AliAnalysisTaskChargedParticlesRef.cxx

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 * Author: The ALICE Off-line Project.                                    *
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#include <algorithm>
#include <array>
#include <functional>
#include <iostream>
#include <map>

#include <TMath.h>
#include <THistManager.h>
#include <TLinearBinning.h>

#include "AliAnalysisDataContainer.h"
#include "AliAnalysisManager.h"
#include "AliAnalysisUtils.h"
#include "AliAODInputHandler.h"
#include "AliAODTrack.h"
#include "AliEmcalAnalysisFactory.h"
#include "AliEMCALGeometry.h"
#include "AliEMCALRecoUtils.h"
#include "AliEMCALTriggerPatchInfo.h"
#include "AliEmcalTrackSelection.h"
#include "AliESDtrackCuts.h"
#include "AliESDEvent.h"
#include "AliInputEventHandler.h"
#include "AliPIDResponse.h"
#include "AliTOFPIDResponse.h"
#include "AliVEvent.h"
#include "AliVEventHandler.h"
#include "AliVVertex.h"

#include "AliEMCalTriggerExtraCuts.h"
#include "AliAnalysisTaskChargedParticlesRef.h"

ClassImp(EMCalTriggerPtAnalysis::AliAnalysisTaskChargedParticlesRef)

namespace EMCalTriggerPtAnalysis {

AliAnalysisTaskChargedParticlesRef::AliAnalysisTaskChargedParticlesRef() :
    AliAnalysisTaskEmcalTriggerBase(),
    fTrackCuts(nullptr),
    fYshift(0.465),
    fEtaSign(1),
    fMinPt(0.1),
    fEtaLabCut(-0.5, 0.5),
    fEtaCmsCut(-2., 2.),
    fPhiCut(0., TMath::TwoPi()),
    fStudyPID(false),
    fStudyEMCALgeo(false),
    fEnableSumw2(false)
{
}

AliAnalysisTaskChargedParticlesRef::AliAnalysisTaskChargedParticlesRef(const char *name) :
    AliAnalysisTaskEmcalTriggerBase(name),
    fTrackCuts(nullptr),
    fYshift(0.465),
    fEtaSign(1),
    fMinPt(0.1),
    fEtaLabCut(-0.5, 0.5),
    fEtaCmsCut(-2., 2.),
    fPhiCut(0., TMath::TwoPi()),
    fStudyPID(false),
    fStudyEMCALgeo(false),
    fEnableSumw2(false)
{
  SetNeedEmcalGeom(true);
  SetCaloTriggerPatchInfoName("EmcalTriggers");
}

AliAnalysisTaskChargedParticlesRef::~AliAnalysisTaskChargedParticlesRef() {
  //if(fTrackCuts) delete fTrackCuts;
}

void AliAnalysisTaskChargedParticlesRef::CreateUserObjects(){
  if(!fTrackCuts) InitializeTrackCuts("standard", fInputHandler->IsA() == AliAODInputHandler::Class());
  fTrackCuts->SaveQAObjects(fOutput);
}

void AliAnalysisTaskChargedParticlesRef::CreateUserHistos() {

  PtBinning newbinning;
  TString optionstring = fEnableSumw2 ? "s" : "";

  TLinearBinning etabinning(64, -0.8, 0.8), phibinning(100, 0., 2*TMath::Pi()), chargebinning(2, -1.5, 1.5);
  const TBinning *binning4D[4] = {&newbinning, &etabinning, &phibinning, &chargebinning};

  // Binning for the PID histogram
  const int kdimPID = 3;
  const int knbinsPID[kdimPID] = {1000, 200, 300};
  const double kminPID[kdimPID] = {-100., 0.,  0.}, kmaxPID[kdimPID] = {100., 200., 1.5};
  for(auto trg : GetSupportedTriggers()){
    fHistos->CreateTH1("hEventCount" + trg, "Event Counter for trigger class " + trg, 1, 0.5, 1.5, optionstring);
    fHistos->CreateTH1("hVertexBefore" + trg, "Vertex distribution before z-cut for trigger class " + trg, 500, -50, 50, optionstring);
    fHistos->CreateTH1("hVertexAfter" + trg, "Vertex distribution after z-cut for trigger class " + trg, 100, -10, 10, optionstring);


