2 // Class AliRsnPairParticle
4 // Implementation of a pair of tracks, for several purposes
5 // - computing the total 4-momentum & inv. mass for output histos filling
6 // - evaluating cut checks on the pair of particles
7 // - evaluating any kind of kinematic value over their sum
9 // authors: Martin Vala (martin.vala@cern.ch)
10 // Alberto Pulvirenti (alberto.pulvirenti@ct.infn.it)
13 #ifndef ALIRSNPAIRPARTICLE_H
14 #define ALIRSNPAIRPARTICLE_H
18 #include "AliRsnDaughter.h"
22 class AliRsnPairParticle : public TObject
27 AliRsnPairParticle(const AliRsnPairParticle &obj);
28 AliRsnPairParticle& operator=(const AliRsnPairParticle &obj);
29 virtual ~AliRsnPairParticle();
31 Double_t GetInvMass(Double_t m1, Double_t m2);
32 Double_t GetInvMassMC(Double_t m1, Double_t m2);
34 Double_t GetEtot(Double_t m1, Double_t m2) const;
35 Double_t GetEtot(Double_t mass) const {return TMath::Sqrt(mass*mass + GetP2());}
36 Double_t GetP2() const {return (fPTot[0]*fPTot[0] + fPTot[1]*fPTot[1] + fPTot[2]*fPTot[2]);}
37 Double_t GetPt2() const {return (fPTot[0]*fPTot[0] + fPTot[1]*fPTot[1]);}
38 Double_t GetP() const {return TMath::Sqrt(GetP2());}
39 Double_t GetPx() const {return fPTot[0];}
40 Double_t GetPy() const {return fPTot[1];}
41 Double_t GetPz() const {return fPTot[2];}
42 Double_t GetPt() const {return TMath::Sqrt(GetPt2());}
43 Double_t GetPhi() const {return TMath::Pi() + TMath::ATan2(-fPTot[1], -fPTot[0]);}
44 Double_t GetTheta() const {
45 if (fPTot[2]==0.0) {return TMath::PiOver2();}
46 else {return TMath::ACos(fPTot[2]/GetP());}
48 Double_t GetEta() const {Double_t a = TMath::Tan(0.5*GetTheta()); if (a > 0.) return -TMath::Log(a); return 999999.0;}
49 Double_t GetY(Double_t m1, Double_t m2) const {return 0.5*TMath::Log((GetEtot(m1,m2)+fPTot[2])/(GetEtot(m1,m2)-fPTot[2]));}
50 Double_t GetY(Double_t mass) const {return 0.5*TMath::Log((GetEtot(mass)+fPTot[2])/(GetEtot(mass)-fPTot[2]));}
52 Double_t GetEtotMC(Double_t m1, Double_t m2) const;
53 Double_t GetEtotMC(Double_t mass) const {return TMath::Sqrt(mass*mass + GetP2MC());}
54 Double_t GetP2MC() const {return (fPTotMC[0]*fPTotMC[0] + fPTotMC[1]*fPTotMC[1] + fPTotMC[2]*fPTotMC[2]);}
55 Double_t GetPt2MC() const {return (fPTotMC[0]*fPTotMC[0] + fPTotMC[1]*fPTotMC[1]);}
56 Double_t GetPMC() const {return TMath::Sqrt(GetP2MC());}
57 Double_t GetPxMC() const {return fPTotMC[0];}
58 Double_t GetPyMC() const {return fPTotMC[1];}
59 Double_t GetPzMC() const {return fPTotMC[2];}
60 Double_t GetPtMC() const {return TMath::Sqrt(GetPt2MC());}
61 Double_t GetPhiMC() const {return TMath::Pi() + TMath::ATan2(-fPTotMC[1], -fPTotMC[0]);}
62 Double_t GetThetaMC() const {
63 if (fPTotMC[2]==0.0) {return TMath::PiOver2();}
64 else {return TMath::ACos(fPTotMC[2]/GetPMC());}
66 Double_t GetEtaMC() const {return -TMath::Log(TMath::Tan(0.5*GetThetaMC()));}
67 Double_t GetYMC(Double_t m1, Double_t m2) const {return 0.5*TMath::Log((GetEtotMC(m1,m2)+fPTotMC[2])/(GetEtotMC(m1,m2)-fPTotMC[2]));}
68 Double_t GetYMC(Double_t mass) const {return 0.5*TMath::Log((GetEtotMC(mass)+fPTot[2])/(GetEtotMC(mass)-fPTot[2]));}
70 Double_t GetAngle() const;
72 AliRsnDaughter* GetDaughter(const Int_t &index) const {return fDaughter[index];}
74 Bool_t IsLabelEqual() {return abs(fDaughter[0]->GetLabel()) == abs(fDaughter[1]->GetLabel());}
75 Bool_t IsIndexEqual() {return (fDaughter[0]->GetID() == fDaughter[1]->GetID());}
76 Bool_t IsTruePair(Int_t refPDG = 0);
79 void SetPair(AliRsnDaughter * const daughter1, AliRsnDaughter * const daughter2);
81 void RotateTrack(Int_t i, Double_t angle, Bool_t isDegrees = kTRUE);
82 void PrintInfo(const Option_t *option = "ALL");
83 Bool_t MatchesDef(AliRsnPairDef *def);
87 Double_t fPTot[3]; // total momentum computed with rec. values
88 Double_t fPTotMC[3]; // total momentum computed with MC values
89 Double_t fPTrack[2][3]; // rec. momentum of single tracks
90 Double_t fPTrackMC[2][3]; // MC momentum of single tracks
92 Int_t fMotherLabel[2]; // GEANT label of tracks
93 Int_t fMotherPDG[2]; // PDG code of mother of tracks
95 AliRsnDaughter *fDaughter[2]; // elements of the pair
97 ClassDef(AliRsnPairParticle,1)