4 /* Copyright(c) 2004-2005, ALICE Experiment at CERN, All rights reserved. *
5 * See cxx source for full Copyright notice */
7 //-------------------------------------------------------------------------
8 // Implementation of the Analysis Oriented Data (AOD) V0 vertex class
9 // Origin: B.Hippolyte, IReS, hippolyt@in2p3.fr
10 // G.Van Buren, BNL, gene@bnl.gov (original STAR MuDsts)
11 // Purpose: Having observables for physics available for V0s
12 //-------------------------------------------------------------------------
15 #include <TDatabasePDG.h>
17 #define MASS(PID) TDatabasePDG::Instance()->GetParticle((PID))->Mass()
18 #define MASS2(PID) MASS((PID))*MASS((PID))
26 class AliAODv0 : public TObject {
30 AliAODv0(AliESDv0 *rV0Vertex, AliESD *rEvent);
31 AliAODv0(const AliAODv0& rAliAODv0);
34 AliAODv0& operator=(const AliAODv0& rAliAODv0);
36 void Fill(AliESDv0 *rV0Vertex, AliESD *rEvent);
39 Double_t DecayVertexV0X() const;
40 Double_t DecayVertexV0Y() const;
41 Double_t DecayVertexV0Z() const;
43 Double_t DecayLengthV0(double*) const;
45 Double_t DcaV0Daughters() const;
46 Double_t DcaV0ToPrimVertex() const;
47 Double_t DcaPosToPrimVertex() const;
48 Double_t DcaNegToPrimVertex() const;
49 Double_t CosPointAngle(Double_t&, Double_t&, Double_t&) const;
50 Double_t RadiusV0() const;
51 Double_t OpenAngleV0() const;
53 Double_t MomPosX() const;
54 Double_t MomPosY() const;
55 Double_t MomPosZ() const;
56 Double_t MomNegX() const;
57 Double_t MomNegY() const;
58 Double_t MomNegZ() const;
63 Double_t Chi2V0() const;
65 Double_t MomV0X() const;
66 Double_t MomV0Y() const;
67 Double_t MomV0Z() const;
69 Double_t Ptot2Pos() const;
70 Double_t Ptot2Neg() const;
71 Double_t Ptot2V0() const;
72 Double_t Pt2V0() const;
73 Double_t MomPosAlongV0() const;
74 Double_t MomNegAlongV0() const;
75 Double_t AlphaV0() const;
76 Double_t PtArmV0() const;
77 Double_t EPosProton() const;
78 Double_t ENegProton() const;
79 Double_t EPosPion() const;
80 Double_t ENegPion() const;
81 Double_t ELambda() const;
82 Double_t EK0Short() const;
83 Double_t MassLambda() const;
84 Double_t MassAntiLambda() const;
85 Double_t MassK0Short() const;
86 Double_t RapK0Short() const;
87 Double_t RapLambda() const;
88 Double_t PseudoRapV0() const;
89 Double_t PseudoRapPos() const;
90 Double_t PseudoRapNeg() const;
94 Double_t fDecayVertexV0X; // decay vertex of V0 along X
95 Double_t fDecayVertexV0Y; // decay vertex of V0 along Y
96 Double_t fDecayVertexV0Z; // decay vertex of V0 along Z
97 Double_t fDcaV0Daughters; // dca between V0 daughters
98 Double_t fDcaV0ToPrimVertex; // dca of V0 to primary vertex
99 Double_t fDcaPosToPrimVertex; // dca of pos daughter to primary vertex
100 Double_t fDcaNegToPrimVertex; // dca of pos daughter to primary vertex
101 Double_t fMomPosX; // momemtum of pos daughter along X
102 Double_t fMomPosY; // momemtum of pos daughter along Y
