Merge pull request #33491 from rmanzoni/from-CMSSW_12_0_X_2021-04-19-…

…2300 Consider charge conjugation in decay products in PythiaFilterMultiAncestor
cms-sw · Apr 27, 2021 · c635404 · c635404
2 parents 4112ef6 + 3f2f8ce
commit c635404
Showing 1 changed file with 14 additions and 1 deletion.
diff --git a/GeneratorInterface/GenFilters/plugins/PythiaFilterMultiAncestor.cc b/GeneratorInterface/GenFilters/plugins/PythiaFilterMultiAncestor.cc
@@ -181,6 +181,7 @@ bool PythiaFilterMultiAncestor::filter(edm::StreamID, edm::Event& iEvent, const
           // use a counter, if there's enough daughters that match the pdg and kinematic
           // criteria accept the event
           uint good_dau = 0;
+          uint good_dau_cc = 0;
           for (HepMC::GenVertex::particle_iterator dau = (*p)->end_vertex()->particles_begin(HepMC::children);
                dau != (*p)->end_vertex()->particles_end(HepMC::children);
                ++dau) {
@@ -198,9 +199,21 @@ bool PythiaFilterMultiAncestor::filter(edm::StreamID, edm::Event& iEvent, const
                   continue;
                 ++good_dau;
               }
+              // check charge conjugation
+              if (-(*dau)->pdg_id() == daughterIDs[i]) {  // notice minus sign
+                if ((*dau)->momentum().perp() < daughterMinPts[i])
+                  continue;
+                if ((*dau)->momentum().perp() > daughterMaxPts[i])
+                  continue;
+                if ((*dau)->momentum().eta() < daughterMinEtas[i])
+                  continue;
+                if ((*dau)->momentum().eta() > daughterMaxEtas[i])
+                  continue;
+                ++good_dau_cc;
+              }
             }
           }
-          if (good_dau < daughterIDs.size())
+          if (good_dau < daughterIDs.size() && good_dau_cc < daughterIDs.size())
             accepted = false;
         }
       }