1 /**************************************************************************
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2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
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4 * Author: The ALICE Off-line Project. *
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5 * Contributors are mentioned in the code where appropriate. *
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7 * Permission to use, copy, modify and distribute this software and its *
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8 * documentation strictly for non-commercial purposes is hereby granted *
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9 * without fee, provided that the above copyright notice appears in all *
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10 * copies and that both the copyright notice and this permission notice *
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11 * appear in the supporting documentation. The authors make no claims *
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12 * about the suitability of this software for any purpose. It is *
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13 * provided "as is" without express or implied warranty. *
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14 **************************************************************************/
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17 * author: M.Kalisky@gsi.de
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20 * Description: This class allows with purely kinematical cuts
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21 * to select clean samples of electrons, pions and protons from the
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22 * V0 online finder ESD V0 candidates for PID and dectector resonse
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26 #include <TVector3.h>
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27 #include <TDatabasePDG.h>
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29 #include "AliESDv0.h"
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30 #include "AliESDtrack.h"
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31 #include "AliESDEvent.h"
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32 #include "AliVEvent.h"
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34 #include "AliKFParticle.h"
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35 #include "AliVTrack.h"
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36 #include "AliKFVertex.h"
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38 #include "AliESDv0KineCuts.h"
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40 ClassImp(AliESDv0KineCuts)
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42 //____________________________________________________________________
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43 AliESDv0KineCuts::AliESDv0KineCuts() :
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45 , fPrimaryVertex(0x0)
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50 , fTPCchi2perCls(4.0)
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54 , fGcutInvMass(0.05)
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57 , fUseExternalVertex(kFALSE)
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58 , fDeleteVertex(kFALSE)
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61 // Default constructor
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64 // default single track cuts
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65 fTPCNcls = 1; // minimal number of the TPC clusters
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66 fTPCrefit = kTRUE; // TPC refit
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67 fTPCchi2perCls = 4.0; // chi2 per TPC cluster
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68 fTPCclsRatio = 0.6; // minimal foun/findable TPC cluster ratio
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69 fNoKinks = kTRUE; // kinks - no [kTRUE] or do not care [kFalse]
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72 // default gamma cuts values
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73 fGcutChi2NDF = 10; // Chi2NF cut value for the AliKFparticle gamma
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74 fGcutCosPoint[0] = 0; // cos of the pointing angle [min, max]
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75 fGcutCosPoint[1] = 0.02; // cos of the pointing angle [min, max]
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76 fGcutDCA[0] = 0.; // DCA between the daughter tracks [min, max]
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77 fGcutDCA[1] = 0.25; // DCA between the daughter tracks [min, max]
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78 fGcutVertexR[0] = 3.; // radius of the conversion point [min, max]
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79 fGcutVertexR[1] = 90.; // radius of the conversion point [min, max]
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80 fGcutPsiPair[0] = 0.; // value of the psi pair cut [min, max]
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81 fGcutPsiPair[1] = 0.05; // value of the psi pair cut [min, max]
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82 fGcutInvMass = 0.05; // upper value on the gamma invariant mass
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84 fK0cutChi2NDF = 10; // Chi2NF cut value for the AliKFparticle K0
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85 fK0cutCosPoint[0] = 0.; // cos of the pointing angle [min, max]
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86 fK0cutCosPoint[1] = 0.02; // cos of the pointing angle [min, max]
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87 fK0cutDCA[0] = 0.; // DCA between the daughter tracks [min, max]
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88 fK0cutDCA[1] = 0.2; // DCA between the daughter tracks [min, max]
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89 fK0cutVertexR[0] = 2.0; // radius of the decay point [min, max]
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90 fK0cutVertexR[1] = 30.0; // radius of the decay point [min, max]