    fHistos->CreateTHnSparse("hPtEtaPhiAll" + trg, "p_{t}-#eta-#phi distribution of all accepted tracks for trigger " + trg + " ; p_{t} (GeV/c); #eta; #phi; charge", 4, binning4D, optionstring);
    fHistos->CreateTHnSparse("hPtEtaPhiCent" + trg, "p_{t}-#eta-#phi distribution of all accepted tracks for trigger " + trg + "; p_{t} (GeV/c); #eta; #phi; charge", 4, binning4D, optionstring);
    if(fStudyEMCALgeo) {
      fHistos->CreateTHnSparse("hPtEtaPhiEMCALAll" + trg, "p_{t}-#eta-#phi distribution of all accepted tracks pointing to the EMCAL for trigger " + trg + "; p_{t} (GeV/c); #eta; #phi; charge", 4, binning4D, optionstring);
      fHistos->CreateTHnSparse("hPtEtaPhiEMCALCent" + trg, "p_{t}-#eta-#phi distribution of all accepted tracks pointing to the EMCAL for trigger " + trg + "; p_{t} (GeV/c); #eta; #phi; charge", 4, binning4D, optionstring);
    }

    if(fStudyPID){
      fHistos->CreateTH2(Form("hTPCdEdxEMCAL%s", trg.Data()), Form("TPC dE/dx of charged particles in the EMCAL region for trigger %s", trg.Data()), 400, -20., 20., 200, 0., 200., optionstring);
      fHistos->CreateTH2(Form("hTOFBetaEMCAL%s", trg.Data()), Form("TOF beta  of charged particles in the EMCAL region for trigger %s", trg.Data()), 400, -20., 20., 150, 0., 1.5, optionstring);
      fHistos->CreateTHnSparse(Form("hPIDcorrEMCAL%s", trg.Data()), Form("Correlation of PID observables for Trigger %s", trg.Data()), kdimPID, knbinsPID, kminPID, kmaxPID, optionstring);
    }
  }
}

Bool_t AliAnalysisTaskChargedParticlesRef::Run() {
  Bool_t hasPIDresponse = fInputHandler->GetPIDResponse() != nullptr;
  if(fStudyPID && !hasPIDresponse) AliErrorStream() << "PID requested but PID response not available" << std::endl;

  // Loop over tracks, fill select particles
  // Histograms
  // - Full eta_{lab} (-0.8, 0.8), new binning
  // - Full eta_{lab} (-0.8, 0.8), old binning
  // - Eta distribution for tracks above 1, 2, 5, 10 GeV/c without eta cut
  // - Central eta_{cms} (-0.3, -0.2), new binning,
  // - Central eta_{cms} (-0.8, -0.2), old binning,
  // - Eta distribution for tracks above 1, 2, 5, 10 GeV/c
  // - Eta distribution for tracks above 1, 2, 5, 10 GeV/c with eta cut
  AliVTrack *checktrack(nullptr);
  int ptmin[5] = {1,2,5,10,20}; // for eta distributions
  Bool_t isEMCAL(kFALSE);
  Double_t etaEMCAL(0.), phiEMCAL(0.);
  for(int itrk = 0; itrk < fInputEvent->GetNumberOfTracks(); ++itrk){
    checktrack = dynamic_cast<AliVTrack *>(fInputEvent->GetTrack(itrk));
    if(!checktrack) continue;
    if(!fEtaLabCut.IsInRange(checktrack->Eta())) continue;
    if(!fPhiCut.IsInRange(checktrack->Phi())) continue;
    if(TMath::Abs(checktrack->Pt()) < fMinPt) continue;

    if(fStudyEMCALgeo){
      if(checktrack->IsA() == AliESDtrack::Class()){
        AliESDtrack copytrack(*(static_cast<AliESDtrack *>(checktrack)));
        AliEMCALRecoUtils::ExtrapolateTrackToEMCalSurface(&copytrack);
        etaEMCAL = copytrack.GetTrackEtaOnEMCal();
        phiEMCAL = copytrack.GetTrackPhiOnEMCal();
      } else {
        AliAODTrack copytrack(*(static_cast<AliAODTrack *>(checktrack)));
        AliEMCALRecoUtils::ExtrapolateTrackToEMCalSurface(&copytrack);
        etaEMCAL = copytrack.GetTrackEtaOnEMCal();
        phiEMCAL = copytrack.GetTrackPhiOnEMCal();
      }
      Int_t supermoduleID = -1;
      isEMCAL = fGeom->SuperModuleNumberFromEtaPhi(etaEMCAL, phiEMCAL, supermoduleID);
      // Exclude supermodules 10 and 11 as they did not participate in the trigger
      isEMCAL = isEMCAL && supermoduleID < 10;
    }

