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 1.24 2000/10/18 19:11:27 hristov
19 Division by zero fixed
21 Revision 1.23 2000/10/02 21:28:06 fca
22 Removal of useless dependecies via forward declarations
24 Revision 1.22 2000/09/12 14:14:55 morsch
25 Call fDecayer->ForceDecay() at the beginning of Generate().
27 Revision 1.21 2000/09/08 15:39:01 morsch
28 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
30 Revision 1.20 2000/09/06 14:35:44 morsch
31 Use AliDecayerPythia for particle decays.
33 Revision 1.19 2000/07/11 18:24:56 fca
34 Coding convention corrections + few minor bug fixes
36 Revision 1.18 2000/06/29 21:08:27 morsch
37 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
38 This allows to pass a pointer to a library directly to AliGenParam and avoids the
39 use of function pointers in Config.C.
41 Revision 1.17 2000/06/09 20:33:30 morsch
42 All coding rule violations except RS3 corrected
44 Revision 1.16 2000/05/02 07:51:31 morsch
45 - Control precision of pT sampling TF1::SetNpx(..)
46 - Correct initialisation of child-cuts in all constructors.
47 - Most coding rule violations corrected.
49 Revision 1.15 2000/04/03 15:42:12 morsch
50 Cuts on primary particles are separated from those on the decay products. Methods
51 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
53 Revision 1.14 1999/11/09 07:38:48 fca
54 Changes for compatibility with version 2.23 of ROOT
56 Revision 1.13 1999/11/04 11:30:31 fca
57 Correct the logics for SetForceDecay
59 Revision 1.12 1999/11/03 17:43:20 fca
60 New version from G.Martinez & A.Morsch
62 Revision 1.11 1999/09/29 09:24:14 fca
63 Introduction of the Copyright and cvs Log
67 #include "AliGenParam.h"
68 #include "AliDecayerPythia.h"
69 #include "AliGenMUONlib.h"
71 #include <TParticle.h>
72 #include <TParticlePDG.h>
73 #include <TDatabasePDG.h>
74 #include <TLorentzVector.h>
80 //------------------------------------------------------------
84 <img src="picts/AliGenParam.gif">
88 //____________________________________________________________
89 //____________________________________________________________
90 AliGenParam::AliGenParam()
92 // Deafault constructor
98 SetChildMomentumRange();
101 SetChildThetaRange();
105 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
107 // Constructor using number of particles parameterisation id and library
109 fPtParaFunc = Library->GetPt(param, tname);
110 fYParaFunc = Library->GetY (param, tname);
111 fIpParaFunc = Library->GetIp(param, tname);
118 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
121 SetChildMomentumRange();
124 SetChildThetaRange();
128 //____________________________________________________________
130 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
132 // Constructor using parameterisation id and number of particles
134 AliGenLib* Library = new AliGenMUONlib();
136 fPtParaFunc = Library->GetPt(param, tname);
137 fYParaFunc = Library->GetY (param, tname);
138 fIpParaFunc = Library->GetIp(param, tname);
145 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
148 SetChildMomentumRange();
151 SetChildThetaRange();
155 AliGenParam::AliGenParam(Int_t npart, Param_t param,
156 Double_t (*PtPara) (Double_t*, Double_t*),
157 Double_t (*YPara ) (Double_t* ,Double_t*),
158 Int_t (*IpPara) (TRandom *))
162 // Gines Martinez 1/10/99
163 fPtParaFunc = PtPara;
165 fIpParaFunc = IpPara;
172 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
175 SetChildMomentumRange();
178 SetChildThetaRange();
183 AliGenParam::AliGenParam(const AliGenParam & Paramd)
188 //____________________________________________________________
189 AliGenParam::~AliGenParam()
196 //____________________________________________________________
197 void AliGenParam::Init()
201 fDecayer = new AliDecayerPythia();
204 <img src="picts/AliGenParam.gif">
208 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
209 // Set representation precision to 10 MeV
210 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
212 fPtPara->SetNpx(npx);
214 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
215 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
216 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
223 fdNdy0=fYParaFunc(&y1,&y2);
225 // Integral over generation region
226 Float_t intYS = yPara ->Integral(fYMin, fYMax);
227 Float_t intPt0 = ptPara->Integral(0,15);
228 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
229 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
230 if (fAnalog == analog) {
231 fYWgt = intYS/fdNdy0;
232 fPtWgt = intPtS/intPt0;
233 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
235 fYWgt = intYS/fdNdy0;
236 fPtWgt = (fPtMax-fPtMin)/intPt0;
237 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
240 // particle decay related initialization
241 fDecayer->SetForceDecay(fForceDecay);
249 case b_jpsi_dielectron:
250 case b_psip_dielectron:
272 //____________________________________________________________
273 void AliGenParam::Generate()
276 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
277 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
278 // antineutrons in the the desired theta, phi and momentum windows;
279 // Gaussian smearing on the vertex is done if selected.
