STEER/AOD/AliAODpidUtil.cxx

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   3  *                                                                        *
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  15
  16 /* $Id: AliAODpidUtil.cxx 38329 2010-01-17 19:17:24Z hristov $ */
  17
  18 //-----------------------------------------------------------------
  19 //           Implementation of the combined PID class
  20 //           For the AOD Class
  21 //           containing information on the particle identification
  22 //      Origin: Rosa Romita, GSI, r.romita@gsi.de
  23 //-----------------------------------------------------------------
  24
  25 #include "TRandom.h"
  26 #include "AliLog.h"
  27 #include "AliPID.h"
  28 #include "AliAODpidUtil.h"
  29 #include "AliAODEvent.h"
  30 #include "AliAODTrack.h"
  31 #include "AliAODPid.h"
  32 #include "AliTRDPIDResponse.h"
  33 #include "AliESDtrack.h"
  34 #include "AliAODMCHeader.h"
  35 #include "AliAODMCParticle.h"
  36
  37 #include <AliDetectorPID.h>
  38
  39 ClassImp(AliAODpidUtil)
  40
  41 //_________________________________________________________________________
  42 Float_t AliAODpidUtil::GetTPCsignalTunedOnData(const AliVTrack *t) const {
  43     AliAODTrack *track = (AliAODTrack *) t;
  44     Float_t dedx = track->GetTPCsignalTunedOnData();
  45     if(dedx > 0) return dedx;
  46
  47     dedx = t->GetTPCsignal();
  48     track->SetTPCsignalTunedOnData(dedx);
  49
  50     if(dedx < 20) return dedx;
  51
  52
  53     AliPID::EParticleType type = AliPID::kPion;
  54
  55     AliAODMCHeader *mcHeader = dynamic_cast<AliAODMCHeader*>(track->GetAODEvent()->GetList()->FindObject(AliAODMCHeader::StdBranchName()));
  56     if (mcHeader) {
  57         TClonesArray *mcArray = (TClonesArray*)track->GetAODEvent()->GetList()->FindObject(AliAODMCParticle::StdBranchName());
  58
  59         Bool_t kGood = kTRUE;
  60
  61         Int_t iS = TMath::Abs(((AliAODMCParticle*)mcArray->At(TMath::Abs(t->GetLabel())))->GetPdgCode());
  62         if(iS==AliPID::ParticleCode(AliPID::kElectron)){
  63             type = AliPID::kElectron;
  64         }
  65         else if(iS==AliPID::ParticleCode(AliPID::kMuon)){
  66             type = AliPID::kMuon;
  67         }
  68         else if(iS==AliPID::ParticleCode(AliPID::kPion)){
  69             type = AliPID::kPion;
  70         }
  71         else if(iS==AliPID::ParticleCode(AliPID::kKaon)){
  72             type = AliPID::kKaon;
  73         }
  74         else if(iS==AliPID::ParticleCode(AliPID::kProton)){
  75             type = AliPID::kProton;
  76         }
  77         else if(iS==AliPID::ParticleCode(AliPID::kDeuteron)){ // d
  78             type = AliPID::kDeuteron;
  79         }
  80         else if(iS==AliPID::ParticleCode(AliPID::kTriton)){ // t
  81             type = AliPID::kTriton;
  82         }
  83         else if(iS==AliPID::ParticleCode(AliPID::kHe3)){ // 3He
  84             type = AliPID::kHe3;
  85         }
  86         else if(iS==AliPID::ParticleCode(AliPID::kAlpha)){ // 4He
  87             type = AliPID::kAlpha;
  88         }
  89         else
  90             kGood = kFALSE;
  91
  92         if(kGood){
  93             //TODO maybe introduce different dEdxSources?
  94         Double_t bethe = fTPCResponse.GetExpectedSignal(track, type, AliTPCPIDResponse::kdEdxDefault, this->UseTPCEtaCorrection());
  95         Double_t sigma = fTPCResponse.GetExpectedSigma(track, type, AliTPCPIDResponse::kdEdxDefault, this->UseTPCEtaCorrection());
  96         dedx = gRandom->Gaus(bethe,sigma);
  97
  98             if(iS == AliPID::ParticleCode(AliPID::kHe3) || iS == AliPID::ParticleCode(AliPID::kAlpha)) dedx *= 5;
  99         }
 100
 101     }
 102
 103     track->SetTPCsignalTunedOnData(dedx);
 104     return dedx;
 105 }
 106 //_________________________________________________________________________
 107 Float_t AliAODpidUtil::GetNumberOfSigmasTOFold(const AliVParticle *vtrack, AliPID::EParticleType type) const
 108 {
 109   //
 110   // Number of sigma implementation for the TOF
 111   //
 112
 113   AliAODTrack *track=(AliAODTrack*)vtrack;
 114
 115   Bool_t oldAod=kTRUE;
 116   Double_t sigTOF;
 117   AliAODPid *pidObj = track->GetDetPid();
 118   if (!pidObj) return -999.;
 119   Double_t tofTime=pidObj->GetTOFsignal();
 120   Double_t expTime=fTOFResponse.GetExpectedSignal((AliVTrack*)vtrack,type);
 121   Double_t sigmaTOFPid[AliPID::kSPECIES];
 122   pidObj->GetTOFpidResolution(sigmaTOFPid);
 123   AliAODEvent *event=(AliAODEvent*)track->GetAODEvent();
 124   if (event) {  // protection if the user didn't call GetTrack, which sets the internal pointer
 125     AliTOFHeader* tofH=(AliTOFHeader*)event->GetTOFHeader();
 126     if (tofH && (TMath::Abs(sigmaTOFPid[0]) <= 1.E-16) ) { // new AOD
 127         sigTOF=fTOFResponse.GetExpectedSigma(track->P(),expTime,AliPID::ParticleMassZ(type)); //fTOFResponse is set in InitialiseEvent
 128         tofTime -= fTOFResponse.GetStartTime(vtrack->P());
 129         oldAod=kFALSE;
 130     }
 131   } else {
 132     AliError("pointer to AliAODEvent not found, please call GetTrack to set it");
 133     return -996.;
 134   }
 135   if (oldAod) { // old AOD
 136     if (type <= AliPID::kProton) {
 137       sigTOF=sigmaTOFPid[type];
 138     } else return -998.;  // light nuclei cannot be supported on old AOD because we don't have timeZero resolution
 139   }
 140   if (sigTOF>0) return (tofTime - expTime)/sigTOF;
 141   else return -997.;
 142 }