103 Double_t fMomPosZ; // momemtum of pos daughter along Z
104 Double_t fMomNegX; // momemtum of neg daughter along X
105 Double_t fMomNegY; // momemtum of neg daughter along Y
106 Double_t fMomNegZ; // momemtum of neg daughter along Z
108 UInt_t fKeyPos; // track key/index to pos daughter
109 UInt_t fKeyNeg; // track key/index to neg daughter
111 Double_t fChi2; // main quality variable of V0
116 inline Double_t AliAODv0::DecayVertexV0X() const {return fDecayVertexV0X;}
117 inline Double_t AliAODv0::DecayVertexV0Y() const {return fDecayVertexV0Y;}
118 inline Double_t AliAODv0::DecayVertexV0Z() const {return fDecayVertexV0Z;}
120 inline Double_t AliAODv0::DecayLengthV0(double *tParentVertexPosition) const {
121 return ::sqrt(::pow(DecayVertexV0X() - tParentVertexPosition[0],2) +
122 ::pow(DecayVertexV0Y() - tParentVertexPosition[1],2) +
123 ::pow(DecayVertexV0Z() - tParentVertexPosition[2],2));
126 inline Double_t AliAODv0::DcaV0Daughters() const {return fDcaV0Daughters;}
127 inline Double_t AliAODv0::DcaV0ToPrimVertex() const {return fDcaV0ToPrimVertex;}
128 inline Double_t AliAODv0::DcaPosToPrimVertex() const {return fDcaPosToPrimVertex;}
129 inline Double_t AliAODv0::DcaNegToPrimVertex() const {return fDcaNegToPrimVertex;}
131 inline Double_t AliAODv0::MomPosX() const {return fMomPosX;}
132 inline Double_t AliAODv0::MomPosY() const {return fMomPosY;}
133 inline Double_t AliAODv0::MomPosZ() const {return fMomPosZ;}
134 inline Double_t AliAODv0::MomNegX() const {return fMomNegX;}
135 inline Double_t AliAODv0::MomNegY() const {return fMomNegY;}
136 inline Double_t AliAODv0::MomNegZ() const {return fMomNegZ;}
138 inline Int_t AliAODv0::KeyPos() const {return fKeyPos;}
139 inline Int_t AliAODv0::KeyNeg() const {return fKeyNeg;}
141 inline Double_t AliAODv0::Chi2V0() const {return fChi2;}
143 inline Double_t AliAODv0::CosPointAngle(Double_t& refPointX, Double_t& refPointY, Double_t& refPointZ) const {
145 Double_t deltaPos[3]; //vector between the reference point and the V0 vertex
146 deltaPos[0] = fDecayVertexV0X - refPointX;
147 deltaPos[1] = fDecayVertexV0Y - refPointY;
148 deltaPos[2] = fDecayVertexV0Z - refPointZ;
150 Double_t deltaPos2 = deltaPos[0]*deltaPos[0] + deltaPos[1]*deltaPos[1] + deltaPos[2]*deltaPos[2];
152 Double_t cosinePointingAngle = (deltaPos[0]*MomV0X() +
153 deltaPos[1]*MomV0Y() +
154 deltaPos[2]*MomV0Z() ) /
155 TMath::Sqrt(Ptot2V0() * deltaPos2);
156 return cosinePointingAngle;
159 inline Double_t AliAODv0::MomV0X() const {return MomPosX()+MomNegX();}
160 inline Double_t AliAODv0::MomV0Y() const {return MomPosY()+MomNegY();}
161 inline Double_t AliAODv0::MomV0Z() const {return MomPosZ()+MomNegZ();}
163 inline Double_t AliAODv0::Ptot2Pos() const {
164 return (::pow(MomPosX(),2) + ::pow(MomPosY(),2) + ::pow(MomPosZ(),2) );
166 inline Double_t AliAODv0::Ptot2Neg() const {
167 return (::pow(MomNegX(),2) + ::pow(MomNegY(),2) + ::pow(MomNegZ(),2) );
