SVStudy: Add mc mother pdg code

Author: f3sch

Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/V0Ext.h

@@ -17,9 +17,7 @@
 #include "ReconstructionDataFormats/V0.h"
 #include "SimulationDataFormat/MCCompLabel.h"
 
-namespace o2
-{
-namespace dataformats
+namespace o2::dataformats
 {
 
 struct ProngInfoExt {
@@ -40,10 +38,10 @@ struct V0Ext {
   V0Index v0ID;
   std::array<ProngInfoExt, 2> prInfo{};
   const ProngInfoExt& getPrInfo(int i) const { return prInfo[i]; }
-  ClassDefNV(V0Ext, 1);
+  int mcPID = -1;
+  ClassDefNV(V0Ext, 2);
 };
 
-} // namespace dataformats
-} // namespace o2
+} // namespace o2::dataformats
 
 #endif

Detectors/GlobalTrackingWorkflow/study/src/SVStudy.cxx

@@ -22,6 +22,7 @@
 #include "DetectorsBase/GeometryManager.h"
 #include "SimulationDataFormat/MCEventLabel.h"
 #include "SimulationDataFormat/MCUtils.h"
+#include "SimulationDataFormat/MCTrack.h"
 #include "CommonDataFormat/BunchFilling.h"
 #include "CommonUtils/NameConf.h"
 #include "DataFormatsFT0/RecPoints.h"
@@ -86,7 +87,7 @@ class SVStudySpec : public Task
   float mBz = 0;
   GTrackID::mask_t mTracksSrc{};
   o2::vertexing::DCAFitterN<2> mFitterV0;
-  o2::steer::MCKinematicsReader mcReader; // reader of MC information
+  std::unique_ptr<o2::steer::MCKinematicsReader> mcReader; // reader of MC information
 };
 
 void SVStudySpec::init(InitContext& ic)
@@ -96,6 +97,9 @@ void SVStudySpec::init(InitContext& ic)
   mRefit = ic.options().get<bool>("refit");
   mSelK0 = ic.options().get<float>("sel-k0");
   mMaxEta = ic.options().get<float>("max-eta");
+  if (mUseMC) {
+    mcReader = std::make_unique<o2::steer::MCKinematicsReader>("collisioncontext.root");
+  }
 }
 
 void SVStudySpec::run(ProcessingContext& pc)
@@ -162,6 +166,7 @@ o2::dataformats::V0Ext SVStudySpec::processV0(int iv, o2::globaltracking::RecoCo
   }
   v0ext.v0ID = v0id;
   o2::MCCompLabel lb;
+  const o2::MCTrack* mcTrks[2];
   for (int ip = 0; ip < 2; ip++) {
     auto& prInfo = v0ext.prInfo[ip];
     auto gid = v0ext.v0ID.getProngID(ip);
@@ -218,6 +223,16 @@ o2::dataformats::V0Ext SVStudySpec::processV0(int iv, o2::globaltracking::RecoCo
         }
       }
     }
+    if (mUseMC) { // temp store of mctrks
+      mcTrks[ip] = mcReader->getTrack(lb);
+    }
+  }
+  if (mUseMC && (mcTrks[0] != nullptr) && (mcTrks[1] != nullptr)) {
+    // check majority vote on mother particle otherwise leave pdg -1
+    if (mcTrks[0]->getMotherTrackId() == mcTrks[1]->getMotherTrackId()) {
+      const auto mother = mcReader->getTrack(lb.getSourceID(), lb.getEventID(), mcTrks[0]->getMotherTrackId());
+      v0ext.mcPID = mother->GetPdgCode();
+    }
   }
   return v0ext;
 }