 case kSemiElectronic:
265 case kBJpsiDiElectron:
266 case kBPsiPrimeDiElectron:
272 case kBPsiPrimeDiMuon:
291 //____________________________________________________________
292 void AliGenParam::Generate()
295 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
296 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
297 // antineutrons in the the desired theta, phi and momentum windows;
298 // Gaussian smearing on the vertex is done if selected.
299 // The decay of heavy mesons is done using lujet,
300 // and the childern particle are tracked by GEANT
301 // However, light mesons are directly tracked by GEANT
302 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
305 fDecayer->ForceDecay();
306 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
307 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
308 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
309 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
311 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
313 Int_t nt, i, j, kfch[10];
316 static TClonesArray *particles;
318 if(!particles) particles=new TClonesArray("TParticle",1000);
320 static TDatabasePDG *pDataBase = new TDatabasePDG();
321 if(!pDataBase) pDataBase = new TDatabasePDG();
325 // Calculating vertex position per event
326 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
327 if(fVertexSmear==kPerEvent) {
329 // for (j=0;j<3;j++) {
330 // origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
331 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
332 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
336 for (j=0;j<3;j++) origin0[j]=fVertex[j];
340 // Generating fNpart particles
345 Int_t iPart = fIpParaFunc(fRandom);
346 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
347 TParticlePDG *particle = pDataBase->GetParticle(iPart);
348 Float_t am = particle->Mass();
353 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
356 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
359 if (fAnalog == kAnalog) {
360 pt=fPtPara->GetRandom();
364 pt=fPtMin+random[1]*(fPtMax-fPtMin);
366 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
367 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
369 xmt=sqrt(pt*pt+am*am);
370 if (TMath::Abs(ty)==1) ty=0;
371 pl=xmt*ty/sqrt(1.-ty*ty);
372 theta=TMath::ATan2(pt,pl);
374 if(theta<fThetaMin || theta>fThetaMax) continue;
375 ptot=TMath::Sqrt(pt*pt+pl*pl);
377 if(ptot<fPMin || ptot>fPMax) continue;
378 p[0]=pt*TMath::Cos(phi);
379 p[1]=pt*TMath::Sin(phi);
381 if(fVertexSmear==kPerTrack) {
385 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
386 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
390 // Looking at fForceDecay :
391 // if fForceDecay != none Primary particle decays using
392 // AliPythia and children are tracked by GEANT
394 // if fForceDecay == none Primary particle is tracked by GEANT
395 // (In the latest, make sure that GEANT actually does all the decays you want)
397 if (fForceDecay != kNoDecay) {
398 // Using lujet to decay particle
399 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
400 TLorentzVector pmom(p[0], p[1], p[2], energy);
401 fDecayer->Decay(iPart,&pmom);
403 // select decay particles
404 Int_t np=fDecayer->ImportParticles(particles);
406 for (i = 1; i<np; i++) {
407 TParticle * iparticle = (TParticle *) particles->At(i);
408 Int_t kf = iparticle->GetPdgCode();
411 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll)
413 pc[0]=iparticle->Px();
414 pc[1]=iparticle->Py();
415 pc[2]=iparticle->Pz();
416 och[0]=origin0[0]+iparticle->Vx()/10;
417 och[1]=origin0[1]+iparticle->Vy()/10;
418 och[2]=origin0[2]+iparticle->Vz()/10;
420 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
421 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
422 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
423 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
425 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
426 (pChild > fChildPMin && pChild <fChildPMax) &&
427 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
428 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
446 } // if child selection
448 } // decay particle loop
450 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
455 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
457 gAlice->KeepTrack(nt);
458 for (i=0; i< ncsel; i++) {
459 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
460 &pch[i][0],och,polar,
462 gAlice->KeepTrack(nt);
465 } // kinematic selection
466 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
469 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
475 gAlice->SetHighWaterMark(nt);
479 Bool_t AliGenParam::ChildSelected(Int_t ip)
481 // True if particle is in list of selected children
482 for (Int_t i=0; i<5; i++)
484 if (fChildSelect[i]==ip) return kTRUE;
489 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
491 // Perform kinematic cuts
492 Float_t px=particle->Px();
493 Float_t py=particle->Py();
494 Float_t pz=particle->Pz();
497 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
498 if (p > fPMax || p < fPMin)
500 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
503 Float_t pt=TMath::Sqrt(px*px+py*py);
507 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
508 if (theta > fThetaMax || theta < fThetaMin)
510 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
518 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
520 // Assignment operator