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 1.25 2000/11/30 07:12:50 alibrary
19 Introducing new Rndm and QA classes
21 Revision 1.24 2000/10/18 19:11:27 hristov
22 Division by zero fixed
24 Revision 1.23 2000/10/02 21:28:06 fca
25 Removal of useless dependecies via forward declarations
27 Revision 1.22 2000/09/12 14:14:55 morsch
28 Call fDecayer->ForceDecay() at the beginning of Generate().
30 Revision 1.21 2000/09/08 15:39:01 morsch
31 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
33 Revision 1.20 2000/09/06 14:35:44 morsch
34 Use AliDecayerPythia for particle decays.
36 Revision 1.19 2000/07/11 18:24:56 fca
37 Coding convention corrections + few minor bug fixes
39 Revision 1.18 2000/06/29 21:08:27 morsch
40 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
41 This allows to pass a pointer to a library directly to AliGenParam and avoids the
42 use of function pointers in Config.C.
44 Revision 1.17 2000/06/09 20:33:30 morsch
45 All coding rule violations except RS3 corrected
47 Revision 1.16 2000/05/02 07:51:31 morsch
48 - Control precision of pT sampling TF1::SetNpx(..)
49 - Correct initialisation of child-cuts in all constructors.
50 - Most coding rule violations corrected.
52 Revision 1.15 2000/04/03 15:42:12 morsch
53 Cuts on primary particles are separated from those on the decay products. Methods
54 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
56 Revision 1.14 1999/11/09 07:38:48 fca
57 Changes for compatibility with version 2.23 of ROOT
59 Revision 1.13 1999/11/04 11:30:31 fca
60 Correct the logics for SetForceDecay
62 Revision 1.12 1999/11/03 17:43:20 fca
63 New version from G.Martinez & A.Morsch
65 Revision 1.11 1999/09/29 09:24:14 fca
66 Introduction of the Copyright and cvs Log
70 #include "AliGenParam.h"
71 #include "AliDecayerPythia.h"
72 #include "AliGenMUONlib.h"
74 #include <TParticle.h>
75 #include <TParticlePDG.h>
76 #include <TDatabasePDG.h>
77 #include <TLorentzVector.h>
83 //------------------------------------------------------------
87 <img src="picts/AliGenParam.gif">
91 //____________________________________________________________
92 //____________________________________________________________
93 AliGenParam::AliGenParam()
95 // Deafault constructor
101 SetChildMomentumRange();
104 SetChildThetaRange();
107 // Set random number generator
111 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
113 // Constructor using number of particles parameterisation id and library
115 fPtParaFunc = Library->GetPt(param, tname);
116 fYParaFunc = Library->GetY (param, tname);
117 fIpParaFunc = Library->GetIp(param, tname);
124 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
127 SetChildMomentumRange();
130 SetChildThetaRange();
133 // Set random number generator
137 //____________________________________________________________
139 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
141 // Constructor using parameterisation id and number of particles
143 AliGenLib* pLibrary = new AliGenMUONlib();
145 fPtParaFunc = pLibrary->GetPt(param, tname);
146 fYParaFunc = pLibrary->GetY (param, tname);
147 fIpParaFunc = pLibrary->GetIp(param, tname);
154 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
157 SetChildMomentumRange();
160 SetChildThetaRange();
164 AliGenParam::AliGenParam(Int_t npart, Param_t param,
165 Double_t (*PtPara) (Double_t*, Double_t*),
166 Double_t (*YPara ) (Double_t* ,Double_t*),
167 Int_t (*IpPara) (TRandom *))
171 // Gines Martinez 1/10/99
172 fPtParaFunc = PtPara;
174 fIpParaFunc = IpPara;
181 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
184 SetChildMomentumRange();
187 SetChildThetaRange();
192 AliGenParam::AliGenParam(const AliGenParam & Paramd)
197 //____________________________________________________________
198 AliGenParam::~AliGenParam()
205 //____________________________________________________________
206 void AliGenParam::Init()
210 fDecayer = new AliDecayerPythia();
213 <img src="picts/AliGenParam.gif">
217 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
218 // Set representation precision to 10 MeV
219 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
221 fPtPara->SetNpx(npx);
223 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
224 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
225 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
232 fdNdy0=fYParaFunc(&y1,&y2);
234 // Integral over generation region
235 Float_t intYS = yPara ->Integral(fYMin, fYMax);
236 Float_t intPt0 = ptPara->Integral(0,15);
237 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
238 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
239 if (fAnalog == analog) {
240 fYWgt = intYS/fdNdy0;
241 fPtWgt = intPtS/intPt0;
242 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
244 fYWgt = intYS/fdNdy0;
245 fPtWgt = (fPtMax-fPtMin)/intPt0;
246 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
249 // particle decay related initialization
250 fDecayer->SetForceDecay(fForceDecay);
258 case b_jpsi_dielectron:
259 case b_psip_dielectron:
284 //____________________________________________________________
285 void AliGenParam::Generate()
288 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
289 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
290 // antineutrons in the the desired theta, phi and momentum windows;
291 // Gaussian smearing on the vertex is done if selected.