280 // The decay of heavy mesons is done using lujet,
281 // and the childern particle are tracked by GEANT
282 // However, light mesons are directly tracked by GEANT
283 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
286 fDecayer->ForceDecay();
287 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
288 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
289 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
290 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
292 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
294 Int_t nt, i, j, kfch[10];
297 static TClonesArray *particles;
299 if(!particles) particles=new TClonesArray("TParticle",1000);
301 static TDatabasePDG *DataBase = new TDatabasePDG();
302 if(!DataBase) DataBase = new TDatabasePDG();
306 // Calculating vertex position per event
307 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
308 if(fVertexSmear==kPerEvent) {
311 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
312 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
316 // Generating fNpart particles
321 Int_t iPart = fIpParaFunc(fRandom);
322 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
323 TParticlePDG *particle = DataBase->GetParticle(iPart);
324 Float_t am = particle->Mass();
329 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
332 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
335 if (fAnalog == analog) {
336 pt=fPtPara->GetRandom();
340 pt=fPtMin+random[1]*(fPtMax-fPtMin);
342 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
343 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
345 xmt=sqrt(pt*pt+am*am);
346 if (TMath::Abs(ty)==1) ty=0;
347 pl=xmt*ty/sqrt(1.-ty*ty);
348 theta=TMath::ATan2(pt,pl);
350 if(theta<fThetaMin || theta>fThetaMax) continue;
351 ptot=TMath::Sqrt(pt*pt+pl*pl);
353 if(ptot<fPMin || ptot>fPMax) continue;
354 p[0]=pt*TMath::Cos(phi);
355 p[1]=pt*TMath::Sin(phi);
357 if(fVertexSmear==kPerTrack) {
361 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
362 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
366 // Looking at fForceDecay :
367 // if fForceDecay != none Primary particle decays using
368 // AliPythia and children are tracked by GEANT
370 // if fForceDecay == none Primary particle is tracked by GEANT
371 // (In the latest, make sure that GEANT actually does all the decays you want)
373 if (fForceDecay != nodecay) {
374 // Using lujet to decay particle
375 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
376 TLorentzVector pmom(p[0], p[1], p[2], energy);
377 fDecayer->Decay(iPart,&pmom);
379 // select decay particles
380 Int_t np=fDecayer->ImportParticles(particles);
382 for (i = 1; i<np; i++) {
383 TParticle * iparticle = (TParticle *) particles->At(i);
384 Int_t kf = iparticle->GetPdgCode();
387 if (ChildSelected(TMath::Abs(kf)) || fForceDecay==all)
389 pc[0]=iparticle->Px();
390 pc[1]=iparticle->Py();
391 pc[2]=iparticle->Pz();
392 och[0]=origin0[0]+iparticle->Vx()/10;
393 och[1]=origin0[1]+iparticle->Vy()/10;
394 och[2]=origin0[2]+iparticle->Vz()/10;
396 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
397 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
398 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
399 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
401 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
402 (pChild > fChildPMin && pChild <fChildPMax) &&
403 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
404 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
422 } // if child selection
424 } // decay particle loop
426 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
431 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
433 gAlice->KeepTrack(nt);
434 for (i=0; i< ncsel; i++) {
435 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
436 &pch[i][0],och,polar,
438 gAlice->KeepTrack(nt);
441 } // kinematic selection
442 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
445 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
453 Bool_t AliGenParam::ChildSelected(Int_t ip)
455 // True if particle is in list of selected children
456 for (Int_t i=0; i<5; i++)
458 if (fChildSelect[i]==ip) return kTRUE;
463 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
465 // Perform kinematic cuts
466 Float_t px=particle->Px();
467 Float_t py=particle->Py();
468 Float_t pz=particle->Pz();
471 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
472 if (p > fPMax || p < fPMin)
474 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
477 Float_t pt=TMath::Sqrt(px*px+py*py);
481 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
482 if (theta > fThetaMax || theta < fThetaMin)
484 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
492 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
494 // Assignment operator