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 1.20 2000/09/06 14:35:44 morsch
19 Use AliDecayerPythia for particle decays.
21 Revision 1.19 2000/07/11 18:24:56 fca
22 Coding convention corrections + few minor bug fixes
24 Revision 1.18 2000/06/29 21:08:27 morsch
25 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
26 This allows to pass a pointer to a library directly to AliGenParam and avoids the
27 use of function pointers in Config.C.
29 Revision 1.17 2000/06/09 20:33:30 morsch
30 All coding rule violations except RS3 corrected
32 Revision 1.16 2000/05/02 07:51:31 morsch
33 - Control precision of pT sampling TF1::SetNpx(..)
34 - Correct initialisation of child-cuts in all constructors.
35 - Most coding rule violations corrected.
37 Revision 1.15 2000/04/03 15:42:12 morsch
38 Cuts on primary particles are separated from those on the decay products. Methods
39 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
41 Revision 1.14 1999/11/09 07:38:48 fca
42 Changes for compatibility with version 2.23 of ROOT
44 Revision 1.13 1999/11/04 11:30:31 fca
45 Correct the logics for SetForceDecay
47 Revision 1.12 1999/11/03 17:43:20 fca
48 New version from G.Martinez & A.Morsch
50 Revision 1.11 1999/09/29 09:24:14 fca
51 Introduction of the Copyright and cvs Log
55 #include "AliGenParam.h"
56 #include "AliDecayerPythia.h"
57 #include "AliGenMUONlib.h"
59 #include "AliPythia.h"
60 #include <TParticle.h>
61 #include <TParticlePDG.h>
62 #include <TDatabasePDG.h>
63 #include <TLorentzVector.h>
69 //------------------------------------------------------------
73 <img src="picts/AliGenParam.gif">
77 //____________________________________________________________
78 //____________________________________________________________
79 AliGenParam::AliGenParam()
82 // Deafault constructor
88 SetChildMomentumRange();
95 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
97 // Constructor using number of particles parameterisation id and library
99 fPtParaFunc = Library->GetPt(param, tname);
100 fYParaFunc = Library->GetY (param, tname);
101 fIpParaFunc = Library->GetIp(param, tname);
108 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
111 SetChildMomentumRange();
114 SetChildThetaRange();
118 //____________________________________________________________
120 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
122 // Constructor using parameterisation id and number of particles
124 AliGenLib* Library = new AliGenMUONlib();
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();
145 AliGenParam::AliGenParam(Int_t npart, Param_t param,
146 Double_t (*PtPara) (Double_t*, Double_t*),
147 Double_t (*YPara ) (Double_t* ,Double_t*),
152 // Gines Martinez 1/10/99
153 fPtParaFunc = PtPara;
155 fIpParaFunc = IpPara;
162 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
165 SetChildMomentumRange();
168 SetChildThetaRange();
173 AliGenParam::AliGenParam(const AliGenParam & Paramd)
178 //____________________________________________________________
179 AliGenParam::~AliGenParam()
186 //____________________________________________________________
187 void AliGenParam::Init()
191 fDecayer = new AliDecayerPythia();
194 <img src="picts/AliGenParam.gif">
198 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
199 // Set representation precision to 10 MeV
200 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
202 fPtPara->SetNpx(npx);
204 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
205 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
206 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
213 fdNdy0=fYParaFunc(&y1,&y2);
215 // Integral over generation region
216 Float_t intYS = yPara ->Integral(fYMin, fYMax);
217 Float_t intPt0 = ptPara->Integral(0,15);
218 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
219 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
220 if (fAnalog == analog) {
221 fYWgt = intYS/fdNdy0;
222 fPtWgt = intPtS/intPt0;
223 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
225 fYWgt = intYS/fdNdy0;
226 fPtWgt = (fPtMax-fPtMin)/intPt0;
227 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
230 // particle decay related initialization
232 // semimuonic decays of charm and beauty
233 fDecayer->ForceDecay(fForceDecay);
239 case b_jpsi_dielectron:
240 case b_psip_dielectron:
262 //____________________________________________________________
263 void AliGenParam::Generate()
266 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
267 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
268 // antineutrons in the the desired theta, phi and momentum windows;
269 // Gaussian smearing on the vertex is done if selected.
