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 1.21 2000/09/08 15:39:01 morsch
19 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
21 Revision 1.20 2000/09/06 14:35:44 morsch
22 Use AliDecayerPythia for particle decays.
24 Revision 1.19 2000/07/11 18:24:56 fca
25 Coding convention corrections + few minor bug fixes
27 Revision 1.18 2000/06/29 21:08:27 morsch
28 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
29 This allows to pass a pointer to a library directly to AliGenParam and avoids the
30 use of function pointers in Config.C.
32 Revision 1.17 2000/06/09 20:33:30 morsch
33 All coding rule violations except RS3 corrected
35 Revision 1.16 2000/05/02 07:51:31 morsch
36 - Control precision of pT sampling TF1::SetNpx(..)
37 - Correct initialisation of child-cuts in all constructors.
38 - Most coding rule violations corrected.
40 Revision 1.15 2000/04/03 15:42:12 morsch
41 Cuts on primary particles are separated from those on the decay products. Methods
42 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
44 Revision 1.14 1999/11/09 07:38:48 fca
45 Changes for compatibility with version 2.23 of ROOT
47 Revision 1.13 1999/11/04 11:30:31 fca
48 Correct the logics for SetForceDecay
50 Revision 1.12 1999/11/03 17:43:20 fca
51 New version from G.Martinez & A.Morsch
53 Revision 1.11 1999/09/29 09:24:14 fca
54 Introduction of the Copyright and cvs Log
58 #include "AliGenParam.h"
59 #include "AliDecayerPythia.h"
60 #include "AliGenMUONlib.h"
62 #include "AliPythia.h"
63 #include <TParticle.h>
64 #include <TParticlePDG.h>
65 #include <TDatabasePDG.h>
66 #include <TLorentzVector.h>
72 //------------------------------------------------------------
76 <img src="picts/AliGenParam.gif">
80 //____________________________________________________________
81 //____________________________________________________________
82 AliGenParam::AliGenParam()
85 // Deafault constructor
91 SetChildMomentumRange();
98 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
100 // Constructor using number of particles parameterisation id and library
102 fPtParaFunc = Library->GetPt(param, tname);
103 fYParaFunc = Library->GetY (param, tname);
104 fIpParaFunc = Library->GetIp(param, tname);
111 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
114 SetChildMomentumRange();
117 SetChildThetaRange();
121 //____________________________________________________________
123 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
125 // Constructor using parameterisation id and number of particles
127 AliGenLib* Library = new AliGenMUONlib();
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();
148 AliGenParam::AliGenParam(Int_t npart, Param_t param,
149 Double_t (*PtPara) (Double_t*, Double_t*),
150 Double_t (*YPara ) (Double_t* ,Double_t*),
155 // Gines Martinez 1/10/99
156 fPtParaFunc = PtPara;
158 fIpParaFunc = IpPara;
165 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
168 SetChildMomentumRange();
171 SetChildThetaRange();
176 AliGenParam::AliGenParam(const AliGenParam & Paramd)
181 //____________________________________________________________
182 AliGenParam::~AliGenParam()
189 //____________________________________________________________
190 void AliGenParam::Init()
194 fDecayer = new AliDecayerPythia();
197 <img src="picts/AliGenParam.gif">
201 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
202 // Set representation precision to 10 MeV
203 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
205 fPtPara->SetNpx(npx);
207 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
208 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
209 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
216 fdNdy0=fYParaFunc(&y1,&y2);
218 // Integral over generation region
219 Float_t intYS = yPara ->Integral(fYMin, fYMax);
220 Float_t intPt0 = ptPara->Integral(0,15);
221 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
222 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
223 if (fAnalog == analog) {
224 fYWgt = intYS/fdNdy0;
225 fPtWgt = intPtS/intPt0;
226 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
228 fYWgt = intYS/fdNdy0;
229 fPtWgt = (fPtMax-fPtMin)/intPt0;
230 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
233 // particle decay related initialization
234 fDecayer->SetForceDecay(fForceDecay);
242 case b_jpsi_dielectron:
243 case b_psip_dielectron:
265 //____________________________________________________________
266 void AliGenParam::Generate()
269 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
270 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
271 // antineutrons in the the desired theta, phi and momentum windows;
272 // Gaussian smearing on the vertex is done if selected.