169 inline Double_t AliAODv0::Pt2V0() const {
170 return (::pow(MomV0X(),2) + ::pow(MomV0Y(),2) );
173 inline Double_t AliAODv0::Ptot2V0() const {return ( Pt2V0() + ::pow(MomV0Z(),2) );}
175 inline Double_t AliAODv0::MomPosAlongV0() const {
176 Double_t lPtot2V0 = Ptot2V0();
178 return (MomPosX()*MomV0X() +
180 MomPosZ()*MomV0Z()) / ::sqrt(lPtot2V0);
184 inline Double_t AliAODv0::MomNegAlongV0() const {
185 Double_t lPtot2V0 = Ptot2V0();
187 return (MomNegX()*MomV0X() +
189 MomNegZ()*MomV0Z()) / ::sqrt(lPtot2V0);
193 inline Double_t AliAODv0::AlphaV0() const {
194 return 1.-(2./(1.+(MomPosAlongV0()/MomNegAlongV0())));
196 inline Double_t AliAODv0::PtArmV0() const {
197 return ::sqrt(Ptot2Pos()-MomPosAlongV0()*MomPosAlongV0());
200 inline Double_t AliAODv0::EPosProton() const {
201 return ::sqrt(Ptot2Pos()+MASS2("proton"));
204 inline Double_t AliAODv0::ENegProton() const {
205 return ::sqrt(Ptot2Neg()+MASS2("antiproton"));
208 inline Double_t AliAODv0::EPosPion() const {
209 return ::sqrt(Ptot2Pos()+MASS2("pi+"));
212 inline Double_t AliAODv0::ENegPion() const {
213 return ::sqrt(Ptot2Neg()+MASS2("pi-"));
216 inline Double_t AliAODv0::ELambda() const {
217 return ::sqrt(Ptot2V0()+MASS2("Lambda0"));
220 inline Double_t AliAODv0::EK0Short() const {
221 return ::sqrt(Ptot2V0()+MASS2("K_S0"));
224 inline Double_t AliAODv0::MassLambda() const {
225 return ::sqrt(::pow(EPosProton()+ENegPion(),2)-Ptot2V0());
228 inline Double_t AliAODv0::MassAntiLambda() const {
229 return ::sqrt(::pow(ENegProton()+EPosPion(),2)-Ptot2V0());
232 inline Double_t AliAODv0::MassK0Short() const {
233 return ::sqrt(::pow(EPosPion()+ENegPion(),2)-Ptot2V0());
236 inline Double_t AliAODv0::RapK0Short() const {
237 Double_t ek0 = EK0Short();
238 Double_t mMomV0Z = MomV0Z();
239 return 0.5*::log((ek0+mMomV0Z)/(ek0-mMomV0Z));
242 inline Double_t AliAODv0::RapLambda() const {
243 Double_t eLambda = ELambda();
244 Double_t mMomV0Z = MomV0Z();
245 return 0.5*::log((eLambda+mMomV0Z)/(eLambda-mMomV0Z));
248 inline Double_t AliAODv0::RadiusV0() const {
249 return ::sqrt( fDecayVertexV0X*fDecayVertexV0X
250 + fDecayVertexV0Y*fDecayVertexV0Y );
253 inline Double_t AliAODv0::PseudoRapV0() const {
254 Double_t lTheta = ::acos( MomV0Z()/::sqrt(Ptot2V0()) );
255 return ( -::log(TMath::Tan(lTheta/2.)) );
258 inline Double_t AliAODv0::PseudoRapPos() const {
259 Double_t lTheta = ::acos( MomPosZ()/::sqrt(Ptot2Pos()) );
260 return ( -::log(TMath::Tan(lTheta/2.)) );
263 inline Double_t AliAODv0::PseudoRapNeg() const {
264 Double_t lTheta = ::acos( MomNegZ()/::sqrt(Ptot2Neg()) );
265 return ( -::log(TMath::Tan(lTheta/2.)) );
268 inline Double_t AliAODv0::OpenAngleV0() const {
269 Double_t lPtot1xPtot2 = fMomPosX*fMomNegX+fMomPosY*fMomNegY+fMomPosZ*fMomNegZ;
270 Double_t lPtot1Ptot2_2 = Ptot2Pos()*Ptot2Neg();
271 return ::acos(lPtot1xPtot2/::sqrt(lPtot1Ptot2_2) );