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 1.19 2000/07/11 18:24:56 fca
19 Coding convention corrections + few minor bug fixes
21 Revision 1.18 2000/06/29 21:08:27 morsch
22 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
23 This allows to pass a pointer to a library directly to AliGenParam and avoids the
24 use of function pointers in Config.C.
26 Revision 1.17 2000/06/09 20:33:30 morsch
27 All coding rule violations except RS3 corrected
29 Revision 1.16 2000/05/02 07:51:31 morsch
30 - Control precision of pT sampling TF1::SetNpx(..)
31 - Correct initialisation of child-cuts in all constructors.
32 - Most coding rule violations corrected.
34 Revision 1.15 2000/04/03 15:42:12 morsch
35 Cuts on primary particles are separated from those on the decay products. Methods
36 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
38 Revision 1.14 1999/11/09 07:38:48 fca
39 Changes for compatibility with version 2.23 of ROOT
41 Revision 1.13 1999/11/04 11:30:31 fca
42 Correct the logics for SetForceDecay
44 Revision 1.12 1999/11/03 17:43:20 fca
45 New version from G.Martinez & A.Morsch
47 Revision 1.11 1999/09/29 09:24:14 fca
48 Introduction of the Copyright and cvs Log
52 #include "AliGenParam.h"
53 #include "AliDecayerPythia.h"
54 #include "AliGenMUONlib.h"
56 #include "AliPythia.h"
57 #include <TParticle.h>
58 #include <TParticlePDG.h>
59 #include <TDatabasePDG.h>
60 #include <TLorentzVector.h>
66 //------------------------------------------------------------
70 <img src="picts/AliGenParam.gif">
74 //____________________________________________________________
75 //____________________________________________________________
76 AliGenParam::AliGenParam()
79 // Deafault constructor
85 SetChildMomentumRange();
92 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
94 // Constructor using number of particles parameterisation id and library
96 fPtParaFunc = Library->GetPt(param, tname);
97 fYParaFunc = Library->GetY (param, tname);
98 fIpParaFunc = Library->GetIp(param, tname);
105 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
108 SetChildMomentumRange();
111 SetChildThetaRange();
115 //____________________________________________________________
117 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
119 // Constructor using parameterisation id and number of particles
121 AliGenLib* Library = new AliGenMUONlib();
123 fPtParaFunc = Library->GetPt(param, tname);
124 fYParaFunc = Library->GetY (param, tname);
125 fIpParaFunc = Library->GetIp(param, tname);
132 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
135 SetChildMomentumRange();
138 SetChildThetaRange();
142 AliGenParam::AliGenParam(Int_t npart, Param_t param,
143 Double_t (*PtPara) (Double_t*, Double_t*),
144 Double_t (*YPara ) (Double_t* ,Double_t*),
149 // Gines Martinez 1/10/99
150 fPtParaFunc = PtPara;
152 fIpParaFunc = IpPara;
159 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
162 SetChildMomentumRange();
165 SetChildThetaRange();
170 AliGenParam::AliGenParam(const AliGenParam & Paramd)
175 //____________________________________________________________
176 AliGenParam::~AliGenParam()
183 //____________________________________________________________
184 void AliGenParam::Init()
188 fDecayer = new AliDecayerPythia();
191 <img src="picts/AliGenParam.gif">
195 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
196 // Set representation precision to 10 MeV
197 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
199 fPtPara->SetNpx(npx);
201 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
202 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
203 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
210 fdNdy0=fYParaFunc(&y1,&y2);
212 // Integral over generation region
213 Float_t intYS = yPara ->Integral(fYMin, fYMax);
214 Float_t intPt0 = ptPara->Integral(0,15);
215 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
216 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
217 if (fAnalog == analog) {
218 fYWgt = intYS/fdNdy0;
219 fPtWgt = intPtS/intPt0;
220 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
222 fYWgt = intYS/fdNdy0;
223 fPtWgt = (fPtMax-fPtMin)/intPt0;
224 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
227 // particle decay related initialization
229 // semimuonic decays of charm and beauty
230 fDecayer->ForceDecay(fForceDecay);
236 case b_jpsi_dielectron:
237 case b_psip_dielectron:
259 //____________________________________________________________
260 void AliGenParam::Generate()
263 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
264 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
265 // antineutrons in the the desired theta, phi and momentum windows;
266 // Gaussian smearing on the vertex is done if selected.
