adding a preslice to fix processMC error

Author: murioni

PWGLF/Tasks/Resonances/k892analysispbpb.cxx

@@ -662,7 +662,7 @@ struct K892analysispbpb {
 
         // MC
         if constexpr (IsMC && !IsRot) {
-
+	  
           if (!trk1.has_mcParticle() || !trk2.has_mcParticle())
             continue;
 
@@ -834,6 +834,8 @@ struct K892analysispbpb {
   Partition<TrackCandidates> posPitof = (aod::track::signed1Pt > static_cast<float>(0)) && (nabs(aod::pidtof::tofNSigmaPi) <= cMaxTOFnSigmaPion) && (nabs(aod::track::pt) > cMinPtTOF);
   Partition<TrackCandidates> negKatof = (aod::track::signed1Pt < static_cast<float>(0)) && (nabs(aod::pidtof::tofNSigmaKa) <= cMaxTOFnSigmaKaon) && (nabs(aod::track::pt) > cMinPtTOF);
 
+  Preslice<aod::Tracks> trackPerCollision = aod::track::collisionId;
+
   template <bool IsMC, bool IsMix, bool IsRot, bool IsRun2, typename CollisionType, typename TracksType>
   void callFillHistoswithPartitions(const CollisionType& collision1, const TracksType&, const CollisionType& collision2, const TracksType&)
   {
@@ -1095,9 +1097,8 @@ struct K892analysispbpb {
   }
   PROCESS_SWITCH(K892analysispbpb, processEvtLossSigLossMC, "Process Signal Loss, Event Loss", false);
 
-  void processMC(aod::McCollisions::iterator const& /*mcCollision*/, aod::McParticles const& mcParticles, const soa::SmallGroups<EventCandidatesMCrec>& recCollisions, TrackCandidatesMCrec const& RecTracks)
+  void processMC(aod::McCollisions::iterator const&, aod::McParticles const& mcParticles, const soa::SmallGroups<EventCandidatesMCrec>& recCollisions, TrackCandidatesMCrec const& RecTracks)
   {
-
     histos.fill(HIST("QAevent/hMCrecCollSels"), 0);
     if (recCollisions.size() == 0) {
       histos.fill(HIST("QAevent/hMCrecCollSels"), 1);
@@ -1109,16 +1110,17 @@ struct K892analysispbpb {
     }
     for (const auto& RecCollision : recCollisions) {
       histos.fill(HIST("QAevent/hMCrecCollSels"), 3);
-
+   
       if (!myEventSelections(RecCollision))
         continue;
 
       histos.fill(HIST("QAevent/hMCrecCollSels"), 8);
       auto centrality = RecCollision.centFT0C();
       histos.fill(HIST("QAevent/hMultiplicityPercentMC"), centrality);
 
-      auto tracks = RecTracks.sliceByCached(aod::track::collisionId, RecCollision.globalIndex(), cache);
+      auto tracks = RecTracks.sliceBy(trackPerCollision, RecCollision.globalIndex());
 
+ 
       //            <IsMC, IsMix, IsRot, IsRun2>
       fillHistograms<true, false, false, false>(RecCollision, tracks, tracks);
 
@@ -1192,7 +1194,7 @@ struct K892analysispbpb {
 
       auto centrality = RecCollision.centRun2V0M();
       histos.fill(HIST("QAevent/hMultiplicityPercentMC"), centrality);
-      auto tracks = RecTracks.sliceByCached(aod::track::collisionId, RecCollision.globalIndex(), cache);
+      auto tracks = RecTracks.sliceBy(trackPerCollision, RecCollision.globalIndex());
 
       //            <IsMC, IsMix, IsRot, IsRun2>
       fillHistograms<true, false, false, true>(RecCollision, tracks, tracks);