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91 fK0cutInvMass[0] = 0.486; // invariant mass window
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92 fK0cutInvMass[1] = 0.508; // invariant mass window
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93 // Lambda & anti-Lambda cut values
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94 fLcutChi2NDF = 10; // Chi2NF cut value for the AliKFparticle K0
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95 fLcutCosPoint[0] = 0.; // cos of the pointing angle [min, max]
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96 fLcutCosPoint[1] = 0.02; // cos of the pointing angle [min, max]
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97 fLcutDCA[0] = 0.; // DCA between the daughter tracks [min, max]
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98 fLcutDCA[1] = 0.2; // DCA between the daughter tracks [min, max]
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99 fLcutVertexR[0] = 2.0; // radius of the decay point [min, max]
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100 fLcutVertexR[1] = 40.0; // radius of the decay point [min, max]
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101 fLcutInvMass[0] = 1.11; // invariant mass window
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102 fLcutInvMass[1] = 1.12; // invariant mass window
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105 //____________________________________________________________________
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106 AliESDv0KineCuts::~AliESDv0KineCuts(){
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113 //____________________________________________________________________
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114 AliESDv0KineCuts::AliESDv0KineCuts(const AliESDv0KineCuts &ref):
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117 , fPrimaryVertex(0x0)
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122 , fTPCchi2perCls(4.0)
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123 , fTPCclsRatio(0.6)
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126 , fGcutInvMass(0.05)
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127 , fK0cutChi2NDF(10)
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129 , fUseExternalVertex(kFALSE)
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130 , fDeleteVertex(kFALSE)
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138 //____________________________________________________________________
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139 AliESDv0KineCuts &AliESDv0KineCuts::operator=(const AliESDv0KineCuts &ref){
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141 // assignment operator
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147 //____________________________________________________________________
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148 void AliESDv0KineCuts::Copy(TObject &ref) const {
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150 // Performs the copying of the object
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153 TObject::Copy(ref);
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155 AliESDv0KineCuts &target = dynamic_cast<AliESDv0KineCuts &>(ref);
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157 // default single track cuts
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158 target.fTPCNcls = fTPCNcls;
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159 target.fTPCrefit = fTPCrefit;
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160 target.fTPCchi2perCls = fTPCchi2perCls;
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161 target.fTPCclsRatio = fTPCclsRatio;
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162 target.fNoKinks = fNoKinks;
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163 target.fUseExternalVertex = fUseExternalVertex; //added december 2nd 2011
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164 target.fDeleteVertex = fDeleteVertex; //added december 2nd 2011
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166 // default gamma cuts values
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167 target.fGcutChi2NDF = fGcutChi2NDF;
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168 memcpy(target.fGcutCosPoint, fGcutCosPoint, sizeof(Float_t) * 2);
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169 memcpy(target.fGcutDCA, fGcutDCA, sizeof(Float_t) * 2);
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170 memcpy(target.fGcutVertexR, fGcutVertexR, sizeof(Float_t) * 2);
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171 memcpy(target.fGcutPsiPair, fGcutPsiPair, sizeof(Float_t) * 2);
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172 target.fGcutInvMass = fGcutInvMass;
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174 target.fK0cutChi2NDF = fK0cutChi2NDF;
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175 memcpy(target.fK0cutCosPoint, fK0cutCosPoint, sizeof(Float_t) * 2);
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176 memcpy(target.fK0cutDCA, fK0cutDCA, sizeof(Float_t) * 2);
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177 memcpy(target.fK0cutVertexR, fK0cutVertexR, sizeof(Float_t) * 2);
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178 memcpy(target.fK0cutInvMass, fK0cutInvMass, sizeof(Float_t) * 2);
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179 // Lambda & anti-Lambda cut values
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180 target.fLcutChi2NDF = fLcutChi2NDF;
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181 memcpy(target.fLcutCosPoint, fLcutCosPoint, sizeof(Float_t) * 2);
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182 memcpy(target.fLcutDCA, fLcutDCA, sizeof(Float_t) * 2);
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183 memcpy(target.fLcutVertexR, fLcutVertexR, sizeof(Float_t) * 2);
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184 memcpy(target.fLcutInvMass, fLcutInvMass, sizeof(Float_t) * 2);
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187 //____________________________________________________________________