267 // The decay of heavy mesons is done using lujet,
268 // and the childern particle are tracked by GEANT
269 // However, light mesons are directly tracked by GEANT
270 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
274 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
275 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
276 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
277 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
279 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
281 Int_t nt, i, j, kfch[10];
284 static TClonesArray *particles;
286 if(!particles) particles=new TClonesArray("TParticle",1000);
288 static TDatabasePDG *DataBase = new TDatabasePDG();
289 if(!DataBase) DataBase = new TDatabasePDG();
293 // Calculating vertex position per event
294 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
295 if(fVertexSmear==kPerEvent) {
298 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
299 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
303 // Generating fNpart particles
308 Int_t iPart = fIpParaFunc();
309 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
310 TParticlePDG *particle = DataBase->GetParticle(iPart);
311 Float_t am = particle->Mass();
316 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
319 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
322 if (fAnalog == analog) {
323 pt=fPtPara->GetRandom();
327 pt=fPtMin+random[1]*(fPtMax-fPtMin);
329 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
330 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
332 xmt=sqrt(pt*pt+am*am);
333 pl=xmt*ty/sqrt(1.-ty*ty);
334 theta=TMath::ATan2(pt,pl);
336 if(theta<fThetaMin || theta>fThetaMax) continue;
337 ptot=TMath::Sqrt(pt*pt+pl*pl);
339 if(ptot<fPMin || ptot>fPMax) continue;
340 p[0]=pt*TMath::Cos(phi);
341 p[1]=pt*TMath::Sin(phi);
343 if(fVertexSmear==kPerTrack) {
347 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
348 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
352 // Looking at fForceDecay :
353 // if fForceDecay != none Primary particle decays using
354 // AliPythia and children are tracked by GEANT
356 // if fForceDecay == none Primary particle is tracked by GEANT
357 // (In the latest, make sure that GEANT actually does all the decays you want)
359 if (fForceDecay != nodecay) {
360 // Using lujet to decay particle
361 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
362 TLorentzVector pmom(p[0], p[1], p[2], energy);
363 fDecayer->Decay(iPart,&pmom);
365 // select decay particles
366 Int_t np=fDecayer->ImportParticles(particles);
368 for (i = 1; i<np; i++) {
369 TParticle * iparticle = (TParticle *) particles->At(i);
370 Int_t kf = iparticle->GetPdgCode();
373 if (ChildSelected(TMath::Abs(kf)))
375 pc[0]=iparticle->Px();
376 pc[1]=iparticle->Py();
377 pc[2]=iparticle->Pz();
378 och[0]=origin0[0]+iparticle->Vx()/10;
379 och[1]=origin0[1]+iparticle->Vy()/10;
380 och[2]=origin0[2]+iparticle->Vz()/10;
382 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
383 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
384 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
385 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
387 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
388 (pChild > fChildPMin && pChild <fChildPMax) &&
389 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
390 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
408 } // if child selection
410 } // decay particle loop
412 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
417 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
419 gAlice->KeepTrack(nt);
420 for (i=0; i< ncsel; i++) {
421 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
422 &pch[i][0],och,polar,
424 gAlice->KeepTrack(nt);
427 } // kinematic selection
428 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
431 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
439 Bool_t AliGenParam::ChildSelected(Int_t ip)
441 // True if particle is in list of selected children
442 for (Int_t i=0; i<5; i++)
444 if (fChildSelect[i]==ip) return kTRUE;
449 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
451 // Perform kinematic cuts
452 Float_t px=particle->Px();
453 Float_t py=particle->Py();
454 Float_t pz=particle->Pz();
457 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
458 if (p > fPMax || p < fPMin)
460 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
463 Float_t pt=TMath::Sqrt(px*px+py*py);
467 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
468 if (theta > fThetaMax || theta < fThetaMin)
470 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
478 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
480 // Assignment operator