1 /**************************************************************************
2 * Copyright(c) 1998-2008, 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 **************************************************************************/
16 /////////////////////////////////////////////////////////////
18 // Class for AOD reconstructed heavy-flavour cascades
20 // Author: X-M. Zhang, zhangxm@iop.ccnu.edu.cn
21 /////////////////////////////////////////////////////////////
24 #include <TDatabasePDG.h>
25 #include "AliAODRecoDecay.h"
26 #include "AliAODVertex.h"
27 #include "AliAODRecoDecayHF2Prong.h"
28 #include "AliAODRecoCascadeHF.h"
30 ClassImp(AliAODRecoCascadeHF)
31 //-----------------------------------------------------------------------------
33 AliAODRecoCascadeHF::AliAODRecoCascadeHF() :
34 AliAODRecoDecayHF2Prong(),
38 // Default Constructor
41 //-----------------------------------------------------------------------------
42 AliAODRecoCascadeHF::AliAODRecoCascadeHF(AliAODVertex *vtx2, Short_t charge,
43 Double_t *px, Double_t *py, Double_t *pz,
44 Double_t *d0, Double_t *d0err, Double_t dca) :
45 AliAODRecoDecayHF2Prong(vtx2, px, py, pz, d0, d0err, dca),
49 // Constructor with AliAODVertex for decay vertex
53 //-----------------------------------------------------------------------------
54 AliAODRecoCascadeHF::AliAODRecoCascadeHF(AliAODVertex *vtx2, Short_t charge,
55 Double_t *d0, Double_t *d0err, Double_t dca) :
56 AliAODRecoDecayHF2Prong(vtx2, d0, d0err, dca),
60 // Constructor with decay vertex and without prongs momenta
64 //-----------------------------------------------------------------------------
65 AliAODRecoCascadeHF::AliAODRecoCascadeHF(const AliAODRecoCascadeHF &source) :
66 AliAODRecoDecayHF2Prong(source),
73 //-----------------------------------------------------------------------------
74 AliAODRecoCascadeHF &AliAODRecoCascadeHF::operator=(const AliAODRecoCascadeHF &source)
77 // assignment operator
79 if(&source == this) return *this;
81 AliAODRecoDecayHF2Prong::operator=(source);
83 f2Prong = source.f2Prong;
87 //-----------------------------------------------------------------------------
88 AliAODRecoCascadeHF::~AliAODRecoCascadeHF()
94 //-----------------------------------------------------------------------------
95 Double_t AliAODRecoCascadeHF::InvMassDstarKpipi() const
98 // 3 prong invariant mass of the D0 daughters and the soft pion
101 Double_t px[3],py[3],pz[3];
102 UInt_t pdg[3]={321,211,211};
103 pdg[0] = (Charge()>0 ? 211 : 321); // positive daughter of D0
104 px[0] = Get2Prong()->PxProng(0);
105 py[0] = Get2Prong()->PyProng(0);
106 pz[0] = Get2Prong()->PzProng(0);
107 pdg[1] = (Charge()>0 ? 321 : 211); // negative daughter of D0
108 px[1] = Get2Prong()->PxProng(1);
109 py[1] = Get2Prong()->PyProng(1);
110 pz[1] = Get2Prong()->PzProng(1);
111 pdg[2] = 211; // soft pion
115 Short_t dummycharge=0;
116 Double_t dummyd0[3]={0,0,0};
117 AliAODRecoDecay *rd = new AliAODRecoDecay(0x0,3,dummycharge,px,py,pz,dummyd0);
119 Double_t minv = rd->InvMass(3,pdg);
125 //-----------------------------------------------------------------------------
126 Bool_t AliAODRecoCascadeHF::SelectDstar(const Double_t *cutsDstar,
127 const Double_t *cutsD0,
131 // cutsDstar[0] = inv. mass half width of D* [GeV]
132 // cutsDstar[1] = half width of (M_Kpipi-M_D0) [GeV]
133 // cutsDstar[2] = PtMin of pi_s [GeV/c]
134 // cutsDstar[3] = PtMax of pi_s [GeV/c]
135 // cutsDstar[4] = theta, angle between the pi_s and decay plane of the D0 [rad]
137 // cutsD0[0] = inv. mass half width [GeV]
138 // cutsD0[1] = dca [cm]
139 // cutsD0[2] = cosThetaStar
140 // cutsD0[3] = pTK [GeV/c]
141 // cutsD0[4] = pTPi [GeV/c]
142 // cutsD0[5] = d0K [cm] upper limit!
143 // cutsD0[6] = d0Pi [cm] upper limit!
144 // cutsD0[7] = d0d0 [cm^2]
145 // cutsD0[8] = cosThetaPoint
148 // check that the D0 passes the cuts
149 // (if we have a D*+, it has to pass as D0,
150 // if we have a D*-, it has to pass as D0bar)
153 Int_t okD0=0,okD0bar=0;
154 Get2Prong()->SelectD0(cutsD0,okD0,okD0bar);
155 if((Charge()==+1 && !okD0) || (Charge()==-1 && !okD0bar)) return kFALSE;
158 if( (PtProng(0)<cutsDstar[2]) || (PtProng(0)>cutsDstar[3]) ) return kFALSE;
160 Double_t mDstar = TDatabasePDG::Instance()->GetParticle(413)->Mass();
161 Double_t invmDstar = InvMassDstarKpipi();
162 if(TMath::Abs(mDstar-invmDstar)>cutsDstar[0]) return kFALSE;
164 Double_t mD0 = TDatabasePDG::Instance()->GetParticle(421)->Mass();
165 if(TMath::Abs((mDstar-mD0)-DeltaInvMass())>cutsDstar[1]) return kFALSE;
167 TVector3 p3Trk0(Get2Prong()->PxProng(0),Get2Prong()->PyProng(0),Get2Prong()->PzProng(0)); // from D0
168 TVector3 p3Trk1(Get2Prong()->PxProng(1),Get2Prong()->PyProng(1),Get2Prong()->PzProng(1)); // from D0
169 TVector3 p3Trk2(PxProng(0),PyProng(0),PzProng(0)); // pi_s
171 TVector3 perp = p3Trk0.Cross(p3Trk1);
172 Double_t theta = p3Trk2.Angle(perp);
173 if(theta>(TMath::Pi()-theta)) theta = TMath::Pi() - theta;
174 theta = TMath::Pi()/2. - theta;
176 if(theta>cutsDstar[4]) return kFALSE;
178 Double_t alpha = p3Trk0.Angle(p3Trk2);
179 Double_t belta = p3Trk1.Angle(p3Trk2);
181 Double_t cosphi01 = TMath::Cos(alpha) / TMath::Cos(theta);
182 Double_t cosphi02 = TMath::Cos(belta) / TMath::Cos(theta);
184 Double_t phi01 = TMath::ACos(cosphi01);
185 Double_t phi02 = TMath::ACos(cosphi02);
186 Double_t phi00 = p3Trk0.Angle(p3Trk1);
188 if((phi01>phi00) || (phi02>phi00)) return kFALSE;
192 //-----------------------------------------------------------------------------