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 1.29 2001/03/27 10:58:41 morsch
19 Initialize decayer before generation. Important if run inside cocktail.
21 Revision 1.28 2001/03/09 13:01:41 morsch
22 - enum constants for paramterisation type (particle family) moved to AliGen*lib.h
23 - use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
25 Revision 1.27 2001/02/02 15:21:10 morsch
26 Set high water mark after last particle.
27 Use Vertex() method for Vertex.
29 Revision 1.26 2000/12/21 16:24:06 morsch
30 Coding convention clean-up
32 Revision 1.25 2000/11/30 07:12:50 alibrary
33 Introducing new Rndm and QA classes
35 Revision 1.24 2000/10/18 19:11:27 hristov
36 Division by zero fixed
38 Revision 1.23 2000/10/02 21:28:06 fca
39 Removal of useless dependecies via forward declarations
41 Revision 1.22 2000/09/12 14:14:55 morsch
42 Call fDecayer->ForceDecay() at the beginning of Generate().
44 Revision 1.21 2000/09/08 15:39:01 morsch
45 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
47 Revision 1.20 2000/09/06 14:35:44 morsch
48 Use AliDecayerPythia for particle decays.
50 Revision 1.19 2000/07/11 18:24:56 fca
51 Coding convention corrections + few minor bug fixes
53 Revision 1.18 2000/06/29 21:08:27 morsch
54 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
55 This allows to pass a pointer to a library directly to AliGenParam and avoids the
56 use of function pointers in Config.C.
58 Revision 1.17 2000/06/09 20:33:30 morsch
59 All coding rule violations except RS3 corrected
61 Revision 1.16 2000/05/02 07:51:31 morsch
62 - Control precision of pT sampling TF1::SetNpx(..)
63 - Correct initialisation of child-cuts in all constructors.
64 - Most coding rule violations corrected.
66 Revision 1.15 2000/04/03 15:42:12 morsch
67 Cuts on primary particles are separated from those on the decay products. Methods
68 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
70 Revision 1.14 1999/11/09 07:38:48 fca
71 Changes for compatibility with version 2.23 of ROOT
73 Revision 1.13 1999/11/04 11:30:31 fca
74 Correct the logics for SetForceDecay
76 Revision 1.12 1999/11/03 17:43:20 fca
77 New version from G.Martinez & A.Morsch
79 Revision 1.11 1999/09/29 09:24:14 fca
80 Introduction of the Copyright and cvs Log
84 #include "AliGenParam.h"
85 #include "AliDecayerPythia.h"
86 #include "AliGenMUONlib.h"
88 #include <TParticle.h>
89 #include <TParticlePDG.h>
90 #include <TDatabasePDG.h>
91 #include <TLorentzVector.h>
97 //------------------------------------------------------------
101 <img src="picts/AliGenParam.gif">
105 //____________________________________________________________
106 //____________________________________________________________
107 AliGenParam::AliGenParam()
109 // Deafault constructor
115 SetChildMomentumRange();
118 SetChildThetaRange();
121 // Set random number generator
125 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenerator(npart)
127 // Constructor using number of particles parameterisation id and library
129 fPtParaFunc = Library->GetPt(param, tname);
130 fYParaFunc = Library->GetY (param, tname);
131 fIpParaFunc = Library->GetIp(param, tname);
138 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
141 SetChildMomentumRange();
144 SetChildThetaRange();
147 // Set random number generator
151 //____________________________________________________________
153 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenerator(npart)
155 // Constructor using parameterisation id and number of particles
157 AliGenLib* pLibrary = new AliGenMUONlib();
159 fPtParaFunc = pLibrary->GetPt(param, tname);
160 fYParaFunc = pLibrary->GetY (param, tname);
161 fIpParaFunc = pLibrary->GetIp(param, tname);
168 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
171 SetChildMomentumRange();
174 SetChildThetaRange();
178 AliGenParam::AliGenParam(Int_t npart, Int_t param,
179 Double_t (*PtPara) (Double_t*, Double_t*),
180 Double_t (*YPara ) (Double_t* ,Double_t*),
181 Int_t (*IpPara) (TRandom *))
185 // Gines Martinez 1/10/99
186 fPtParaFunc = PtPara;
188 fIpParaFunc = IpPara;
195 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
198 SetChildMomentumRange();
201 SetChildThetaRange();
206 AliGenParam::AliGenParam(const AliGenParam & Paramd)
211 //____________________________________________________________
212 AliGenParam::~AliGenParam()
219 //____________________________________________________________
220 void AliGenParam::Init()
224 fDecayer = new AliDecayerPythia();
227 <img src="picts/AliGenParam.gif">
231 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
232 // Set representation precision to 10 MeV
233 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
235 fPtPara->SetNpx(npx);
237 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
238 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
239 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
246 fdNdy0=fYParaFunc(&y1,&y2);
248 // Integral over generation region
249 Float_t intYS = yPara ->Integral(fYMin, fYMax);
250 Float_t intPt0 = ptPara->Integral(0,15);
251 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
252 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
253 if (fAnalog == kAnalog) {
254 fYWgt = intYS/fdNdy0;
255 fPtWgt = intPtS/intPt0;
256 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
258 fYWgt = intYS/fdNdy0;
259 fPtWgt = (fPtMax-fPtMin)/intPt0;
260 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
263 // particle decay related initialization
264 fDecayer->SetForceDecay(fForceDecay);
270 case kSemiElectronic:
272 case kBJpsiDiElectron:
273 case kBPsiPrimeDiElectron:
279 case kBPsiPrimeDiMuon:
298 //____________________________________________________________
299 void AliGenParam::Generate()
302 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
303 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
304 // antineutrons in the the desired theta, phi and momentum windows;
305 // Gaussian smearing on the vertex is done if selected.
