DiTauTruthMatchingTool.cxx

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// Local include(s)
#include "TauAnalysisTools/DiTauTruthMatchingTool.h"
 
using namespace TauAnalysisTools;
 
//=================================PUBLIC-PART==================================
//______________________________________________________________________________
DiTauTruthMatchingTool::DiTauTruthMatchingTool( const std::string& name )
  : BuildTruthTaus(name)
  , m_accPtVis("pt_vis")
  , m_accEtaVis("eta_vis")
  , m_accPhiVis("phi_vis")
  , m_accMVis("m_vis")
{
}
 
//______________________________________________________________________________
DiTauTruthMatchingTool::~DiTauTruthMatchingTool( )
{
 
}
 
//______________________________________________________________________________
StatusCode DiTauTruthMatchingTool::initialize()
{
  ATH_MSG_INFO( "Initializing DiTauTruthMatchingTool" );
 
  // configure BuildTruthTaus in truth matching mode, not truth tau building mode
  DiTauTruthMatchingTool::BuildTruthTaus::setTruthMatchingMode();
 
  if (DiTauTruthMatchingTool::BuildTruthTaus::initialize().isFailure())
    {
      ATH_MSG_FATAL("Failed initializing BuildTruthTaus");
      return StatusCode::FAILURE;
    }
  return StatusCode::SUCCESS;
}
 
//______________________________________________________________________________
void DiTauTruthMatchingTool::getTruth(const xAOD::DiTauJet& xDiTau)
{
  if (retrieveTruthTaus().isFailure())
    return;
 
  if (findTruthTau(xDiTau).isFailure())
    ATH_MSG_WARNING("There was a failure in finding the matched truth tau");
 
  return;
}
 
//______________________________________________________________________________
void DiTauTruthMatchingTool::getTruth(const std::vector<const xAOD::DiTauJet*>& vDiTaus)
{
  for (auto xDiTau : vDiTaus)
    getTruth(*xDiTau);
  return;
}
 

//                                 Private Part                               //
 
//______________________________________________________________________________
StatusCode DiTauTruthMatchingTool::findTruthTau(const xAOD::DiTauJet& xDiTau)
{
  // check if decorations were already added to the first passed tau
  if (!m_bIsTruthMatchedAvailable.isValid()) {
    static const SG::ConstAccessor<char> accIsTruthMatched("IsTruthMatched");
    m_bIsTruthMatchedAvailable.set (accIsTruthMatched.isAvailable(xDiTau));
  }
  if (*m_bIsTruthMatchedAvailable.ptr())
    return StatusCode::SUCCESS;
 
  if (m_bTruthTauAvailable)
    return checkTruthMatch(xDiTau, *m_truthTausEvent.m_xTruthTauContainerConst);
  else
    return checkTruthMatch(xDiTau, *m_truthTausEvent.m_xTruthTauContainer);
}
 
//______________________________________________________________________________
StatusCode DiTauTruthMatchingTool::checkTruthMatch (const xAOD::DiTauJet& xDiTau, const xAOD::TruthParticleContainer& xTruthTauContainer) const
{
  std::vector<const xAOD::TruthParticle*> vTruthMatch;
  std::vector<TruthMatchedParticleType> vTruthMatchedParticleType;
  std::vector<const xAOD::Jet*> vTruthJetMatch;
 
 
  xAOD::TruthParticleContainer xRemainingTruthTaus = xTruthTauContainer;
 
  static const SG::Decorator<char> decIsTruthMatched("IsTruthMatched");
  static const SG::Decorator<char> decIsTruthHadronic("IsTruthHadronic");
  static const SG::ConstAccessor<int> accNSubjets("n_subjets");
  static const SG::ConstAccessor<char> accIsTruthHadronic("IsTruthHadronic");
 
  int n_subjets = 0; 
  if(!(accNSubjets.isAvailable(xDiTau))){
    // n_subjets decoration is not available, recalculation on the fly
    while (xDiTau.subjetPt(n_subjets) > 0. )
    {
      n_subjets++;
    }
  } else {
    n_subjets = accNSubjets(xDiTau);      
  }   
 
  // set default values for each subjet
  for (int i = 0; i < n_subjets; ++i)
    {
      const xAOD::TruthParticle* xTruthMatch = nullptr;
      TruthMatchedParticleType eTruthMatchedParticleType = Unknown;
 
      vTruthMatch.push_back(xTruthMatch);
      vTruthMatchedParticleType.push_back(eTruthMatchedParticleType);
 
      const xAOD::Jet* xTruthJetMatch = nullptr;
      vTruthJetMatch.push_back(xTruthJetMatch);
    }
 
