Truth.cxx

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/*
  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
*/
 
// This source file implements all of the functions related to Truth
// in the SUSYObjDef_xAOD class
 
// Local include(s):
#include "SUSYTools/SUSYObjDef_xAOD.h"
 
// For using the MCTruthClassifier definitions
#include "MCTruthClassifier/MCTruthClassifierDefs.h"
 
#include "TruthUtils/MagicNumbers.h"
#include "TruthUtils/HepMCHelpers.h"
 
#ifndef XAOD_STANDALONE // For now metadata is Athena-only
#include "AthAnalysisBaseComps/AthAnalysisHelper.h"
#endif
 
namespace ST {
 
 
bool SUSYObjDef_xAOD :: isPrompt(const xAOD::IParticle* part) const {
 
  const int type  = acc_truthType(*part);
  int origin      = acc_truthOrigin(*part);
  int originbkg   = 0;
  if(acc_bkgTruthOrigin.isAvailable(*part)){ //only in SUSY2,3,5 for the moment!
    originbkg = acc_bkgTruthOrigin(*part);
  }
  else{
    ATH_MSG_DEBUG("::isPrompt() : No bkgTruthOrigin decoration available. Returning false by default.");
    return false;
  }
 
  //Electrons 
  if( part->type() == xAOD::Type::Electron ){ 
    switch(type){
    case MCTruthPartClassifier::BkgElectron:
      if(origin != MCTruthPartClassifier::PhotonConv) return false;
      if(originbkg == MCTruthPartClassifier::FSRPhot || originbkg == MCTruthPartClassifier::BremPhot) return true;
      origin = originbkg;
      /* FALLTHRU */
    case MCTruthPartClassifier::IsoElectron:
      return (origin == MCTruthPartClassifier::top
          || origin == MCTruthPartClassifier::WBoson
          || origin == MCTruthPartClassifier::ZBoson
          || origin == MCTruthPartClassifier::Higgs
          || origin == MCTruthPartClassifier::HiggsMSSM
          || origin == MCTruthPartClassifier::HeavyBoson
          || origin == MCTruthPartClassifier::WBosonLRSM
          || origin == MCTruthPartClassifier::NuREle
          || origin == MCTruthPartClassifier::NuRMu
          || origin == MCTruthPartClassifier::NuRTau
          || origin == MCTruthPartClassifier::LQ
          || origin == MCTruthPartClassifier::SUSY);
    default:
      return false;
    }
    // NB: will classify a few muon/quark brems as prompt electrons, but a small effect
  }
  if( part->type() == xAOD::Type::Muon ){ 
    return (type == MCTruthPartClassifier::IsoMuon);
  }
  else{
    ATH_MSG_DEBUG("::isPrompt() : Only Electrons supported at the moment!");
  }
 
  //Photons ... ?
  //Taus ... ?
  return false;
}
 
 
StatusCode SUSYObjDef_xAOD::FindSusyHP(int& pdgid1, int& pdgid2) const {
 
  const xAOD::TruthParticleContainer* truthP = nullptr;
  bool isTruth3 = false;
  std::string key_T1 = "TruthParticles"; 
  std::string key_T3 = "TruthBSM";
 
  ATH_MSG_DEBUG("Contains " << key_T1 << ": " << ((evtStore()->contains<xAOD::TruthParticleContainer>( key_T1 ))?1:0));
  ATH_MSG_DEBUG("Contains " << key_T3 << ": " << ((evtStore()->contains<xAOD::TruthParticleContainer>( key_T3 ))?1:0));
 
  if(evtStore()->contains<xAOD::TruthParticleContainer>( key_T1 )){
    ATH_CHECK( evtStore()->retrieve(truthP, key_T1) );
    ATH_MSG_DEBUG("Retrieved " << key_T1 << " : size = " << truthP->size());
    if (truthP->empty()) { ATH_MSG_WARNING(key_T1 << " is empty. Skipping FindSusyHP."); return StatusCode::SUCCESS; }
  }
  else if(evtStore()->contains<xAOD::TruthParticleContainer>( key_T3 )){
    isTruth3=true;    
    ATH_CHECK( evtStore()->retrieve(truthP, key_T3) );
    ATH_MSG_DEBUG("Retrieved " << key_T3 << " : size = " << truthP->size());
    if (truthP->empty()) { ATH_MSG_WARNING(key_T3 << " is empty. Skipping FindSusyHP."); return StatusCode::SUCCESS; }
  }
  else {
    ATH_MSG_WARNING("Neither " << key_T1 << " nor " << key_T3 << " are avaible. Skipping FindSusyHP.");
    return StatusCode::SUCCESS;
  }
 