306 // The decay of heavy mesons is done using lujet,
307 // and the childern particle are tracked by GEANT
308 // However, light mesons are directly tracked by GEANT
309 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
312 // Reinitialize decayer
315 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
316 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
317 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
318 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
320 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
322 Int_t nt, i, j, kfch[10];
325 static TClonesArray *particles;
327 if(!particles) particles=new TClonesArray("TParticle",1000);
329 static TDatabasePDG *pDataBase = new TDatabasePDG();
330 if(!pDataBase) pDataBase = new TDatabasePDG();
334 // Calculating vertex position per event
335 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
336 if(fVertexSmear==kPerEvent) {
338 // for (j=0;j<3;j++) {
339 // origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
340 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
341 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
345 for (j=0;j<3;j++) origin0[j]=fVertex[j];
349 // Generating fNpart particles
354 Int_t iPart = fIpParaFunc(fRandom);
355 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
356 TParticlePDG *particle = pDataBase->GetParticle(iPart);
357 Float_t am = particle->Mass();
362 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
365 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
368 if (fAnalog == kAnalog) {
369 pt=fPtPara->GetRandom();
373 pt=fPtMin+random[1]*(fPtMax-fPtMin);
375 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
376 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
378 xmt=sqrt(pt*pt+am*am);
379 if (TMath::Abs(ty)==1) ty=0;
380 pl=xmt*ty/sqrt(1.-ty*ty);
381 theta=TMath::ATan2(pt,pl);
383 if(theta<fThetaMin || theta>fThetaMax) continue;
384 ptot=TMath::Sqrt(pt*pt+pl*pl);
386 if(ptot<fPMin || ptot>fPMax) continue;
387 p[0]=pt*TMath::Cos(phi);
388 p[1]=pt*TMath::Sin(phi);
390 if(fVertexSmear==kPerTrack) {
394 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
395 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
399 // Looking at fForceDecay :
400 // if fForceDecay != none Primary particle decays using
401 // AliPythia and children are tracked by GEANT
403 // if fForceDecay == none Primary particle is tracked by GEANT
404 // (In the latest, make sure that GEANT actually does all the decays you want)
406 if (fForceDecay != kNoDecay) {
407 // Using lujet to decay particle
408 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
409 TLorentzVector pmom(p[0], p[1], p[2], energy);
410 fDecayer->Decay(iPart,&pmom);
412 // select decay particles
413 Int_t np=fDecayer->ImportParticles(particles);
417 TParticle* iparticle = (TParticle *) particles->At(0);
418 Int_t ipF = iparticle->GetFirstDaughter();
419 Int_t ipL = iparticle->GetLastDaughter();
420 for (i = ipF-1; i<ipL; i++) {
421 iparticle = (TParticle *) particles->At(i);
422 Int_t kf = iparticle->GetPdgCode();
425 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll)
427 pc[0]=iparticle->Px();
428 pc[1]=iparticle->Py();
429 pc[2]=iparticle->Pz();
430 och[0]=origin0[0]+iparticle->Vx()/10;
431 och[1]=origin0[1]+iparticle->Vy()/10;
432 och[2]=origin0[2]+iparticle->Vz()/10;
434 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
435 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
436 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
437 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
439 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
440 (pChild > fChildPMin && pChild <fChildPMax) &&
441 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
442 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
460 } // if child selection
462 } // decay particle loop
463 } // if decay products
466 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
471 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
473 gAlice->KeepTrack(nt);
474 for (i=0; i< ncsel; i++) {
475 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
476 &pch[i][0],och,polar,
478 gAlice->KeepTrack(nt);
481 } // kinematic selection
482 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
485 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
491 gAlice->SetHighWaterMark(nt);
495 Bool_t AliGenParam::ChildSelected(Int_t ip)
497 // True if particle is in list of selected children
498 for (Int_t i=0; i<5; i++)
500 if (fChildSelect[i]==ip) return kTRUE;
505 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
507 // Perform kinematic cuts
508 Float_t px=particle->Px();
509 Float_t py=particle->Py();
510 Float_t pz=particle->Pz();
513 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
514 if (p > fPMax || p < fPMin)
516 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
519 Float_t pt=TMath::Sqrt(px*px+py*py);
523 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
524 if (theta > fThetaMax || theta < fThetaMin)
526 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
534 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
536 // Assignment operator