292 // The decay of heavy mesons is done using lujet,
293 // and the childern particle are tracked by GEANT
294 // However, light mesons are directly tracked by GEANT
295 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
298 fDecayer->ForceDecay();
299 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
300 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
301 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
302 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
304 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
306 Int_t nt, i, j, kfch[10];
309 static TClonesArray *particles;
311 if(!particles) particles=new TClonesArray("TParticle",1000);
313 static TDatabasePDG *pDataBase = new TDatabasePDG();
314 if(!pDataBase) pDataBase = new TDatabasePDG();
318 // Calculating vertex position per event
319 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
320 if(fVertexSmear==kPerEvent) {
323 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
324 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
328 // Generating fNpart particles
333 Int_t iPart = fIpParaFunc(fRandom);
334 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
335 TParticlePDG *particle = pDataBase->GetParticle(iPart);
336 Float_t am = particle->Mass();
341 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
344 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
347 if (fAnalog == analog) {
348 pt=fPtPara->GetRandom();
352 pt=fPtMin+random[1]*(fPtMax-fPtMin);
354 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
355 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
357 xmt=sqrt(pt*pt+am*am);
358 if (TMath::Abs(ty)==1) ty=0;
359 pl=xmt*ty/sqrt(1.-ty*ty);
360 theta=TMath::ATan2(pt,pl);
362 if(theta<fThetaMin || theta>fThetaMax) continue;
363 ptot=TMath::Sqrt(pt*pt+pl*pl);
365 if(ptot<fPMin || ptot>fPMax) continue;
366 p[0]=pt*TMath::Cos(phi);
367 p[1]=pt*TMath::Sin(phi);
369 if(fVertexSmear==kPerTrack) {
373 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
374 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
378 // Looking at fForceDecay :
379 // if fForceDecay != none Primary particle decays using
380 // AliPythia and children are tracked by GEANT
382 // if fForceDecay == none Primary particle is tracked by GEANT
383 // (In the latest, make sure that GEANT actually does all the decays you want)
385 if (fForceDecay != nodecay) {
386 // Using lujet to decay particle
387 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
388 TLorentzVector pmom(p[0], p[1], p[2], energy);
389 fDecayer->Decay(iPart,&pmom);
391 // select decay particles
392 Int_t np=fDecayer->ImportParticles(particles);
394 for (i = 1; i<np; i++) {
395 TParticle * iparticle = (TParticle *) particles->At(i);
396 Int_t kf = iparticle->GetPdgCode();
399 if (ChildSelected(TMath::Abs(kf)) || fForceDecay==all)
401 pc[0]=iparticle->Px();
402 pc[1]=iparticle->Py();
403 pc[2]=iparticle->Pz();
404 och[0]=origin0[0]+iparticle->Vx()/10;
405 och[1]=origin0[1]+iparticle->Vy()/10;
406 och[2]=origin0[2]+iparticle->Vz()/10;
408 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
409 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
410 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
411 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
413 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
414 (pChild > fChildPMin && pChild <fChildPMax) &&
415 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
416 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
434 } // if child selection
436 } // decay particle loop
438 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
443 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
445 gAlice->KeepTrack(nt);
446 for (i=0; i< ncsel; i++) {
447 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
448 &pch[i][0],och,polar,
450 gAlice->KeepTrack(nt);
453 } // kinematic selection
454 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
457 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
465 Bool_t AliGenParam::ChildSelected(Int_t ip)
467 // True if particle is in list of selected children
468 for (Int_t i=0; i<5; i++)
470 if (fChildSelect[i]==ip) return kTRUE;
475 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
477 // Perform kinematic cuts
478 Float_t px=particle->Px();
479 Float_t py=particle->Py();
480 Float_t pz=particle->Pz();
483 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
484 if (p > fPMax || p < fPMin)
486 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
489 Float_t pt=TMath::Sqrt(px*px+py*py);
493 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
494 if (theta > fThetaMax || theta < fThetaMin)
496 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
504 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
506 // Assignment operator