[PWGCF] Add dalitz plot for track-v0 analysis in femto framework (#15605)

Author: ariedel-cern

PWGCF/Femto/Core/femtoUtils.h

@@ -63,7 +63,7 @@ float itsSignal(T const& track)
   return static_cast<float>(signal);
 };
 
-inline double getMass(int pdgCode)
+inline double getPdgMass(int pdgCode)
 {
   // use this function instead of TDatabasePDG to return masses defined in the PhysicsConstants.h header
   // this approach saves a lot of memory and important partilces like deuteron are missing in TDatabasePDG anyway
@@ -119,7 +119,7 @@ inline double getMass(int pdgCode)
       mass = o2::constants::physics::MassOmegaMinus;
       break;
     default:
-      LOG(fatal) << "PDG code is not suppored";
+      LOG(warn) << "PDG code is not suppored. Return 0...";
   }
   return mass;
 }

PWGCF/Femto/Core/pairBuilder.h

@@ -34,6 +34,8 @@
 #include <Framework/HistogramSpec.h>
 #include <Framework/Logger.h>
 
+#include <TPDGCode.h>
+
 #include <chrono>
 #include <cstdint>
 #include <map>
@@ -595,13 +597,28 @@ class PairTrackV0Builder
     mTrackCleaner.init(confTrackCleaner);
     mV0Cleaner.init(confV0Cleaner);
 
+    int pdgCodePosDau = 0;
+    int pdgCodeNegDau = 0;
+    if (modes::isEqual(v0Type, modes::V0::kK0short)) {
+      pdgCodeNegDau = kPiPlus;
+      pdgCodeNegDau = kPiMinus;
+    } else if (modes::isEqual(v0Type, modes::V0::kLambda) || modes::isEqual(v0Type, modes::V0::kAntiLambda)) {
+      if (confV0Selection.sign.value > 0) {
+        pdgCodeNegDau = kProton;
+        pdgCodeNegDau = kPiMinus;
+      } else {
+        pdgCodeNegDau = kProtonBar;
+        pdgCodeNegDau = kPiPlus;
+      }
+    }
+
     mPairHistManagerSe.template init<mode>(registry, pairHistSpec, confPairBinning, confPairCuts);
-    mPairHistManagerSe.setMass(confTrackSelection.pdgCodeAbs.value, confV0Selection.pdgCodeAbs.value);
+    mPairHistManagerSe.setMass(confTrackSelection.pdgCodeAbs.value, 0, 0, confV0Selection.pdgCodeAbs.value, pdgCodePosDau, pdgCodeNegDau);
     mPairHistManagerSe.setCharge(confTrackSelection.chargeAbs.value, 1);
     mCprSe.init(registry, cprHistSpec, confCpr, confTrackSelection.chargeAbs.value);
 
     mPairHistManagerMe.template init<mode>(registry, pairHistSpec, confPairBinning, confPairCuts);
-    mPairHistManagerMe.setMass(confTrackSelection.pdgCodeAbs.value, confV0Selection.pdgCodeAbs.value);
+    mPairHistManagerMe.setMass(confTrackSelection.pdgCodeAbs.value, 0, 0, confV0Selection.pdgCodeAbs.value, pdgCodePosDau, pdgCodeNegDau);
     mPairHistManagerMe.setCharge(confTrackSelection.chargeAbs.value, 1);
     mCprMe.init(registry, cprHistSpec, confCpr, confTrackSelection.chargeAbs.value);
     mPc.template init<mode>(confPairCuts);