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 1.17 2000/06/09 20:33:30 morsch
19 All coding rule violations except RS3 corrected
21 Revision 1.16 2000/05/02 07:51:31 morsch
22 - Control precision of pT sampling TF1::SetNpx(..)
23 - Correct initialisation of child-cuts in all constructors.
24 - Most coding rule violations corrected.
26 Revision 1.15 2000/04/03 15:42:12 morsch
27 Cuts on primary particles are separated from those on the decay products. Methods
28 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
30 Revision 1.14 1999/11/09 07:38:48 fca
31 Changes for compatibility with version 2.23 of ROOT
33 Revision 1.13 1999/11/04 11:30:31 fca
34 Correct the logics for SetForceDecay
36 Revision 1.12 1999/11/03 17:43:20 fca
37 New version from G.Martinez & A.Morsch
39 Revision 1.11 1999/09/29 09:24:14 fca
40 Introduction of the Copyright and cvs Log
44 #include "AliGenParam.h"
45 #include "AliGenMUONlib.h"
47 #include "AliPythia.h"
48 #include <TParticle.h>
53 //------------------------------------------------------------
57 <img src="picts/AliGenParam.gif">
61 //____________________________________________________________
62 //____________________________________________________________
63 AliGenParam::AliGenParam()
66 // Deafault constructor
72 SetChildMomentumRange();
79 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
81 // Constructor using number of particles parameterisation id and library
83 fPtParaFunc = Library->GetPt(param, tname);
84 fYParaFunc = Library->GetY (param, tname);
85 fIpParaFunc = Library->GetIp(param, tname);
92 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
95 SetChildMomentumRange();
102 //____________________________________________________________
104 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
106 // Constructor using parameterisation id and number of particles
108 AliGenLib* Library = new AliGenMUONlib();
110 fPtParaFunc = Library->GetPt(param, tname);
111 fYParaFunc = Library->GetY (param, tname);
112 fIpParaFunc = Library->GetIp(param, tname);
119 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
122 SetChildMomentumRange();
125 SetChildThetaRange();
129 AliGenParam::AliGenParam(Int_t npart, Param_t param,
130 Double_t (*PtPara) (Double_t*, Double_t*),
131 Double_t (*YPara ) (Double_t* ,Double_t*),
136 // Gines Martinez 1/10/99
137 fPtParaFunc = PtPara;
139 fIpParaFunc = IpPara;
146 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
149 SetChildMomentumRange();
152 SetChildThetaRange();
157 AliGenParam::AliGenParam(const AliGenParam & Paramd)
162 //____________________________________________________________
163 AliGenParam::~AliGenParam()
170 //____________________________________________________________
171 void AliGenParam::Init()
174 SetMC(new AliPythia());
175 fPythia= (AliPythia*) fgMCEvGen;
179 <img src="picts/AliGenParam.gif">
183 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
184 // Set representation precision to 10 MeV
185 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
187 fPtPara->SetNpx(npx);
189 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
190 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
191 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
198 fdNdy0=fYParaFunc(&y1,&y2);
200 // Integral over generation region
201 Float_t intYS = yPara ->Integral(fYMin, fYMax);
202 Float_t intPt0 = ptPara->Integral(0,15);
203 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
204 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
205 if (fAnalog == analog) {
206 fYWgt = intYS/fdNdy0;
207 fPtWgt = intPtS/intPt0;
208 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
210 fYWgt = intYS/fdNdy0;
211 fPtWgt = (fPtMax-fPtMin)/intPt0;
212 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
215 // particle decay related initialization
216 fPythia->DefineParticles();
217 // semimuonic decays of charm and beauty
218 fPythia->ForceDecay(fForceDecay);
224 case b_jpsi_dielectron:
225 case b_psip_dielectron:
247 //____________________________________________________________
248 void AliGenParam::Generate()
251 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
252 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
253 // antineutrons in the the desired theta, phi and momentum windows;
254 // Gaussian smearing on the vertex is done if selected.
255 // The decay of heavy mesons is done using lujet,
256 // and the childern particle are tracked by GEANT
257 // However, light mesons are directly tracked by GEANT
258 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
262 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
263 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
264 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
265 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
267 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
269 Int_t nt, i, j, kfch[10];
272 static TClonesArray *particles;
274 if(!particles) particles=new TClonesArray("TParticle",1000);
278 // Calculating vertex position per event
279 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
280 if(fVertexSmear==perEvent) {
283 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
284 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
288 // Generating fNpart particles
293 Int_t iPart = fIpParaFunc();
294 fChildWeight=(fPythia->GetBraPart(iPart))*fParentWeight;
295 Float_t am=fPythia->GetPMAS(fPythia->Lucomp(iPart),1);
299 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
302 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
305 if (fAnalog == analog) {
306 pt=fPtPara->GetRandom();
310 pt=fPtMin+random[1]*(fPtMax-fPtMin);
312 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
313 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
315 xmt=sqrt(pt*pt+am*am);
316 pl=xmt*ty/sqrt(1.-ty*ty);
317 theta=TMath::ATan2(pt,pl);
319 if(theta<fThetaMin || theta>fThetaMax) continue;
320 ptot=TMath::Sqrt(pt*pt+pl*pl);
322 if(ptot<fPMin || ptot>fPMax) continue;
323 p[0]=pt*TMath::Cos(phi);
324 p[1]=pt*TMath::Sin(phi);
326 if(fVertexSmear==perTrack) {
330 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
331 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
335 // Looking at fForceDecay :
336 // if fForceDecay != none Primary particle decays using
337 // AliPythia and children are tracked by GEANT
339 // if fForceDecay == none Primary particle is tracked by GEANT
340 // (In the latest, make sure that GEANT actually does all the decays you want)
342 if (fForceDecay != nodecay) {
343 // Using lujet to decay particle
344 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
345 fPythia->DecayParticle(iPart,energy,theta,phi);
347 // select decay particles
348 Int_t np=fPythia->ImportParticles(particles,"All");
350 for (i = 1; i<np; i++) {
351 TParticle * iparticle = (TParticle *) particles->At(i);
352 Int_t kf = iparticle->GetPdgCode();
355 if (ChildSelected(TMath::Abs(kf)))
357 pc[0]=iparticle->Px();
358 pc[1]=iparticle->Py();
359 pc[2]=iparticle->Pz();
360 och[0]=origin0[0]+iparticle->Vx()/10;
361 och[1]=origin0[1]+iparticle->Vy()/10;
362 och[2]=origin0[2]+iparticle->Vz()/10;
364 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
365 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
366 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
367 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
369 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
370 (pChild > fChildPMin && pChild <fChildPMax) &&
371 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
372 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
390 } // if child selection
392 } // decay particle loop
394 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
399 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
401 gAlice->KeepTrack(nt);
402 for (i=0; i< ncsel; i++) {
403 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
404 &pch[i][0],och,polar,
406 gAlice->KeepTrack(nt);
409 } // kinematic selection
410 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
413 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
421 Bool_t AliGenParam::ChildSelected(Int_t ip)
423 // True if particle is in list of selected children
424 for (Int_t i=0; i<5; i++)
426 if (fChildSelect[i]==ip) return kTRUE;
431 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
433 // Perform kinematic cuts
434 Float_t px=particle->Px();
435 Float_t py=particle->Py();
436 Float_t pz=particle->Pz();
439 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
440 if (p > fPMax || p < fPMin)
442 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
445 Float_t pt=TMath::Sqrt(px*px+py*py);
449 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
450 if (theta > fThetaMax || theta < fThetaMin)
452 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
460 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
462 // Assignment operator