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 1.16 2000/05/02 07:51:31 morsch
19 - Control precision of pT sampling TF1::SetNpx(..)
20 - Correct initialisation of child-cuts in all constructors.
21 - Most coding rule violations corrected.
23 Revision 1.15 2000/04/03 15:42:12 morsch
24 Cuts on primary particles are separated from those on the decay products. Methods
25 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
27 Revision 1.14 1999/11/09 07:38:48 fca
28 Changes for compatibility with version 2.23 of ROOT
30 Revision 1.13 1999/11/04 11:30:31 fca
31 Correct the logics for SetForceDecay
33 Revision 1.12 1999/11/03 17:43:20 fca
34 New version from G.Martinez & A.Morsch
36 Revision 1.11 1999/09/29 09:24:14 fca
37 Introduction of the Copyright and cvs Log
41 #include "AliGenParam.h"
42 #include "AliGenMUONlib.h"
44 #include "AliPythia.h"
45 #include <TParticle.h>
50 //------------------------------------------------------------
54 <img src="picts/AliGenParam.gif">
58 //____________________________________________________________
59 //____________________________________________________________
60 AliGenParam::AliGenParam()
69 SetChildMomentumRange();
76 //____________________________________________________________
78 AliGenParam::AliGenParam(Int_t npart, Param_t param) :AliGenerator(npart)
82 // fName="HMESONpara";
83 // fTitle="Heavy Mesons Parametrisation";
84 fPtParaFunc = AliGenMUONlib::GetPt(param);
85 fYParaFunc = AliGenMUONlib::GetY(param);
86 fIpParaFunc = AliGenMUONlib::GetIp(param);
93 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
96 SetChildMomentumRange();
103 AliGenParam::AliGenParam(Int_t npart, Param_t param,
104 Double_t (*PtPara) (Double_t*, Double_t*),
105 Double_t (*YPara ) (Double_t* ,Double_t*),
110 // Gines Martinez 1/10/99
111 fPtParaFunc = PtPara;
113 fIpParaFunc = IpPara;
120 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
123 SetChildMomentumRange();
126 SetChildThetaRange();
131 AliGenParam::AliGenParam(const AliGenParam & Paramd)
136 //____________________________________________________________
137 AliGenParam::~AliGenParam()
144 //____________________________________________________________
145 void AliGenParam::Init()
148 SetMC(new AliPythia());
149 fPythia= (AliPythia*) fgMCEvGen;
153 <img src="picts/AliGenParam.gif">
157 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
158 // Set representation precision to 10 MeV
159 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
161 fPtPara->SetNpx(npx);
163 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
164 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
165 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
172 fdNdy0=fYParaFunc(&y1,&y2);
174 // Integral over generation region
175 Float_t intYS = yPara ->Integral(fYMin, fYMax);
176 Float_t intPt0 = ptPara->Integral(0,15);
177 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
178 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
179 if (fAnalog == analog) {
180 fYWgt = intYS/fdNdy0;
181 fPtWgt = intPtS/intPt0;
182 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
184 fYWgt = intYS/fdNdy0;
185 fPtWgt = (fPtMax-fPtMin)/intPt0;
186 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
189 // particle decay related initialization
190 fPythia->DefineParticles();
191 // semimuonic decays of charm and beauty
192 fPythia->ForceDecay(fForceDecay);
198 case b_jpsi_dielectron:
199 case b_psip_dielectron:
221 //____________________________________________________________
222 void AliGenParam::Generate()
225 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
226 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
227 // antineutrons in the the desired theta, phi and momentum windows;
228 // Gaussian smearing on the vertex is done if selected.
229 // The decay of heavy mesons is done using lujet,
230 // and the childern particle are tracked by GEANT
231 // However, light mesons are directly tracked by GEANT
232 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
236 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
237 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
238 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
239 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
241 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
243 Int_t nt, i, j, kfch[10];
246 static TClonesArray *particles;
248 if(!particles) particles=new TClonesArray("TParticle",1000);
252 // Calculating vertex position per event
253 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
254 if(fVertexSmear==perEvent) {
257 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
258 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
262 // Generating fNpart particles
267 Int_t iPart = fIpParaFunc();
268 fChildWeight=(fPythia->GetBraPart(iPart))*fParentWeight;
269 Float_t am=fPythia->GetPMAS(fPythia->Lucomp(iPart),1);
273 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
276 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
279 if (fAnalog == analog) {
280 pt=fPtPara->GetRandom();
284 pt=fPtMin+random[1]*(fPtMax-fPtMin);
286 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
287 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
289 xmt=sqrt(pt*pt+am*am);
290 pl=xmt*ty/sqrt(1.-ty*ty);
291 theta=TMath::ATan2(pt,pl);
293 if(theta<fThetaMin || theta>fThetaMax) continue;
294 ptot=TMath::Sqrt(pt*pt+pl*pl);
296 if(ptot<fPMin || ptot>fPMax) continue;
297 p[0]=pt*TMath::Cos(phi);
298 p[1]=pt*TMath::Sin(phi);
300 if(fVertexSmear==perTrack) {
304 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
305 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
309 // Looking at fForceDecay :
310 // if fForceDecay != none Primary particle decays using
311 // AliPythia and children are tracked by GEANT
313 // if fForceDecay == none Primary particle is tracked by GEANT
314 // (In the latest, make sure that GEANT actually does all the decays you want)
316 if (fForceDecay != nodecay) {
317 // Using lujet to decay particle
318 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
319 fPythia->DecayParticle(iPart,energy,theta,phi);
321 // select decay particles
322 Int_t np=fPythia->ImportParticles(particles,"All");
324 for (i = 1; i<np; i++) {
325 TParticle * iparticle = (TParticle *) particles->At(i);
326 Int_t kf = iparticle->GetPdgCode();
329 if (ChildSelected(TMath::Abs(kf)))
331 pc[0]=iparticle->Px();
332 pc[1]=iparticle->Py();
333 pc[2]=iparticle->Pz();
334 och[0]=origin0[0]+iparticle->Vx()/10;
335 och[1]=origin0[1]+iparticle->Vy()/10;
336 och[2]=origin0[2]+iparticle->Vz()/10;
338 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
339 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
340 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
341 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
343 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
344 (pChild > fChildPMin && pChild <fChildPMax) &&
345 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
346 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
364 } // if child selection
366 } // decay particle loop
368 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
373 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
375 gAlice->KeepTrack(nt);
376 for (i=0; i< ncsel; i++) {
377 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
378 &pch[i][0],och,polar,
380 gAlice->KeepTrack(nt);
383 } // kinematic selection
384 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
387 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
395 Bool_t AliGenParam::ChildSelected(Int_t ip)
397 // True if particle is in list of selected children
398 for (Int_t i=0; i<5; i++)
400 if (fChildSelect[i]==ip) return kTRUE;
405 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
407 // Perform kinematic cuts
408 Float_t px=particle->Px();
409 Float_t py=particle->Py();
410 Float_t pz=particle->Pz();
413 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
414 if (p > fPMax || p < fPMin)
416 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
419 Float_t pt=TMath::Sqrt(px*px+py*py);
423 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
424 if (theta > fThetaMax || theta < fThetaMin)
426 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
434 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
436 // Assignment operator