  // truthmatching for subjets:
  for (int i = 0; i < n_subjets; ++i)
    {
      TLorentzVector vSubjetTLV;
      vSubjetTLV.SetPtEtaPhiE(xDiTau.subjetPt(i),
                  xDiTau.subjetEta(i),
                  xDiTau.subjetPhi(i),
                  xDiTau.subjetE(i));
      if ( truthMatch(vSubjetTLV,
              xRemainingTruthTaus,
              vTruthMatch.at(i),
              vTruthJetMatch.at(i),
              vTruthMatchedParticleType.at(i)).isFailure() )
    {
      ATH_MSG_WARNING("There was a failure in matching truth taus with subjet " << i);
      return StatusCode::FAILURE;
    }
      if (vTruthMatch.at(i) && vTruthMatchedParticleType.at(i) == TruthHadronicTau)
    {
      xRemainingTruthTaus.erase( std::find(xRemainingTruthTaus.begin(),
                           xRemainingTruthTaus.end(),
                           vTruthMatch.at(i)) );
    }
    }
 
  // create links for jets
  std::vector< ElementLink < xAOD::JetContainer > > vTruthJetLinks;
  for (int i = 0; i < n_subjets; ++i)
  {
      const xAOD::Jet* xTruthJetMatch = vTruthJetMatch.at(i); 
      if(xTruthJetMatch){
          ElementLink < xAOD::JetContainer > lTruthParticleLink(xTruthJetMatch, *m_truthTausEvent.m_xTruthJetContainerConst);
          vTruthJetLinks.push_back(lTruthParticleLink);
      }
      else
      {
          ElementLink < xAOD::JetContainer > lTruthParticleLink;
          vTruthJetLinks.push_back(lTruthParticleLink);
      }    
  }
  static const SG::Decorator<std::vector<ElementLink<xAOD::JetContainer>>>
    decTruthJetLinks ("truthJetLinks");
  decTruthJetLinks(xDiTau) = std::move(vTruthJetLinks);
 
 
  bool bTruthMatched = true;
 
  // create link to the original TruthParticle
  std::vector< ElementLink < xAOD::TruthParticleContainer > > vTruthLinks;
  for (int i = 0; i < n_subjets; ++i)
    {
      const xAOD::TruthParticle* xTruthMatch = vTruthMatch.at(i);
      TruthMatchedParticleType eTruthMatchedParticleType = vTruthMatchedParticleType.at(i);
      if (xTruthMatch)
    {
      if (eTruthMatchedParticleType == TruthHadronicTau)
        {
          ElementLink < xAOD::TruthParticleContainer > lTruthParticleLink(xTruthMatch, xTruthTauContainer);
          vTruthLinks.push_back(lTruthParticleLink);  
        }
      else if (eTruthMatchedParticleType == TruthMuon)
        {
          ElementLink <xAOD::TruthParticleContainer> lTruthParticleLink(xTruthMatch, *m_truthTausEvent.m_xTruthMuonContainerConst);
          vTruthLinks.push_back(lTruthParticleLink);
        }
      else if (eTruthMatchedParticleType  == TruthElectron)
        {
          ElementLink <xAOD::TruthParticleContainer> lTruthParticleLink(xTruthMatch, *m_truthTausEvent.m_xTruthElectronContainerConst);
          vTruthLinks.push_back(lTruthParticleLink);
        }
    }
      else
    {
      ElementLink < xAOD::TruthParticleContainer > lTruthParticleLink;
      vTruthLinks.push_back(lTruthParticleLink);  
 