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188 Bool_t AliESDv0KineCuts::ProcessV0(AliESDv0* const v0, Int_t &pdgV0, Int_t &pdgP, Int_t &pdgN) const
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191 // main user function
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194 if(!v0) return kFALSE;
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196 AliErrorClass("No valid Event pointer available, provide it first");
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200 if(!V0CutsCommon(v0)) return kFALSE;
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202 const Int_t id = PreselectV0(v0);
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204 if(!SingleTrackCuts(v0)) return kFALSE;
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210 return CaseGamma(v0, pdgV0, pdgP, pdgN);
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212 return CaseK0(v0, pdgV0, pdgP, pdgN);
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214 return CaseLambda(v0, pdgV0, pdgP, pdgN, 0);
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216 return CaseLambda(v0, pdgV0, pdgP, pdgN, 1);
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223 //____________________________________________________________________
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224 Bool_t AliESDv0KineCuts::ProcessV0(AliESDv0* const v0, Int_t &pdgP, Int_t &pdgN) const
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227 // main user function, simplified if the V0 identity is not necessary
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230 if(!v0) return kFALSE;
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232 AliErrorClass("No valid Event pointer available, provide it first");
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237 return ProcessV0(v0, idV0, pdgP, pdgN);
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240 //____________________________________________________________________
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241 Int_t AliESDv0KineCuts::PreselectV0(AliESDv0* const v0) const
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244 // Make a preselection (exclusive) of the V0 cadidates based on
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246 // the armenteros cut values are currently fixed and user is not able to set them via
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247 // set funcions. The reason is that these cuts are optimized and furneter changes should
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248 // not be necessary. To prove otherwise please study in detail before changing the values
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251 Float_t ap[2] = {-1., -1.};
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252 Armenteros(v0, ap);
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254 const Float_t alpha = ap[0];
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255 const Float_t qt = ap[1];
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258 // - the reagions for different candidates must not overlap
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261 const Double_t cutAlphaG = 0.35;
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262 const Double_t cutQTG = 0.05;
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263 const Double_t cutAlphaG2[2] = {0.6, 0.8};
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264 const Double_t cutQTG2 = 0.04;
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267 const Float_t cutQTK0[2] = {0.1075, 0.215};
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268 const Float_t cutAPK0[2] = {0.199, 0.8}; // parameters for curved QT cut
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270 // Lambda & A-Lambda cuts
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271 const Float_t cutQTL = 0.03;
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272 const Float_t cutAlphaL[2] = {0.35, 0.7};
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273 const Float_t cutAlphaAL[2] = {-0.7, -0.35};
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274 const Float_t cutAPL[3] = {0.107, -0.69, 0.5}; // parameters fir curved QT cut
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277 if(kPurity == fMode){
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278 // Check for Gamma candidates
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280 if( (TMath::Abs(alpha) < cutAlphaG) ) return kGamma;
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282 // additional region - should help high pT gammas
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284 if( (TMath::Abs(alpha) > cutAlphaG2[0]) && (TMath::Abs(alpha) < cutAlphaG2[1]) ) return kGamma;
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287 if(kEffGamma == fMode){
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288 if(qt < cutQTG) return kGamma;
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292 // Check for K0 candidates
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293 Float_t q = cutAPK0[0] * TMath::Sqrt(TMath::Abs(1 - alpha*alpha/(cutAPK0[1]*cutAPK0[1])));
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294 if( (qt > cutQTK0[0]) && (qt < cutQTK0[1]) && (qt > q) ){
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298 // Check for Lambda candidates
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299 q = cutAPL[0] * TMath::Sqrt(TMath::Abs(1 - ( (alpha + cutAPL[1]) * (alpha + cutAPL[1]) ) / (cutAPL[2]*cutAPL[2]) ));
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300 if( (alpha > cutAlphaL[0]) && (alpha < cutAlphaL[1]) && (qt > cutQTL) && (qt < q) ){
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304 // Check for A-Lambda candidates
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305 q = cutAPL[0] * TMath::Sqrt(TMath::Abs(1 - ( (alpha - cutAPL[1]) * (alpha - cutAPL[1]) ) / (cutAPL[2]*cutAPL[2]) ));
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306 if( (alpha > cutAlphaAL[0]) && (alpha < cutAlphaAL[1]) && (qt > cutQTL) && (qt < q) ){
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312 //____________________________________________________________________