270 // The decay of heavy mesons is done using lujet,
271 // and the childern particle are tracked by GEANT
272 // However, light mesons are directly tracked by GEANT
273 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
277 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
278 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
279 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
280 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
282 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
284 Int_t nt, i, j, kfch[10];
287 static TClonesArray *particles;
289 if(!particles) particles=new TClonesArray("TParticle",1000);
291 static TDatabasePDG *DataBase = new TDatabasePDG();
292 if(!DataBase) DataBase = new TDatabasePDG();
296 // Calculating vertex position per event
297 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
298 if(fVertexSmear==kPerEvent) {
301 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
302 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
306 // Generating fNpart particles
311 Int_t iPart = fIpParaFunc();
312 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
313 TParticlePDG *particle = DataBase->GetParticle(iPart);
314 Float_t am = particle->Mass();
319 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
322 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
325 if (fAnalog == analog) {
326 pt=fPtPara->GetRandom();
330 pt=fPtMin+random[1]*(fPtMax-fPtMin);
332 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
333 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
335 xmt=sqrt(pt*pt+am*am);
336 pl=xmt*ty/sqrt(1.-ty*ty);
337 theta=TMath::ATan2(pt,pl);
339 if(theta<fThetaMin || theta>fThetaMax) continue;
340 ptot=TMath::Sqrt(pt*pt+pl*pl);
342 if(ptot<fPMin || ptot>fPMax) continue;
343 p[0]=pt*TMath::Cos(phi);
344 p[1]=pt*TMath::Sin(phi);
346 if(fVertexSmear==kPerTrack) {
350 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
351 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
355 // Looking at fForceDecay :
356 // if fForceDecay != none Primary particle decays using
357 // AliPythia and children are tracked by GEANT
359 // if fForceDecay == none Primary particle is tracked by GEANT
360 // (In the latest, make sure that GEANT actually does all the decays you want)
362 if (fForceDecay != nodecay) {
363 // Using lujet to decay particle
364 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
365 TLorentzVector pmom(p[0], p[1], p[2], energy);
366 fDecayer->Decay(iPart,&pmom);
368 // select decay particles
369 Int_t np=fDecayer->ImportParticles(particles);
371 for (i = 1; i<np; i++) {
372 TParticle * iparticle = (TParticle *) particles->At(i);
373 Int_t kf = iparticle->GetPdgCode();
376 if (ChildSelected(TMath::Abs(kf)) || fForceDecay==all)
378 pc[0]=iparticle->Px();
379 pc[1]=iparticle->Py();
380 pc[2]=iparticle->Pz();
381 och[0]=origin0[0]+iparticle->Vx()/10;
382 och[1]=origin0[1]+iparticle->Vy()/10;
383 och[2]=origin0[2]+iparticle->Vz()/10;
385 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
386 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
387 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
388 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
390 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
391 (pChild > fChildPMin && pChild <fChildPMax) &&
392 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
393 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
411 } // if child selection
413 } // decay particle loop
415 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
420 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
422 gAlice->KeepTrack(nt);
423 for (i=0; i< ncsel; i++) {
424 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
425 &pch[i][0],och,polar,
427 gAlice->KeepTrack(nt);
430 } // kinematic selection
431 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
434 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
442 Bool_t AliGenParam::ChildSelected(Int_t ip)
444 // True if particle is in list of selected children
445 for (Int_t i=0; i<5; i++)
447 if (fChildSelect[i]==ip) return kTRUE;
452 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
454 // Perform kinematic cuts
455 Float_t px=particle->Px();
456 Float_t py=particle->Py();
457 Float_t pz=particle->Pz();
460 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
461 if (p > fPMax || p < fPMin)
463 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
466 Float_t pt=TMath::Sqrt(px*px+py*py);
470 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
471 if (theta > fThetaMax || theta < fThetaMin)
473 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
481 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
483 // Assignment operator