2 #include "AliHLTD0toKpi.h"
3 #include "TDatabasePDG.h"
5 #include "AliESDtrack.h"
7 #include "AliAODVertex.h"
8 #include "AliESDVertex.h"
10 #include "AliVertexerTracks.h"
11 #include "AliHLTGlobalBarrelTrack.h"
12 #include "AliExternalTrackParam.h"
13 #include "AliKFVertex.h"
15 ClassImp(AliHLTD0toKpi)
17 AliHLTD0toKpi::AliHLTD0toKpi()
21 Double_t AliHLTD0toKpi::InvMass(AliExternalTrackParam* d1, AliExternalTrackParam* d2)
23 Double_t mpi=TDatabasePDG::Instance()->GetParticle(211)->Mass();
24 Double_t mK=TDatabasePDG::Instance()->GetParticle(321)->Mass();
27 energy[1] = TMath::Sqrt(mK*mK+d1->GetP()*d1->GetP());
28 energy[0] = TMath::Sqrt(mpi*mpi+d2->GetP()*d2->GetP());
34 Double_t momTot2 = (p1[0]+p2[0])*(p1[0]+p2[0])+
35 (p1[1]+p2[1])*(p1[1]+p2[1])+
36 (p1[2]+p2[2])*(p1[2]+p2[2]);
38 return TMath::Sqrt((energy[0]+energy[1])*(energy[0]+energy[1])-momTot2);
41 void AliHLTD0toKpi::cosThetaStar(AliExternalTrackParam* d1, AliExternalTrackParam* d2,Double_t &D0,Double_t &D0bar)
43 Double_t mD0 = TDatabasePDG::Instance()->GetParticle(421)->Mass();
44 Double_t mpi=TDatabasePDG::Instance()->GetParticle(211)->Mass();
45 Double_t mK=TDatabasePDG::Instance()->GetParticle(321)->Mass();
47 Double_t pStar = TMath::Sqrt(TMath::Power(mD0*mD0-mK*mK-mpi*mpi,2.)-4.*mK*mK*mpi*mpi)/(2.*mD0);
49 Double_t px = d1->Px()+d2->Px();
50 Double_t py = d1->Py()+d2->Py();
51 Double_t pz = d1->Pz()+d2->Pz();
52 Double_t p = TMath::Sqrt(px*px+py*py+pz*pz);
53 Double_t energy = TMath::Sqrt(p*p+mD0*mD0);
55 Double_t beta = p/energy;
56 Double_t gamma = energy/mD0;
59 TVector3 mom(d1->Px(),d1->Py(),d1->Pz());
60 TVector3 momD(px,py,pz);
61 qL = mom.Dot(momD)/momD.Mag();
63 D0 = (qL/gamma-beta*TMath::Sqrt(pStar*pStar+mK*mK))/pStar;
65 TVector3 mom2(d2->Px(),d2->Py(),d2->Pz());
66 TVector3 momD2(px,py,pz);
67 qL = mom2.Dot(momD2)/momD2.Mag();
69 D0bar = (qL/gamma-beta*TMath::Sqrt(pStar*pStar+mK*mK))/pStar;
72 Double_t AliHLTD0toKpi::pointingAngle(AliExternalTrackParam* n, AliExternalTrackParam* p, Double_t *pv, Double_t *sv)
75 TVector3 mom(n->Px()+p->Px(),n->Py()+p->Py(),n->Pz()+p->Pz());
76 TVector3 flight(sv[0]-pv[0],sv[1]-pv[1],sv[2]-pv[2]);
78 double pta = mom.Angle(flight);
80 return TMath::Cos(pta);
83 AliAODVertex* AliHLTD0toKpi::ReconstructSecondaryVertex(TObjArray *trkArray, Double_t b, const AliESDVertex *v, bool useKF)
86 AliESDVertex *vertexESD = 0;
87 AliAODVertex *vertexAOD = 0;
90 AliVertexerTracks *vertexer = new AliVertexerTracks(b);
91 AliESDVertex* vertex = new AliESDVertex(*((AliESDVertex*)v));
92 //AliESDVertex* vertex = const_cast<AliESDVertex*>(v);
93 vertexer->SetVtxStart(vertex);
94 vertexESD = (AliESDVertex*)vertexer->VertexForSelectedESDTracks(trkArray);
95 delete vertexer; vertexer=NULL;
98 if(!vertexESD) return vertexAOD;
100 if(vertexESD->GetNContributors()!=trkArray->GetEntriesFast()) {
101 //AliDebug(2,"vertexing failed");
102 delete vertexESD; vertexESD=NULL;
107 AliKFParticle::SetField(b);
109 AliKFVertex vertexKF;
111 Int_t nTrks = trkArray->GetEntriesFast();
112 for(Int_t i=0; i<nTrks; i++) {
113 AliESDtrack *esdTrack = (AliESDtrack*)trkArray->At(i);
114 AliKFParticle daughterKF(*esdTrack,211);
115 vertexKF.AddDaughter(daughterKF);
117 vertexESD = new AliESDVertex(vertexKF.Parameters(),
118 vertexKF.CovarianceMatrix(),
120 vertexKF.GetNContributors());
122 // convert to AliAODVertex
123 Double_t pos[3],cov[6],chi2perNDF;
124 vertexESD->GetXYZ(pos); // position
125 vertexESD->GetCovMatrix(cov); //covariance matrix
126 chi2perNDF = vertexESD->GetChi2toNDF();
127 //dispersion = vertexESD->GetDispersion();
128 delete vertexESD; vertexESD=NULL;
130 Int_t nprongs= trkArray->GetEntriesFast();
131 vertexAOD = new AliAODVertex(pos,cov,chi2perNDF,0x0,-1,AliAODVertex::kUndef,nprongs);
136 Double_t AliHLTD0toKpi::Pt(AliExternalTrackParam* d1, AliExternalTrackParam* d2)
138 Double_t p1[3],p2[3];
142 Double_t pt2 = (p1[0]+p2[0])*(p1[0]+p2[0]) + (p1[1]+p2[1])*(p1[1]+p2[1]);
144 return TMath::Sqrt(pt2);