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313 Bool_t AliESDv0KineCuts::SingleTrackCuts(AliESDv0 * const v0) const
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316 // apply single track cuts
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317 // correct sign not relevat here
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320 if(!v0) return kFALSE;
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322 Int_t pIndex = 0, nIndex = 0;
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323 pIndex = v0->GetPindex();
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324 nIndex = v0->GetNindex();
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326 d[0] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(pIndex));
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327 d[1] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(nIndex));
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329 for(Int_t i=0; i<2; ++i){
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330 if(!d[i]) return kFALSE;
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333 ULong_t status = d[i]->GetStatus();
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335 // No. of TPC clusters leave to the users
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336 if(d[i]->GetTPCNcls() < 1) return kFALSE;
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339 if(!(status & AliESDtrack::kTPCrefit)) return kFALSE;
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341 // Chi2 per TPC cluster
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342 Int_t nTPCclusters = d[i]->GetTPCNcls();
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343 Float_t chi2perTPCcluster = d[i]->GetTPCchi2()/Float_t(nTPCclusters);
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344 if(chi2perTPCcluster > 4) return kFALSE;
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346 // TPC cluster ratio
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347 Float_t cRatioTPC = d[i]->GetTPCNclsF() > 0. ? static_cast<Float_t>(d[i]->GetTPCNcls())/static_cast<Float_t> (d[i]->GetTPCNclsF()) : 1.;
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348 if(cRatioTPC < 0.6) return kFALSE;
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351 if(d[i]->GetKinkIndex(0) != 0) return kFALSE;
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357 //____________________________________________________________________
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358 Bool_t AliESDv0KineCuts::CaseGamma(AliESDv0* const v0, Int_t &pdgV0, Int_t &pdgP, Int_t &pdgN) const
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361 // process the gamma conversion candidate
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364 if(!v0) return kFALSE;
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366 AliVTrack* daughter[2];
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367 Int_t pIndex = 0, nIndex = 0;
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369 Bool_t sign = CheckSigns(v0);
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371 pIndex = v0->GetPindex();
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372 nIndex = v0->GetNindex();
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375 pIndex = v0->GetNindex();
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376 nIndex = v0->GetPindex();
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378 daughter[0] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(pIndex));
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379 daughter[1] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(nIndex));
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380 if(!daughter[0] || !daughter[1]) return kFALSE;
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382 AliKFParticle *kfMother = CreateMotherParticle(daughter[0], daughter[1], TMath::Abs(kElectron), TMath::Abs(kElectron));
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383 if(!kfMother) return kFALSE;
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386 d[0] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(pIndex));
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387 d[1] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(nIndex));
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389 Float_t iMass = v0->GetEffMass(0, 0);
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391 // cos pointing angle
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392 Double_t cosPoint = v0->GetV0CosineOfPointingAngle();
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393 cosPoint = TMath::ACos(cosPoint);
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395 // DCA between daughters
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396 Double_t dca = v0->GetDcaV0Daughters();
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398 // Production vertex
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401 Double_t r = TMath::Sqrt(x*x + y*y);
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405 if ( GetConvPosXY(d[0], d[1], xy) ){
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406 r2 = TMath::Sqrt(xy[0]*xy[0] + xy[1]*xy[1]);
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410 Double_t psiPair = PsiPair(v0);
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413 Double_t chi2ndf = kfMother->GetChi2()/kfMother->GetNDF();
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415 if(kfMother) delete kfMother;
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419 if(iMass > fGcutInvMass) return kFALSE;
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421 if(chi2ndf > fGcutChi2NDF) return kFALSE;
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423 if(cosPoint < fGcutCosPoint[0] || cosPoint > fGcutCosPoint[1]) return kFALSE;
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425 if(dca < fGcutDCA[0] || dca > fGcutDCA[1]) return kFALSE;
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427 if(r < fGcutVertexR[0] || r > fGcutVertexR[1]) return kFALSE;
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429 if(psiPair < fGcutPsiPair[0] || psiPair > fGcutPsiPair[1]) return kFALSE;
