Add ghost merging alg

This MR adds a new algorithm to JetAnalysisAlgorithms which combines multiple ghost track collections into one. This is useful to combine standard and LRT ghost tracks to be used by downstream algorithms.

Tagging @dguest who may be interested

PhysicsAnalysis/Algorithms/JetAnalysisAlgorithms/Root/JetGhostMergingAlg.cxx

@@ -20,23 +20,25 @@
 
 namespace CP
 {
-  JetGhostMuonAssociationAlg ::
-  JetGhostMuonAssociationAlg (const std::string& name, 
-                              ISvcLocator* pSvcLocator)
+  JetGhostMergingAlg ::
+  JetGhostMergingAlg (const std::string& name, 
+                      ISvcLocator* pSvcLocator)
     : AnaAlgorithm (name, pSvcLocator)
   {
   }
 
-  StatusCode JetGhostMuonAssociationAlg :: 
+  StatusCode JetGhostMergingAlg :: 
   initialize ()
   {
     ANA_CHECK (m_jetLocation.initialize ());
     return StatusCode::SUCCESS;
   }
 
-  StatusCode JetGhostMuonAssociationAlg :: 
+  StatusCode JetGhostMergingAlg :: 
   execute ()
   {
+    const EventContext &ctx = Gaudi::Hive::currentContext();
+
     SG::ReadHandle<xAOD::JetContainer> inputJets(m_jetLocation,ctx);
     if (!inputJets.isValid()) {
         ATH_MSG_FATAL("No jet collection with name " << m_jetLocation.key() << " found in StoreGate!");
@@ -47,7 +49,7 @@ namespace CP
 
     for(const xAOD::Jet *jet: *inputJets) {
         std::vector<ElementLink<xAOD::IParticleContainer>> mergedGhosts;
-        for (const auto& ghostName: m_ghostTrackNames) {
+        for (const auto& ghostName: m_inputGhostTrackNames) {
             static const SG::AuxElement::ConstAccessor<std::vector<ElementLink<DataVector<xAOD::IParticle> > > > ghostTrackAcc(ghostName);
             const std::vector< ElementLink<DataVector<xAOD::IParticle> > > &ghosts = ghostTrackAcc( *jet );
             mergedGhosts.insert(mergedGhosts.end(), ghosts.begin(), ghosts.end());