1 #include "AliGenParam.h"
2 #include "AliGenMUONlib.h"
6 #include <TDirectory.h>
10 #include <TMCParticle.h>
14 //------------------------------------------------------------
18 <img src="gif/AliGenParam.gif">
22 //____________________________________________________________
23 //____________________________________________________________
24 AliGenParam::AliGenParam()
33 //____________________________________________________________
34 AliGenParam::AliGenParam(Int_t npart, Param_t param)
35 // Double_t (*PtPara)(Double_t*, Double_t*),
36 // Double_t (*YPara) (Double_t* ,Double_t*))
40 // fName="HMESONpara";
41 // fTitle="Heavy Mesons Parametrisation";
42 fPtParaFunc = AliGenMUONlib::GetPt(param);
43 fYParaFunc = AliGenMUONlib::GetY(param);
44 fIpParaFunc = AliGenMUONlib::GetIp(param);
51 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
55 //____________________________________________________________
56 AliGenParam::~AliGenParam()
62 //____________________________________________________________
63 void AliGenParam::Init()
65 SetMC(new AliPythia());
66 fPythia= (AliPythia*) fgMCEvGen;
68 // End of the test !!!
71 <img src="gif/AliGenParam.gif">
75 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
76 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
77 TF1* PtPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
78 TF1* YPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
85 fdNdy0=fYParaFunc(&y1,&y2);
87 // Integral over generation region
88 Float_t IntYS = YPara ->Integral(fYMin, fYMax);
89 Float_t IntPt0 = PtPara->Integral(0,15);
90 Float_t IntPtS = PtPara->Integral(fPtMin,fPtMax);
91 Float_t PhiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
94 fPtWgt = IntPtS/IntPt0;
95 fParentWeight = fYWgt*fPtWgt*PhiWgt/fNpart;
98 fPtWgt = (fPtMax-fPtMin)/IntPt0;
99 fParentWeight = fYWgt*fPtWgt*PhiWgt/fNpart;
102 // particle decay related initialization
103 fPythia->DefineParticles();
104 // semimuonic decays of charm and beauty
105 fPythia->ForceDecay(fForceDecay);
111 case b_jpsi_dielectron:
112 case b_psip_dielectron:
131 //____________________________________________________________
132 void AliGenParam::Generate()
134 // Generate 'npart' of heavy mesons (J/Psi, upsilon or phi) in the
135 // the desired theta, phi and momentum windows; Gaussian smearing
136 // on the vertex is done if selected
138 AliMC* pMC = AliMC::GetMC();
140 Float_t polar[3]= {0,0,0};
142 Float_t origin[3], origin0[3];
143 Float_t pt, pl, ptot;
153 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
154 if(fVertexSmear==perEvent) {
157 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
158 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
161 for(i=0;i<fNpart;i++) {
165 Int_t Ipart = fIpParaFunc();
166 fChildWeight=(fPythia->GetBraPart(Ipart))*fParentWeight;
167 Float_t am=fPythia->GetPMAS(fPythia->LuComp(Ipart),1);
171 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
174 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
178 pt=fPtPara->GetRandom();
182 pt=fPtMin+random[1]*(fPtMax-fPtMin);
184 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
185 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
187 xmt=sqrt(pt*pt+am*am);
188 pl=xmt*ty/sqrt(1.-ty*ty);
189 theta=TMath::ATan2(pt,pl);
190 if(theta<fThetaMin || theta>fThetaMax) continue;
191 ptot=TMath::Sqrt(pt*pt+pl*pl);
192 if(ptot<fPMin || ptot>fPMax) continue;
193 p[0]=pt*TMath::Cos(phi);
194 p[1]=pt*TMath::Sin(phi);
196 if(fVertexSmear==perTrack) {
200 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
201 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
205 Int_t kg=fPythia->GetGeantCode(Ipart);
210 SetTrack(0,-1,kg,p,origin,polar,0,"Primary",nt,wgtp);
213 // use lujet to decay particle
215 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
216 fPythia->DecayParticle(Ipart,energy,theta,phi);
217 // fPythia->LuList(1);
221 TObjArray* particles = fPythia->GetPrimaries() ;
222 Int_t np = particles->GetEntriesFast();
223 for (Int_t i = 0; i<np; i++) {
224 TMCParticle * iparticle = (TMCParticle *) particles->At(i);
225 Int_t kf = iparticle->GetKF();
228 if (ChildSelected(TMath::Abs(kf)))
230 p[0]=iparticle->GetPx();
231 p[1]=iparticle->GetPy();
232 p[2]=iparticle->GetPz();
233 origin[0]=origin0[0]+iparticle->GetVx()/10;
234 origin[1]=origin0[1]+iparticle->GetVy()/10;
235 origin[2]=origin0[2]+iparticle->GetVz()/10;
236 gAlice->SetTrack(fTrackIt,iparent,fPythia->GetGeantCode(kf),
239 gAlice->KeepTrack(nt);
241 } // decay particle loop
243 } // kinematic selection
247 Bool_t AliGenParam::ChildSelected(Int_t ip)
249 for (Int_t i=0; i<5; i++)
251 if (fChildSelect[i]==ip) return kTRUE;
256 Bool_t AliGenParam::KinematicSelection(TMCParticle *particle)
258 Float_t px=particle->GetPx();
259 Float_t py=particle->GetPy();
260 Float_t pz=particle->GetPz();
263 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
264 if (p > fPMax || p < fPMin)
266 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
269 Float_t pt=TMath::Sqrt(px*px+py*py);
273 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
274 if (theta > fThetaMax || theta < fThetaMin)
276 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);