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445 //____________________________________________________________________
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446 Bool_t AliESDv0KineCuts::CaseK0(AliESDv0* const v0, Int_t &pdgV0, Int_t &pdgP, Int_t &pdgN) const {
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448 // process the K0 candidate
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451 if(!v0) return kFALSE;
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453 AliVTrack* daughter[2];
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454 Int_t pIndex = 0, nIndex = 0;
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455 Bool_t sign = CheckSigns(v0);
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457 pIndex = v0->GetPindex();
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458 nIndex = v0->GetNindex();
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461 pIndex = v0->GetNindex();
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462 nIndex = v0->GetPindex();
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465 daughter[0] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(pIndex));
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466 daughter[1] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(nIndex));
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467 if(!daughter[0] || !daughter[1]) return kFALSE;
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469 AliKFParticle *kfMother = CreateMotherParticle(daughter[0], daughter[1], TMath::Abs(kPiPlus), TMath::Abs(kPiPlus));
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470 if(!kfMother) return kFALSE;
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473 d[0] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(pIndex));
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474 d[1] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(nIndex));
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476 Float_t iMass = v0->GetEffMass(2, 2);
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478 // cos pointing angle
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479 Double_t cosPoint = v0->GetV0CosineOfPointingAngle();
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480 cosPoint = TMath::ACos(cosPoint);
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482 // DCA between daughters
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483 Double_t dca = v0->GetDcaV0Daughters();
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485 // Production vertex
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489 Double_t r = TMath::Sqrt(x*x + y*y);
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492 Double_t chi2ndf = kfMother->GetChi2()/kfMother->GetNDF();
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494 if(kfMother) delete kfMother;
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499 if(iMass < fK0cutInvMass[0] || iMass > fK0cutInvMass[1]) return kFALSE;
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501 if(chi2ndf > fK0cutChi2NDF) return kFALSE;
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503 if(cosPoint < fK0cutCosPoint[0] || cosPoint > fK0cutCosPoint[1]) return kFALSE;
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505 if(dca < fK0cutDCA[0] || dca > fK0cutDCA[1]) return kFALSE;
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507 if(r < fK0cutVertexR[0] || r > fK0cutVertexR[1]) return kFALSE;
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522 //____________________________________________________________________
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523 Bool_t AliESDv0KineCuts::CaseLambda(AliESDv0* const v0, Int_t &pdgV0, Int_t &pdgP, Int_t &pdgN, Int_t id) const {
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525 // process teh Lambda and Anti-Lambda candidate
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528 if(!v0) return kFALSE;
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530 const Double_t cL0mass=TDatabasePDG::Instance()->GetParticle(kLambda0)->Mass(); // PDG lambda mass
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532 AliVTrack* daughter[2];
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533 Int_t pIndex = 0, nIndex = 0;
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534 Float_t mMass[2] = {-1., -1.};
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535 Bool_t sign = CheckSigns(v0);
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537 pIndex = v0->GetPindex();
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538 nIndex = v0->GetNindex();
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539 mMass[0] = v0->GetEffMass(4, 2);
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540 mMass[1] = v0->GetEffMass(2, 4);
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543 pIndex = v0->GetNindex();
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544 nIndex = v0->GetPindex();
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545 mMass[0] = v0->GetEffMass(2, 4);
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546 mMass[1] = v0->GetEffMass(4, 2);
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549 daughter[0] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(pIndex));
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550 daughter[1] = dynamic_cast<AliVTrack *>(fEvent->GetTrack(nIndex));
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551 if(!daughter[0] || !daughter[1]) return kFALSE;
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553 AliKFParticle *kfMother[2] = {0x0, 0x0};
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555 kfMother[0] = CreateMotherParticle(daughter[0], daughter[1], TMath::Abs(kProton), TMath::Abs(kPiPlus));
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556 if(!kfMother[0]) return kFALSE;
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559 kfMother[1] = CreateMotherParticle(daughter[0], daughter[1], TMath::Abs(kPiPlus), TMath::Abs(kProton));
\r
560 if(!kfMother[1]) return kFALSE;
\r
562 Float_t dMass[2] = {TMath::Abs(mMass[0] - cL0mass), TMath::Abs(mMass[1] - cL0mass)};
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565 d[0] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(pIndex));