    // Calculate eta in cms frame according
    // EPJC74 (2014) 3054:
    // eta_cms = - eta_lab - |yshift|
    Double_t etacent = -1. * checktrack->Eta() - TMath::Abs(fYshift);
    etacent *= fEtaSign;

    if(!fEtaCmsCut.IsInRange(etacent)) continue;    // Apply eta-cent cut
    if(!fTrackCuts->IsTrackAccepted(checktrack)) continue;

    // Charge separation
    bool posCharge = checktrack->Charge() > 0;

    for(const auto &t : fSelectedTriggers){
      FillTrackHistos(t, posCharge, checktrack->Pt(), checktrack->Eta() * fEtaSign, etacent, checktrack->Phi(), isEMCAL);
      if(fStudyPID && hasPIDresponse)
        if(isEMCAL) FillPIDHistos(t, *checktrack);
    }
  }
  return true;
}

void AliAnalysisTaskChargedParticlesRef::UserFillHistosBeforeEventSelection(){
  // Apply vertex z cut
  for(const auto &t : fSelectedTriggers){
    Double_t weight = GetTriggerWeight(t);
    fHistos->FillTH1(Form("hVertexBefore%s", t.Data()), fVertex[2], weight);
  }
}

void AliAnalysisTaskChargedParticlesRef::UserFillHistosAfterEventSelection(){
  for(const auto &t : fSelectedTriggers) {
    Double_t weight = GetTriggerWeight(t);
    // Fill Event counter and reference vertex distributions after event selection
    fHistos->FillTH1(Form("hEventCount%s", t.Data()), 1, weight);
    fHistos->FillTH1(Form("hVertexAfter%s", t.Data()), fVertex[2], weight);
  }
}

void AliAnalysisTaskChargedParticlesRef::FillTrackHistos(
    const TString &eventclass,
    Bool_t posCharge,
    Double_t pt,
    Double_t etalab,
    Double_t etacent,
    Double_t phi,
    Bool_t inEmcal
    )
{
  Double_t weight = GetTriggerWeight(eventclass);
  AliDebugStream(1) << GetName() << ": Using weight " << weight << " for trigger " << eventclass << " in particle histograms." << std::endl;
  double kinepointall[4] = {TMath::Abs(pt), etalab, phi, posCharge ? 1. : -1.}, kinepointcent[4] = {TMath::Abs(pt), etacent, phi, posCharge ? 1. : -1.};
  fHistos->FillTHnSparse("hPtEtaPhiAll" + eventclass, kinepointall, weight);
  fHistos->FillTHnSparse("hPtEtaPhiCent" + eventclass, kinepointcent, weight);
  if(fStudyEMCALgeo && inEmcal){
    fHistos->FillTHnSparse("hPtEtaPhiEMCALAll" + eventclass, kinepointall, weight);
    fHistos->FillTHnSparse("hPtEtaPhiEMCALCent" + eventclass, kinepointall, weight);
  }
}

void AliAnalysisTaskChargedParticlesRef::FillPIDHistos(
    const TString &eventclass,
    const AliVTrack &trk
) {
  Double_t weight = GetTriggerWeight(eventclass);
  AliDebugStream(1) << GetName() << ": Using weight " << weight << " for trigger " << eventclass << " in PID histograms." << std::endl;
  AliPIDResponse *pid = fInputHandler->GetPIDResponse();
  if(TMath::Abs(trk.Eta()) > 0.5) return;
  if(!((trk.GetStatus() & AliVTrack::kTOFout) && (trk.GetStatus() & AliVTrack::kTIME))) return;