      // ditau is not truth matched if one of the two leading subjets is not truth matched
      if (i == 0 || i == 1) bTruthMatched = false;
    }
    }
 
  static const SG::Decorator<std::vector<ElementLink<xAOD::TruthParticleContainer>>>
    decTruthParticleLinks ("truthParticleLinks");
  decTruthParticleLinks(xDiTau) = vTruthLinks;
  if (!m_bTruthTauAvailable)
    {
      static const SG::Decorator<std::vector<ElementLink<xAOD::TruthParticleContainer>>>
        decTruthTaus ("TruthTaus");
      decTruthTaus(xDiTau) = vTruthLinks;
    }
 
  static const SG::Decorator<float> decTruthLeadPt("TruthVisLeadPt");
  static const SG::Decorator<float> decTruthLeadEta("TruthVisLeadEta");
  static const SG::Decorator<float> decTruthLeadPhi("TruthVisLeadPhi");
  static const SG::Decorator<float> decTruthLeadM("TruthVisLeadM");
  static const SG::Decorator<int> decTruthLeadPdgID("TruthLeadPdgID");
  static const SG::Decorator<float> decTruthSubleadPt("TruthVisSubleadPt");
  static const SG::Decorator<float> decTruthSubleadEta("TruthVisSubleadEta");
  static const SG::Decorator<float> decTruthSubleadPhi("TruthVisSubleadPhi");
  static const SG::Decorator<float> decTruthSubleadM("TruthVisSubleadM");
  static const SG::Decorator<int> decTruthSubleadPdgID("TruthSubleadPdgID");
  static const SG::Decorator<float> decTruthDeltaR("TruthVisDeltaR");
  static const SG::Decorator<float> decTruthMass("TruthVisMass");
 
  // the ditau candidate should have at least 2 subjets to be truth matched
  if ( n_subjets < 2) {
    decIsTruthMatched(xDiTau) = (char)false;
    decIsTruthHadronic(xDiTau) = (char)false;
    decTruthLeadPt(xDiTau) = -1234.;
    decTruthLeadEta(xDiTau) = -1234.;
    decTruthLeadPhi(xDiTau) = -1234.;
    decTruthLeadM(xDiTau) = -1234.;
    decTruthLeadPdgID(xDiTau) = -1234.;
    decTruthSubleadPt(xDiTau) = -1234.;
    decTruthSubleadEta(xDiTau) = -1234.;
    decTruthSubleadPhi(xDiTau) = -1234.;
    decTruthSubleadM(xDiTau) = -1234.;
    decTruthSubleadPdgID(xDiTau) = -1234.;
    decTruthDeltaR(xDiTau) = -1234.;
    decTruthMass(xDiTau) = -1234.;
    return StatusCode::SUCCESS;
  }
 
  decIsTruthMatched(xDiTau) = (char)bTruthMatched;
  if (bTruthMatched)
    {
      // ditau is hadronic if two leading subjets are truth matched with hadronic decay
      decIsTruthHadronic(xDiTau) = (char)(vTruthMatchedParticleType[0]==TruthHadronicTau
                      && vTruthMatchedParticleType[1]==TruthHadronicTau );
    }
  else 
    decIsTruthHadronic(xDiTau) = (char)false;
 
  if (accIsTruthHadronic(xDiTau))
    {
      TLorentzVector tlvTruthTau1;
      TLorentzVector tlvTruthTau2;
      tlvTruthTau1.SetPtEtaPhiM(m_accPtVis(*(*vTruthLinks.at(0))),
                m_accEtaVis(*(*vTruthLinks.at(0))),
                m_accPhiVis(*(*vTruthLinks.at(0))),
                m_accMVis(*(*vTruthLinks.at(0))));
      tlvTruthTau2.SetPtEtaPhiM(m_accPtVis(*(*vTruthLinks.at(1))),
                m_accEtaVis(*(*vTruthLinks.at(1))),
                m_accPhiVis(*(*vTruthLinks.at(1))),
                m_accMVis(*(*vTruthLinks.at(1))));
 