\r
566 d[1] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(nIndex));
\r
567 if(!d[0] || !d[1]) return kFALSE;
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569 Float_t p[2] = {d[0]->GetP(), d[1]->GetP()};
\r
571 // check the 3 lambda - antilambda variables
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572 Int_t check[2] = {-1, -1}; // 0 : lambda, 1 : antilambda
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573 // 1) momentum of the daughter particles - proton is expected to have higher momentum than pion
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574 check[0] = (p[0] > p[1]) ? 0 : 1;
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575 // 2) mass of the mother particle
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576 check[1] = (dMass[0] < dMass[1]) ? 0 : 1;
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578 // require positive correlation of (1) and (2)
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579 if(check[0] != check[1]){
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580 if(kfMother[0]) delete kfMother[0];
\r
581 if(kfMother[1]) delete kfMother[1];
\r
585 // now that the check[0] == check[1]
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586 const Int_t type = check[0];
\r
588 // require that the input armenteros preselection agree:
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589 if(type != id) return kFALSE;
\r
593 iMass = (type == 0) ? v0->GetEffMass(4, 2) : v0->GetEffMass(2, 4);
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596 iMass = (type == 0) ? v0->GetEffMass(2, 4) : v0->GetEffMass(4, 2);
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599 // cos pointing angle
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600 Double_t cosPoint = v0->GetV0CosineOfPointingAngle();
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601 cosPoint = TMath::ACos(cosPoint);
\r
603 // DCA between daughters
\r
604 Double_t dca = v0->GetDcaV0Daughters();
\r
606 // Production vertex
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609 Double_t r = TMath::Sqrt(x*x + y*y);
\r
611 // proton - pion indices
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612 Int_t ix[2] = {0, 1};
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619 Double_t chi2ndf = kfMother[type]->GetChi2()/kfMother[type]->GetNDF();
\r
621 if(kfMother[0]) delete kfMother[0];
\r
622 if(kfMother[1]) delete kfMother[1];
\r
628 if(iMass < fLcutInvMass[0] || iMass > fLcutInvMass[1]) return kFALSE;
\r
630 if(chi2ndf > fLcutChi2NDF) return kFALSE;
\r
632 if(cosPoint < fLcutCosPoint[0] || cosPoint > fLcutCosPoint[1]) return kFALSE;
\r
634 if(dca < fLcutDCA[0] || dca > fLcutDCA[1]) return kFALSE;
\r
636 if(r < fLcutVertexR[0] || r > fLcutVertexR[1]) return kFALSE;
\r
665 //____________________________________________________________________
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666 Bool_t AliESDv0KineCuts::V0CutsCommon(const AliESDv0 * const v0) const
\r
669 // V0 cuts common to all V0s
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672 AliESDtrack* dN, *dP;
\r
674 dP = dynamic_cast<AliESDtrack *>(fEvent->GetTrack(v0->GetPindex()));
\r
675 dN = dynamic_cast<AliESDtrack *>(fEvent->GetTrack(v0->GetNindex()));
\r
677 if(!dN || !dP) return kFALSE;
\r
679 Int_t qP = dP->Charge();
\r
680 Int_t qN = dN->Charge();
\r
682 if((qP*qN) != -1) return kFALSE;
\r
686 //____________________________________________________________________
\r
687 void AliESDv0KineCuts::Armenteros(AliESDv0* const v0, Float_t val[2]) const
\r
690 // computes the Armenteros variables for given V0
\r
691 // fills the histogram
\r
692 // returns the values via "val"
\r
695 Double_t mn[3] = {0,0,0};
\r
696 Double_t mp[3] = {0,0,0};
\r
697 Double_t mm[3] = {0,0,0};
\r
699 if(CheckSigns(v0)){
\r
700 v0->GetNPxPyPz(mn[0],mn[1],mn[2]); //reconstructed cartesian momentum components of negative daughter
\r
701 v0->GetPPxPyPz(mp[0],mp[1],mp[2]); //reconstructed cartesian momentum components of positive daughter
\r
704 v0->GetPPxPyPz(mn[0],mn[1],mn[2]); //reconstructed cartesian momentum components of negative daughter
\r
705 v0->GetNPxPyPz(mp[0],mp[1],mp[2]); //reconstructed cartesian momentum components of positive daughter
\r
707 v0->GetPxPyPz(mm[0],mm[1],mm[2]); //reconstructed cartesian momentum components of mother
\r
709 TVector3 vecN(mn[0],mn[1],mn[2]);
\r
710 TVector3 vecP(mp[0],mp[1],mp[2]);
\r
711 TVector3 vecM(mm[0],mm[1],mm[2]);
\r
713 Double_t thetaP = acos((vecP * vecM)/(vecP.Mag() * vecM.Mag()));
\r
714 Double_t thetaN = acos((vecN * vecM)/(vecN.Mag() * vecM.Mag()));
\r
716 Double_t alfa = ((vecP.Mag())*cos(thetaP)-(vecN.Mag())*cos(thetaN))/
\r
717 ((vecP.Mag())*cos(thetaP)+(vecN.Mag())*cos(thetaN)) ;
\r
718 Double_t qt = vecP.Mag()*sin(thetaP);
\r
723 //____________________________________________________________________
\r
724 Bool_t AliESDv0KineCuts::CheckSigns(AliESDv0* const v0) const
\r
727 // check wheter the sign was correctly applied to
\r
728 // V0 daughter tracks
\r
731 Bool_t correct = kFALSE;
\r
733 Int_t pIndex = 0, nIndex = 0;
\r
734 pIndex = v0->GetPindex();
\r
735 nIndex = v0->GetNindex();
\r
738 d[0] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(pIndex));
\r
739 d[1] = dynamic_cast<AliESDtrack*>(fEvent->GetTrack(nIndex));
\r
742 sign[0] = (int)d[0]->GetSign();
\r
743 sign[1] = (int)d[1]->GetSign();
\r
745 if(-1 == sign[0] && 1 == sign[1]){
\r
754 //________________________________________________________________
\r
755 Double_t AliESDv0KineCuts::PsiPair(AliESDv0* const v0) const
\r
758 // Angle between daughter momentum plane and plane
\r
761 if(!fEvent) return -1.;
\r
763 Float_t magField = fEvent->GetMagneticField();
\r
767 if(CheckSigns(v0)){
\r
768 pIndex = v0->GetPindex();
\r
769 nIndex = v0->GetNindex();
\r
772 pIndex = v0->GetNindex();
\r
773 nIndex = v0->GetPindex();
\r
777 AliESDtrack* daughter[2];
\r
779 daughter[0] = dynamic_cast<AliESDtrack *>(fEvent->GetTrack(pIndex));
\r
780 daughter[1] = dynamic_cast<AliESDtrack *>(fEvent->GetTrack(nIndex));
\r
783 v0->GetXYZ(x,y,z);//Reconstructed coordinates of V0; to be replaced by Markus Rammler's method in case of conversions!