  return SUSYObjDef_xAOD::FindSusyHP(truthP, pdgid1, pdgid2, isTruth3);
}
 
 
StatusCode SUSYObjDef_xAOD::FindSusyHP(const xAOD::TruthParticleContainer *truthP, int& pdgid1, int& pdgid2, bool isTruth3) const {
  if (!truthP) {
    ATH_MSG_ERROR("Null TruthParticleContainer pointer!!");
    return StatusCode::FAILURE;
  }
  if (truthP->empty()) {
    ATH_MSG_ERROR("Empty TruthParticleContainer!!");
    return StatusCode::FAILURE;
  }
  if ( !SUSYObjDef_xAOD::FindSusyHardProc(truthP, pdgid1, pdgid2, isTruth3) ) {
    ATH_MSG_ERROR("Problem finding SUSY hard process");
    return StatusCode::FAILURE;
  }
  if (pdgid1 == 0 || pdgid2 == 0) {
    ATH_MSG_DEBUG("No sparticles found!");
  }
  return StatusCode::SUCCESS;
}
 
 
bool SUSYObjDef_xAOD::FindSusyHardProc(const xAOD::TruthParticleContainer *truthP, int& pdgid1, int& pdgid2, bool isTruth3) {
 
  pdgid1 = 0;
  pdgid2 = 0;
 
  //check for TRUTH3 structure first
  if(isTruth3){
    if(!truthP || truthP->size()<2){
      return false;
    }
    
    //get ID of first two BSM particles
    pdgid1 = (*truthP)[0]->pdgId();
    pdgid2 = (*truthP)[1]->pdgId();
    return true;
  }
 
  //go for TRUTH1-like if not...
  const xAOD::TruthParticle* firstsp(nullptr);
  const xAOD::TruthParticle* secondsp(nullptr);
 
  if (!truthP || truthP->empty()) {
    return false;
  }
  for (const xAOD::TruthParticle* tp : *truthP) {
    if (MC::isSquark(tp) || MC::isSlepton(tp) || MC::isGaugino(tp)) {
 
      if (tp->nParents() != 0) {
 
        if ( !MC::isSUSY(tp->parent(0))) {
          if (!firstsp) {
            firstsp = tp;
          } else if (!secondsp) {
            secondsp = tp;
          } else {
            if (firstsp->nChildren() != 0 && HepMC::is_same_particle(tp,firstsp->child(0))) {
              firstsp = tp;
            }
            else if (secondsp->nChildren() != 0 && HepMC::is_same_particle(tp,secondsp->child(0))) {
              secondsp = tp;
            }
            else if (firstsp->nChildren() != 0 && HepMC::is_same_particle(firstsp->child(0),secondsp)) {
              firstsp = secondsp;
              secondsp = tp;
            }
            else if (secondsp->nChildren() != 0 && HepMC::is_same_particle(secondsp->child(0),firstsp)) {
              secondsp = firstsp;
              firstsp = tp;
            }
          }
        }
      }
    }
  }
 
  // quit if no sparticles found
  if (!firstsp && !secondsp) return true; // should find none or two
 
  if (firstsp->nChildren() == 1) {
    for (const xAOD::TruthParticle* tp : *truthP) {
      if (HepMC::is_same_particle(tp,firstsp->child(0)) && tp->pdgId() != firstsp->pdgId()) {
        firstsp = tp;
        break;
      }
    }
  }
 
  if (secondsp->nChildren() == 1) {
    for (const xAOD::TruthParticle* tp : *truthP) {
      if (HepMC::is_same_particle(tp,secondsp->child(0)) && tp->pdgId() != secondsp->pdgId()) {
        secondsp = tp;
        break;
      }
    }
  }
 
  if (MC::isSUSY(firstsp)) pdgid1 = firstsp->pdgId();
  if (MC::isSUSY(secondsp)) pdgid2 = secondsp->pdgId();
 