      decTruthLeadPt(xDiTau) = std::max(tlvTruthTau1.Pt(), tlvTruthTau2.Pt());
      decTruthLeadEta(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau1.Eta() : tlvTruthTau2.Eta();
      decTruthLeadPhi(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau1.Phi() : tlvTruthTau2.Phi();
      decTruthLeadM(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau1.M() : tlvTruthTau2.M();
      decTruthLeadPdgID(xDiTau) = (*vTruthLinks.at(0))->pdgId();
      decTruthSubleadPt(xDiTau) = std::min(tlvTruthTau1.Pt(), tlvTruthTau2.Pt());
      decTruthSubleadEta(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau2.Eta() : tlvTruthTau1.Eta();
      decTruthSubleadPhi(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau2.Phi() : tlvTruthTau1.Phi();
      decTruthSubleadM(xDiTau) = (tlvTruthTau1.Pt() > tlvTruthTau2.Pt()) ? tlvTruthTau2.M() : tlvTruthTau1.M();
      decTruthSubleadPdgID(xDiTau) = (*vTruthLinks.at(1))->pdgId();
      decTruthDeltaR(xDiTau) = tlvTruthTau1.DeltaR(tlvTruthTau2);
      decTruthMass(xDiTau) = (tlvTruthTau1 + tlvTruthTau2).M();
    }
  else {
      // set to a default value       
      decTruthLeadPt(xDiTau) = -1234.; 
      decTruthLeadEta(xDiTau) = -1234.;
      decTruthLeadPhi(xDiTau) = -1234.;
      decTruthLeadM(xDiTau) = -1234.;
      decTruthLeadPdgID(xDiTau) = -1234.;
      decTruthSubleadPt(xDiTau) = -1234.;
      decTruthSubleadEta(xDiTau) = -1234.; 
      decTruthSubleadPhi(xDiTau) = -1234.;
      decTruthSubleadM(xDiTau) = -1234.;
      decTruthSubleadPdgID(xDiTau) = -1234.;
      decTruthDeltaR(xDiTau) = -1234.;
      decTruthMass(xDiTau) = -1234.; 
    }     
  
  return StatusCode::SUCCESS;
}
//______________________________________________________________________________
StatusCode DiTauTruthMatchingTool::truthMatch(const TLorentzVector& vSubjetTLV,
                                              const xAOD::TruthParticleContainer& xTruthTauContainer,
                                              const xAOD::TruthParticle* &xTruthMatch,
                          const xAOD::Jet* &xTruthJetMatch,
                                              TruthMatchedParticleType &eTruthMatchedParticleType) const
{
  for (auto xTruthTauIt : xTruthTauContainer)
    {
      TLorentzVector vTruthVisTLV;
      vTruthVisTLV.SetPtEtaPhiM(m_accPtVis(*xTruthTauIt),
                m_accEtaVis(*xTruthTauIt),
                m_accPhiVis(*xTruthTauIt),
                m_accMVis(*xTruthTauIt));
      if (vSubjetTLV.DeltaR(vTruthVisTLV) <= m_dMaxDeltaR)
    {
      static const SG::ConstAccessor<char> accIsHadronicTau("IsHadronicTau");
      if (static_cast<bool>(accIsHadronicTau(*xTruthTauIt)))
        eTruthMatchedParticleType = TruthHadronicTau;
      else
        continue; // don't let leptonic taus steal truthmatch just by chance
 
      xTruthMatch = xTruthTauIt;
      break;
    }
    }
 
  if (!xTruthMatch and m_truthTausEvent.m_xTruthMuonContainerConst)
    {
      double dPtMax = 0.;
      for (auto xTruthMuonIt : *m_truthTausEvent.m_xTruthMuonContainerConst)
    {
      if (vSubjetTLV.DeltaR(xTruthMuonIt->p4()) <= m_dMaxDeltaR)
        {
          if (xTruthMuonIt->pt()<dPtMax)
        continue;
          eTruthMatchedParticleType = TruthMuon;
 
          xTruthMatch = xTruthMuonIt;
          dPtMax = xTruthMuonIt->pt();
        }
    }
    }
 
  if (!xTruthMatch and m_truthTausEvent.m_xTruthElectronContainerConst)
    {
      double dPtMax = 0.;
      for (auto xTruthElectronIt : *m_truthTausEvent.m_xTruthElectronContainerConst)
    {
      if (vSubjetTLV.DeltaR(xTruthElectronIt->p4()) <= m_dMaxDeltaR)
        {
          if (xTruthElectronIt->pt()<dPtMax)
        continue;
          eTruthMatchedParticleType = TruthElectron;
          xTruthMatch = xTruthElectronIt;
          dPtMax = xTruthElectronIt->pt();
        }
    }
    }
 
  if (m_truthTausEvent.m_xTruthJetContainerConst)
  {
    double dPtMax = 0.;
    for (auto xTruthJetIt : *m_truthTausEvent.m_xTruthJetContainerConst)
    {
      if (vSubjetTLV.DeltaR(xTruthJetIt->p4()) <= m_dMaxDeltaR)
      {
        if (xTruthJetIt->pt()<dPtMax)
          continue;
        xTruthJetMatch = xTruthJetIt;
        dPtMax = xTruthJetIt->pt();
      }
    }
  }
 
  return StatusCode::SUCCESS;
}