\r
785 Double_t mn[3] = {0,0,0};
\r
786 Double_t mp[3] = {0,0,0};
\r
789 v0->GetNPxPyPz(mn[0],mn[1],mn[2]);//reconstructed cartesian momentum components of negative daughter;
\r
790 v0->GetPPxPyPz(mp[0],mp[1],mp[2]);//reconstructed cartesian momentum components of positive daughter;
\r
793 Double_t deltat = 1.;
\r
794 deltat = TMath::ATan(mp[2]/(TMath::Sqrt(mp[0]*mp[0] + mp[1]*mp[1])+1.e-13)) - TMath::ATan(mn[2]/(TMath::Sqrt(mn[0]*mn[0] + mn[1]*mn[1])+1.e-13));//difference of angles of the two daughter tracks with z-axis
\r
796 Double_t radiussum = TMath::Sqrt(x*x + y*y) + 50;//radius to which tracks shall be propagated
\r
798 Double_t momPosProp[3];
\r
799 Double_t momNegProp[3];
\r
801 AliExternalTrackParam pt(*daughter[0]), nt(*daughter[1]);
\r
803 Double_t psiPair = 4.;
\r
805 if(nt.PropagateTo(radiussum,magField) == 0)//propagate tracks to the outside
\r
807 if(pt.PropagateTo(radiussum,magField) == 0)
\r
809 pt.GetPxPyPz(momPosProp);//Get momentum vectors of tracks after propagation
\r
810 nt.GetPxPyPz(momNegProp);
\r
813 TMath::Sqrt(momNegProp[0]*momNegProp[0]+momNegProp[1]*momNegProp[1]+momNegProp[2]*momNegProp[2]);//absolute momentum value of negative daughter
\r
815 TMath::Sqrt(momPosProp[0]*momPosProp[0]+momPosProp[1]*momPosProp[1]+momPosProp[2]*momPosProp[2]);//absolute momentum value of positive daughter
\r
817 Double_t scalarproduct =
\r
818 momPosProp[0]*momNegProp[0]+momPosProp[1]*momNegProp[1]+momPosProp[2]*momNegProp[2];//scalar product of propagated positive and negative daughters' momenta
\r
820 Double_t chipair = TMath::ACos(scalarproduct/(pEle*pPos));//Angle between propagated daughter tracks
\r
822 psiPair = TMath::Abs(TMath::ASin(deltat/chipair));
\r
826 //___________________________________________________________________
\r
827 Bool_t AliESDv0KineCuts::GetConvPosXY(AliESDtrack * const ptrack, AliESDtrack * const ntrack, Double_t convpos[2]) const
\r
830 // recalculate the gamma conversion XY postition
\r
833 const Double_t b = fEvent->GetMagneticField();
\r
835 Double_t helixcenterpos[2];
\r
836 GetHelixCenter(ptrack,b,ptrack->Charge(),helixcenterpos);
\r
838 Double_t helixcenterneg[2];
\r
839 GetHelixCenter(ntrack,b,ntrack->Charge(),helixcenterneg);
\r
841 Double_t poshelix[6];
\r
842 ptrack->GetHelixParameters(poshelix,b);
\r
843 Double_t posradius = TMath::Abs(1./poshelix[4]);
\r
845 Double_t neghelix[6];
\r
846 ntrack->GetHelixParameters(neghelix,b);
\r
847 Double_t negradius = TMath::Abs(1./neghelix[4]);
\r
849 Double_t xpos = helixcenterpos[0];
\r
850 Double_t ypos = helixcenterpos[1];
\r
851 Double_t xneg = helixcenterneg[0];
\r
852 Double_t yneg = helixcenterneg[1];
\r
854 convpos[0] = (xpos*negradius + xneg*posradius)/(negradius+posradius);
\r
855 convpos[1] = (ypos*negradius+ yneg*posradius)/(negradius+posradius);
\r
859 //___________________________________________________________________
\r
860 Bool_t AliESDv0KineCuts::GetHelixCenter(AliESDtrack * const track, Double_t b,Int_t charge, Double_t center[2]) const
\r
863 // computes the center of the track helix
\r
866 Double_t pi = TMath::Pi();
\r
869 track->GetHelixParameters(helix,b);
\r
871 Double_t xpos = helix[5];
\r
872 Double_t ypos = helix[0];
\r
873 Double_t radius = TMath::Abs(1./helix[4]);
\r
874 Double_t phi = helix[2];
\r
881 Double_t xpoint = radius * TMath::Cos(phi);
\r
882 Double_t ypoint = radius * TMath::Sin(phi);
\r
889 /* avoid self assignment
\r
897 /* avoid self assignment
\r
908 center[0] = xpos + xpoint;
\r
909 center[1] = ypos + ypoint;
\r
913 //___________________________________________________________________
\r
914 AliKFParticle *AliESDv0KineCuts::CreateMotherParticle(const AliVTrack* const pdaughter, const AliVTrack* const ndaughter, Int_t pspec, Int_t nspec) const
\r
917 // Creates a mother particle
\r
919 AliKFParticle pkfdaughter(*pdaughter, pspec);
\r
920 AliKFParticle nkfdaughter(*ndaughter, nspec);
\r
923 // Create the mother particle
\r
924 AliKFParticle *m = new AliKFParticle(pkfdaughter, nkfdaughter);
\r
925 m->SetField(fEvent->GetMagneticField());
\r
926 if(TMath::Abs(kElectron) == pspec && TMath::Abs(kElectron) == nspec) m->SetMassConstraint(0, 0.001);
\r
927 else if(TMath::Abs(kPiPlus) == pspec && TMath::Abs(kPiPlus) == nspec) m->SetMassConstraint(TDatabasePDG::Instance()->GetParticle(kK0Short)->Mass(), 0.);
\r
928 else if(TMath::Abs(kProton) == pspec && TMath::Abs(kPiPlus) == nspec) m->SetMassConstraint(TDatabasePDG::Instance()->GetParticle(kLambda0)->Mass(), 0.);
\r