273 // The decay of heavy mesons is done using lujet,
274 // and the childern particle are tracked by GEANT
275 // However, light mesons are directly tracked by GEANT
276 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
279 fDecayer->ForceDecay();
280 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
281 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
282 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
283 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
285 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
287 Int_t nt, i, j, kfch[10];
290 static TClonesArray *particles;
292 if(!particles) particles=new TClonesArray("TParticle",1000);
294 static TDatabasePDG *DataBase = new TDatabasePDG();
295 if(!DataBase) DataBase = new TDatabasePDG();
299 // Calculating vertex position per event
300 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
301 if(fVertexSmear==kPerEvent) {
304 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
305 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
309 // Generating fNpart particles
314 Int_t iPart = fIpParaFunc();
315 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
316 TParticlePDG *particle = DataBase->GetParticle(iPart);
317 Float_t am = particle->Mass();
322 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
325 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
328 if (fAnalog == analog) {
329 pt=fPtPara->GetRandom();
333 pt=fPtMin+random[1]*(fPtMax-fPtMin);
335 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
336 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
338 xmt=sqrt(pt*pt+am*am);
339 pl=xmt*ty/sqrt(1.-ty*ty);
340 theta=TMath::ATan2(pt,pl);
342 if(theta<fThetaMin || theta>fThetaMax) continue;
343 ptot=TMath::Sqrt(pt*pt+pl*pl);
345 if(ptot<fPMin || ptot>fPMax) continue;
346 p[0]=pt*TMath::Cos(phi);
347 p[1]=pt*TMath::Sin(phi);
349 if(fVertexSmear==kPerTrack) {
353 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
354 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
358 // Looking at fForceDecay :
359 // if fForceDecay != none Primary particle decays using
360 // AliPythia and children are tracked by GEANT
362 // if fForceDecay == none Primary particle is tracked by GEANT
363 // (In the latest, make sure that GEANT actually does all the decays you want)
365 if (fForceDecay != nodecay) {
366 // Using lujet to decay particle
367 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
368 TLorentzVector pmom(p[0], p[1], p[2], energy);
369 fDecayer->Decay(iPart,&pmom);
371 // select decay particles
372 Int_t np=fDecayer->ImportParticles(particles);
374 for (i = 1; i<np; i++) {
375 TParticle * iparticle = (TParticle *) particles->At(i);
376 Int_t kf = iparticle->GetPdgCode();
379 if (ChildSelected(TMath::Abs(kf)) || fForceDecay==all)
381 pc[0]=iparticle->Px();
382 pc[1]=iparticle->Py();
383 pc[2]=iparticle->Pz();
384 och[0]=origin0[0]+iparticle->Vx()/10;
385 och[1]=origin0[1]+iparticle->Vy()/10;
386 och[2]=origin0[2]+iparticle->Vz()/10;
388 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
389 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
390 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
391 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
393 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
394 (pChild > fChildPMin && pChild <fChildPMax) &&
395 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
396 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
414 } // if child selection
416 } // decay particle loop
418 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
423 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
425 gAlice->KeepTrack(nt);
426 for (i=0; i< ncsel; i++) {
427 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
428 &pch[i][0],och,polar,
430 gAlice->KeepTrack(nt);
433 } // kinematic selection
434 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
437 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
445 Bool_t AliGenParam::ChildSelected(Int_t ip)
447 // True if particle is in list of selected children
448 for (Int_t i=0; i<5; i++)
450 if (fChildSelect[i]==ip) return kTRUE;
455 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
457 // Perform kinematic cuts
458 Float_t px=particle->Px();
459 Float_t py=particle->Py();
460 Float_t pz=particle->Pz();
463 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
464 if (p > fPMax || p < fPMin)
466 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
469 Float_t pt=TMath::Sqrt(px*px+py*py);
473 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
474 if (theta > fThetaMax || theta < fThetaMin)
476 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
484 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
486 // Assignment operator