AOD: also keep particles marked as keepPhysics

DataFormats/simulation/include/SimulationDataFormat/MCUtils.h

@@ -33,6 +33,11 @@ class MCTrackNavigator
   /// (of which p needs to be a part itself). The container can be fetched via MCKinematicsReader.
   static bool isPhysicalPrimary(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
 
+  /// return true of particle is to be kept for physics analysis in any case
+  /// (follows logic used in particle stack class
+  static bool isKeepPhysics(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
+  static bool isFromPrimaryDecayChain(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer);
+
   // some convenience functions for navigation
 
   /// Given an MCTrack p; Return the first primary mother particle in the upward parent chain (follow

DataFormats/simulation/src/MCUtils.cxx

@@ -167,4 +167,44 @@ bool MCTrackNavigator::isPhysicalPrimary(o2::MCTrack const& p, std::vector<o2::M
   } // end else branch produced by generator
 }
 
+bool MCTrackNavigator::isFromPrimaryDecayChain(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer)
+{
+  /** check if the particle is from the
+      decay chain of a primary particle **/
+
+  /** check if from decay **/
+  if (p.getProcess() != kPDecay) {
+    return false;
+  }
+  /** check if mother is primary **/
+  auto mother = getMother(p, pcontainer);
+  if (!mother || mother->isPrimary()) {
+    return true;
+  }
+  /** else check if mother is from primary decay **/
+  return isFromPrimaryDecayChain(*mother, pcontainer);
+}
+
+bool MCTrackNavigator::isKeepPhysics(o2::MCTrack const& p, std::vector<o2::MCTrack> const& pcontainer)
+{
+  auto isFromPrimaryPairProduction = [&pcontainer](const MCTrack& part) {
+    /** check if the particle is from
+        pair production from a particle
+        belonging to the primary decay chain **/
+
+    /** check if from pair production **/
+    if (part.getProcess() != kPPair) {
+      return false;
+    }
+    auto mother = getMother(part, pcontainer);
+    if (!mother || mother->isPrimary()) {
+      return true;
+    }
+    /** else check if mother is from primary decay **/
+    return isFromPrimaryDecayChain(*mother, pcontainer);
+  };
+  //
+  return p.isPrimary() || isFromPrimaryPairProduction(p) || isFromPrimaryDecayChain(p, pcontainer);
+}
+
 } // namespace o2::mcutils

Detectors/AOD/src/AODProducerWorkflowSpec.cxx

@@ -55,6 +55,7 @@
 #include "SimulationDataFormat/MCEventLabel.h"
 #include "SimulationDataFormat/MCTrack.h"
 #include "SimulationDataFormat/MCTruthContainer.h"
+#include "SimulationDataFormat/MCUtils.h"
 #include "ZDCBase/Constants.h"
 #include "GPUTPCGMMergedTrackHit.h"
 #include "TOFBase/Utils.h"
@@ -636,6 +637,14 @@ void AODProducerWorkflowDPL::fillMCParticlesTable(o2::steer::MCKinematicsReader&
           mToStore[Triplet_t(source, event, particle)] = 1;
           continue;
         }
+        if (o2::mcutils::MCTrackNavigator::isPhysicalPrimary(mcParticles[particle], mcParticles)) {
+          mToStore[Triplet_t(source, event, particle)] = 1;
+          continue;
+        }
+        if (o2::mcutils::MCTrackNavigator::isKeepPhysics(mcParticles[particle], mcParticles)) {
+          mToStore[Triplet_t(source, event, particle)] = 1;
+          continue;
+        }
         if (mToStore.find(Triplet_t(source, event, particle)) == mToStore.end()) {
           continue;
         }