929 else if(TMath::Abs(kPiPlus) == pspec && TMath::Abs(kProton) == nspec) m->SetMassConstraint(TDatabasePDG::Instance()->GetParticle(kLambda0)->Mass(), 0.);
\r
931 AliErrorClass("Wrong daughter ID - mass constraint can not be set");
\r
934 AliKFVertex improvedVertex = *fPrimaryVertex;
\r
935 improvedVertex += *m;
\r
936 m->SetProductionVertex(improvedVertex);
\r
938 // update 15/06/2010
\r
939 // mother particle will not be added to primary vertex but only to its copy
\r
940 // as this confilcts with calling
\r
941 // m->SetPrimaryVertex() function and
\r
942 // subsequently removing the mother particle afterwards
\r
943 // Source: Sergey Gorbunov
\r
947 //____________________________________________________________________
\r
948 void AliESDv0KineCuts::SetEvent(AliESDEvent* const event){
\r
950 // direct setter of ESD event
\r
954 AliErrorClass("Invalid input event pointer");
\r
957 if (fUseExternalVertex) return;
\r
959 if(fPrimaryVertex && fDeleteVertex){
\r
960 delete fPrimaryVertex;
\r
961 fPrimaryVertex=0x0;
\r
963 fPrimaryVertex = new AliKFVertex(*(fEvent->GetPrimaryVertex()));
\r
964 fDeleteVertex=kTRUE;
\r
970 //____________________________________________________________________
\r
971 void AliESDv0KineCuts::SetEvent(AliVEvent* const event){
\r
973 // direct setter of ESD event
\r
976 fEvent = dynamic_cast<AliESDEvent*>(event);
\r
978 AliErrorClass("Invalid input event pointer");
\r
982 if (fUseExternalVertex) return;
\r
984 if(fPrimaryVertex && fDeleteVertex){
\r
985 delete fPrimaryVertex;
\r
986 fPrimaryVertex=0x0;
\r
988 fPrimaryVertex = new AliKFVertex(*(fEvent->GetPrimaryVertex()));
\r
989 fDeleteVertex=kTRUE;
\r
994 //________________________________________________________________
\r
995 void AliESDv0KineCuts::UseExternalVertex(Bool_t use_external){
\r
997 // Reenable primary Vertex from ESD event
\r
999 if (use_external) fUseExternalVertex =kTRUE;
\r
1000 else fUseExternalVertex =kFALSE;
\r
1006 //________________________________________________________________
\r
1007 void AliESDv0KineCuts::SetPrimaryVertex(AliKFVertex* const v){
\r
1009 // set the primary vertex of the event
\r
1011 if(fPrimaryVertex && fDeleteVertex){
\r
1012 delete fPrimaryVertex;
\r
1013 fPrimaryVertex =0x0;
\r
1014 fDeleteVertex = kFALSE;
\r
1016 fUseExternalVertex=kTRUE;
\r
1017 fPrimaryVertex = v; // set primary Vertex
\r
1018 if(!fPrimaryVertex){
\r
1019 AliErrorClass("Failed to initialize the primary vertex");
\r
1023 //___________________________________________________________________
\r
1024 void AliESDv0KineCuts::SetMode(Int_t mode, Int_t type){
\r
1026 // this function allows the user to select (prior running the 'ProcessV0' function)
\r
1027 // to select different approaches to V0 selection - the 'mode'
\r
1029 // different systems (pp, PbPb) - 'type'
\r
1031 // To see the cut values for different modes please refer to the
\r
1032 // function SetCuts()
\r
1034 // Important notice: based on the parameters particular sets of cuts will
\r
1035 // be activated for teh V0 selection. If some additional changes to single
\r
1036 // cuts are needed please us the SetXXXcut function (see the header file)
\r
1041 fMode = kPurity; // used to obtain highest purity possible - the efficiency may be low
\r
1044 fMode = kEffGamma; // used to obtain highes efficiency possible - the purity may be worse
\r
1047 AliError("V0 selection mode not recognozed, setting 'kPurity'");
\r
1053 fType = kPP; // cuts optimized for low multiplicity
\r
1056 fType = kPbPb; // cuts optimized for high multiplicity
\r
1060 // setup the cut values for selected mode & type
\r
1064 //___________________________________________________________________
\r
1065 void AliESDv0KineCuts::SetMode(Int_t mode, const char* type){
\r
1067 // overloaded function - please see above
\r
1072 if(!strcmp("pp", type)) t = kPP;
\r
1073 else if(!(strcmp("PbPb", type))) t = kPbPb;
\r
1075 AliError("data type not recognized, setting 'pp'");
\r
1082 //___________________________________________________________________
\r
1083 void AliESDv0KineCuts::SetCuts(){
\r
1085 // this funciton sets the default cut values based on the selected
\r
1086 // fMode and fType.
\r
1087 // please note that only the cuts that have different values than the default
\r
1088 // cuts are updated here
\r
1091 // last update: 14/02/2011
\r
1092 // as a very preliminary - the only change to default cuts is to apply
\r
1093 // less restricting gamma conversion selection in PreselectV0() function
\r