New Class HIJetConstituentModifier in HIJetRec

Reconstruction/HeavyIonRec/HIJetRec/HIJetRec/HIJetConstituentModifier.h

+// This file is -*- C++ -*-
+/*
+   Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+ */
+
+#ifndef HIJETREC_HIJETCONSTITUENTMODIFIER_H
+#define HIJETREC_HIJETCONSTITUENTMODIFIER_H
+ ///////////////////////////////////////////////////////
+ /// \class HIJetConstituentModifier
+ /// \author R.Longo - riccardo.longo@cern.ch
+ /// \date May 2020
+ ///
+ /// Tool to subtract final HIEventShape from constituents
+ /// on the fly (w/o modifying clusters)
+ ///////////////////////////////////////////////////////
+
+#include "JetRec/JetModifierBase.h"
+#include "xAODCaloEvent/CaloClusterContainer.h"
+
+#include "StoreGate/ReadHandleKey.h"
+#include "StoreGate/WriteHandleKey.h"
+
+class HIJetConstituentModifier : public JetModifierBase {
+
+   ASG_TOOL_CLASS(HIJetConstituentModifier, IJetModifier);
+
+ public:
+
+  // Constructor from tool name.
+  HIJetConstituentModifier(const std::string& myname);
+
+  virtual StatusCode initialize() override;
+  // Inherited method to modify a jet.
+  virtual int modifyJet(xAOD::Jet& jet) const;
+
+ private:
+   /// \brief Name of input cluster container
+  SG::ReadHandleKey< xAOD::CaloClusterContainer > m_clusterKey { this, "ClusterKey", "ClusterKey", "Name of the input Cluster Container"};
+
+};
+
+#endif

Reconstruction/HeavyIonRec/HIJetRec/Root/HIJetConstituentModifier.cxx

+/*
+  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+*/
+
+#include "HIJetRec/HIJetConstituentModifier.h"
+#include "HIJetRec/HIJetRecDefs.h"
+#include "xAODJet/JetConstituentVector.h"
+#include "xAODCaloEvent/CaloClusterContainer.h"
+#include "xAODBase/IParticle.h"
+#include "xAODBase/IParticleContainer.h"
+#include "JetRec/JetModifierBase.h"
+
+#include "StoreGate/ReadHandle.h"
+
+HIJetConstituentModifier::HIJetConstituentModifier(const std::string& myname): JetModifierBase(myname)
+{
+}
+
+StatusCode HIJetConstituentModifier::initialize(){
+
+  ATH_CHECK( m_clusterKey.initialize() );
+
+  return StatusCode::SUCCESS;
+}
+
+int HIJetConstituentModifier::modifyJet(xAOD::Jet& jet) const {
+
+    const xAOD::JetConstituentVector constituents = jet.getConstituents();
+    std::vector<size_t> cluster_indices;
+    cluster_indices.reserve(constituents.size());
+
+    for (auto citer = constituents.begin(); citer != constituents.end(); ++citer)
+    {
+      cluster_indices.push_back(citer->rawConstituent()->index());
+    }
+
+    /// The accessor for the cluster element links
+   static SG::AuxElement::Accessor< std::vector< ElementLink< xAOD::IParticleContainer > > >
+     constituentAcc( "constituentLinks" );
+   static SG::AuxElement::Accessor< std::vector< float> >
+     constituentWeightAcc( "constituentWeights" );
+
+   if( constituentAcc.isAvailable(jet) ) constituentAcc( jet ).resize(0);
+   if( constituentWeightAcc.isAvailable(jet) ) constituentWeightAcc( jet ).resize(0);
+
+   //save unsubtracted kinematics as moment if they don’t exist already...
+   jet.setJetP4(HIJetRec::unsubtractedJetState(),jet.jetP4());
+
+   xAOD::IParticle::FourMom_t subtrP4;
+   xAOD::JetFourMom_t jet4vec;
+   //need to add usual safety checks on cluster container access
+   SG::ReadHandle<xAOD::CaloClusterContainer> readHandleSubtractedClusters ( m_clusterKey );
+   const xAOD::CaloClusterContainer* ccl=readHandleSubtractedClusters.cptr();
+   for(auto index : cluster_indices)
+   {
+     auto cl=ccl->at(index);
+     jet.addConstituent(cl);
+     subtrP4=cl->p4(HIJetRec::subtractedClusterState());
+   }
+   jet4vec.SetCoordinates(subtrP4.Pt(),subtrP4.Eta(),subtrP4.Phi(),subtrP4.M());
+   jet.setJetP4(jet4vec);
+
+   return 0;
+}