  // Return gracefully:
  return true;
}
 
 
StatusCode SUSYObjDef_xAOD::FindSusyHP(const xAOD::TruthEvent *truthE, int& pdgid1, int& pdgid2) const {
 
  if (!truthE) {
    ATH_MSG_ERROR("Null TruthEvent pointer!!");
    return StatusCode::FAILURE;
  }
  if ( !SUSYObjDef_xAOD::FindSusyHardProc(truthE, pdgid1, pdgid2) ) {
    ATH_MSG_ERROR("Problem finding SUSY hard process");
    return StatusCode::FAILURE;
  }
  if (pdgid1 == 0 || pdgid2 == 0) {
    ATH_MSG_DEBUG("No sparticles found!");
  }
  return StatusCode::SUCCESS;
}
 
 
bool SUSYObjDef_xAOD::FindSusyHardProc(const xAOD::TruthEvent *truthE, int& pdgid1, int& pdgid2) {
 
  pdgid1 = 0;
  pdgid2 = 0;
 
  //go for TRUTH1-like ...
  const xAOD::TruthParticle* firstsp(nullptr);
  const xAOD::TruthParticle* secondsp(nullptr);
 
  for (unsigned int p=0; p < truthE->nTruthParticles(); ++p){
 
    const xAOD::TruthParticle* tp = truthE->truthParticle(p);
 
    //check ifSUSY particle
    if (MC::isSquark(tp) || MC::isSlepton(tp) || MC::isGaugino(tp)) {
 
      if (tp->nParents() != 0) {
        if ( !MC::isSUSY(tp->parent(0))) {
          if (!firstsp) {
            firstsp = tp;
          } else if (!secondsp) {
            secondsp = tp;
          } else {
            if (firstsp->nChildren() != 0 && HepMC::is_same_particle(tp,firstsp->child(0))) {
              firstsp = tp;
            }
            else if (secondsp->nChildren() != 0 && HepMC::is_same_particle(tp,secondsp->child(0))) {
              secondsp = tp;
            }
            else if (firstsp->nChildren() != 0 && HepMC::is_same_particle(firstsp->child(0),secondsp)) {
              firstsp = secondsp;
              secondsp = tp;
            }
            else if (secondsp->nChildren() != 0 && HepMC::is_same_particle(secondsp->child(0),firstsp)) {
              secondsp = firstsp;
              firstsp = tp;
            }
          }
        }
      }
    }
  }
 
  // quit if no sparticles found
  if (!firstsp && !secondsp) return true; // should find none or two
  
  if (firstsp->nChildren() == 1) {
    for (unsigned int p=0; p < truthE->nTruthParticles(); ++p){
      const xAOD::TruthParticle* tp = truthE->truthParticle(p);
      if (HepMC::is_same_particle(tp,firstsp->child(0)) && tp->pdgId() != firstsp->pdgId()) {
        firstsp = tp;
        break;
      }
    }
  }
 
  if (secondsp->nChildren() == 1) {
    for (unsigned int p=0; p < truthE->nTruthParticles(); ++p){
      const xAOD::TruthParticle* tp = truthE->truthParticle(p);
      if (HepMC::is_same_particle(tp,secondsp->child(0)) && tp->pdgId() != secondsp->pdgId()) {
        secondsp = tp;
        break;
      }
    }
  }
 
  if (MC::isSUSY(firstsp)) pdgid1 = firstsp->pdgId();
  if (MC::isSUSY(secondsp)) pdgid2 = secondsp->pdgId();
 
  // Return gracefully:
  return true;
}
 
 
bool SUSYObjDef_xAOD::IsTruthBJet(const xAOD::Jet& input) const {
  //Method to set correctly the IsBjet decoration needed by the JetUncertainties tool
  bool isBjet = false;
  if (acc_signal(input)) {
 
    int truthlabel(-1);
    if (!input.getAttribute("HadronConeExclTruthLabelID", truthlabel)) {
      ATH_MSG_ERROR("Failed to get jet truth label!");
    }
 
    isBjet = std::abs(truthlabel) == 5;
  }
 
  const static SG::Decorator<char> dec_bjet_jetunc("bjet_jetunc"); //added for JetUncertainties usage
  dec_bjet_jetunc(input) = isBjet;
 
  return isBjet;
}
 
}