  double poverz = TMath::Abs(trk.P())/static_cast<double>(trk.Charge());
  fHistos->FillTH2("hTPCdEdxEMCAL" + eventclass, poverz, trk.GetTPCsignal(), weight);
  // correct for units - TOF in ps, track length in cm
  Double_t trtime = (trk.GetTOFsignal() - pid->GetTOFResponse().GetTimeZero()) * 1e-12;
  Double_t v = trk.GetIntegratedLength()/(100. * trtime);
  Double_t beta =  v / TMath::C();
  fHistos->FillTH2("hTOFBetaEMCAL" + eventclass, poverz, beta, weight);
  double datapoint[3] = {poverz, trk.GetTPCsignal(), beta};
  fHistos->FillTHnSparse("hPIDcorrEMCAL" + eventclass, datapoint, weight);
}

void AliAnalysisTaskChargedParticlesRef::InitializeTrackCuts(TString cutname, bool isAOD){
  SetEMCALTrackSelection(AliEmcalAnalysisFactory::TrackCutsFactory(cutname, isAOD));
}

AliAnalysisTaskChargedParticlesRef *AliAnalysisTaskChargedParticlesRef::AddTaskChargedParticlesRef(const TString &suffix){
  AliAnalysisManager *mgr = AliAnalysisManager::GetAnalysisManager();

  TString taskname = "chargedParticleQA_" + suffix;

  AliAnalysisTaskChargedParticlesRef *task = new AliAnalysisTaskChargedParticlesRef(taskname);
  mgr->AddTask(task);

  TString outfile(mgr->GetCommonFileName());
  outfile += ":ChargedParticleQA_" + suffix;
  TString containername = "TrackResults_" + suffix;

  task->ConnectInput(0, mgr->GetCommonInputContainer());
  mgr->ConnectOutput(task, 1, mgr->CreateContainer(containername.Data(), TList::Class(), AliAnalysisManager::kOutputContainer, outfile.Data()));

  return task;
}

AliAnalysisTaskChargedParticlesRef *AliAnalysisTaskChargedParticlesRef::AddTaskChargedParticlesRefDefault(const TString &cutname){
  AliAnalysisManager *mgr = AliAnalysisManager::GetAnalysisManager();

  AliAnalysisTaskChargedParticlesRef *task = new AliAnalysisTaskChargedParticlesRef("chargedParticleQA");
  mgr->AddTask(task);

  // Set Energy thresholds for additional patch selection:
  // These are events with offline patches of a given type where the trigger reached already the plateau
  // These numers are determined as:
  // EMC7: 5 GeV
  // EG1:  14 GeV
  // EG2:  8 GeV
  // EJ1:  22 GeV
  // EJ2:  12 GeV
  mgr->AddTask(task);
  task->SetOfflineTriggerSelection(
      EMCalTriggerPtAnalysis::AliEmcalAnalysisFactory::TriggerSelectionFactory(5, 14, 8, 22, 12)
  );
  task->SetEMCALTrackSelection(
      EMCalTriggerPtAnalysis::AliEmcalAnalysisFactory::TrackCutsFactory(
          cutname,
          mgr->GetInputEventHandler()->IsA() == AliAODInputHandler::Class()
      )
  );

  TString outfile(mgr->GetCommonFileName());
  outfile += ":ChargedParticleQA_%s" + cutname;

  task->ConnectInput(0, mgr->GetCommonInputContainer());
  mgr->ConnectOutput(task, 1, mgr->CreateContainer(Form("TrackResults_%s", cutname.Data()), TList::Class(), AliAnalysisManager::kOutputContainer, outfile.Data()));

  return task;
}

AliAnalysisTaskChargedParticlesRef::PtBinning::PtBinning():
    TCustomBinning()
{
  this->SetMinimum(0.);
  this->AddStep(1, 0.05);
  this->AddStep(2, 0.1);
  this->AddStep(4, 0.2);
  this->AddStep(7, 0.5);
  this->AddStep(16, 1);
  this->AddStep(36, 2);
  this->AddStep(40, 4);
  this->AddStep(50, 5);
  this->AddStep(100, 10);
  this->AddStep(200, 20);
}

} /* namespace EMCalTriggerPtAnalysis */