[PWGDQ] add qa for number of pairs per event in pairing (#15468)

Co-authored-by: ypwangg <ypwangg@mail.ustc.edu.cn>
Co-authored-by: ALICE Action Bot <alibuild@cern.ch>

Author: 3 people

PWGDQ/Core/HistogramsLibrary.cxx

@@ -42,7 +42,7 @@ void o2::aod::dqhistograms::DefineHistograms(HistogramManager* hm, const char* h
     hm->AddHistogram(histClass, "TF_NMFTs", "Number of MFT tracks per TF", false, 1000, 0.0, 200000.0, VarManager::kTFNMFTs);
   }
   if (!groupStr.CompareTo("event")) {
-    if (!subGroupStr.Contains("generator")) {
+    if (!subGroupStr.Contains("generator") && !subGroupStr.Contains("pairing")) {
       hm->AddHistogram(histClass, "VtxZ", "Vtx Z", false, 60, -15.0, 15.0, VarManager::kVtxZ);
       hm->AddHistogram(histClass, "VtxZ_Run", "Vtx Z", true, 1, -0.5, 0.5, VarManager::kRunNo, 60, -15.0, 15.0, VarManager::kVtxZ, 1, 0, 1, VarManager::kNothing, "", "", "", VarManager::kNothing, VarManager::kNothing, false, true);
       hm->AddHistogram(histClass, "BC", "Event per BC", false, 3564, 0.0, 3564.0, VarManager::kBCOrbit);
@@ -583,6 +583,14 @@ void o2::aod::dqhistograms::DefineHistograms(HistogramManager* hm, const char* h
       hm->AddHistogram(histClass, "FracAbove500um_NTracksTRD", "Fraction of tracks with DCAz > 500 um vs number of tracks with TRD", false, 100, 0.0, 1000.0, VarManager::kMultNTracksHasTRD, 100, 0.0, 1.0, VarManager::kDCAzFracAbove500um);
       hm->AddHistogram(histClass, "FracAbove5mm_NTracksTRD", "Fraction of tracks with DCAz > 5 mm vs number of tracks with TRD", false, 100, 0.0, 1000.0, VarManager::kMultNTracksHasTRD, 100, 0.0, 1.0, VarManager::kDCAzFracAbove5mm);
     }
+    if (subGroupStr.Contains("pairing")) {
+      if (subGroupStr.Contains("sameevent")) {
+        hm->AddHistogram(histClass, "NPairsPerEvent", "Number of track pairs per event", false, 100, 0.0, 100.0, VarManager::kNPairsPerEvent);
+      }
+      if (subGroupStr.Contains("mixedevent")) {
+        hm->AddHistogram(histClass, "NPairsPerEvent", "Number of track pairs per event", false, 500, 0.0, 500.0, VarManager::kNPairsPerEvent);
+      }
+    }
   } // end "event"
 
   if (!groupStr.CompareTo("two-collisions")) {

PWGDQ/Core/VarManager.cxx

@@ -1435,6 +1435,8 @@ void VarManager::SetDefaultVarNames()
   fgVariableUnits[kR3SP] = "";
   fgVariableNames[kR3EP] = "R_{3}^{EP} ";
   fgVariableUnits[kR3EP] = "";
+  fgVariableNames[kNPairsPerEvent] = "number of pairs per event";
+  fgVariableUnits[kNPairsPerEvent] = "";
   fgVariableNames[kPairMass] = "mass";
   fgVariableUnits[kPairMass] = "GeV/c2";
   fgVariableNames[kPairMassDau] = "mass dilepton";
@@ -2065,6 +2067,7 @@ void VarManager::SetDefaultVarNames()
   fgVarNamesMap["kTwoR2SP2"] = kTwoR2SP2;
   fgVarNamesMap["kTwoR2EP1"] = kTwoR2EP1;
   fgVarNamesMap["kTwoR2EP2"] = kTwoR2EP2;
+  fgVarNamesMap["kNPairsPerEvent"] = kNPairsPerEvent;
   fgVarNamesMap["kNEventWiseVariables"] = kNEventWiseVariables;
   fgVarNamesMap["kX"] = kX;
   fgVarNamesMap["kY"] = kY;

PWGDQ/Core/VarManager.h

@@ -480,10 +480,11 @@ class VarManager : public TObject
     kV2ME_EP,
     kWV2ME_SP,
     kWV2ME_EP,
-    kTwoR2SP1, // Scalar product resolution of event1 for ME technique
-    kTwoR2SP2, // Scalar product resolution of event2 for ME technique
-    kTwoR2EP1, // Event plane resolution of event2 for ME technique
-    kTwoR2EP2, // Event plane resolution of event2 for ME technique
+    kTwoR2SP1,       // Scalar product resolution of event1 for ME technique
+    kTwoR2SP2,       // Scalar product resolution of event2 for ME technique
+    kTwoR2EP1,       // Event plane resolution of event2 for ME technique
+    kTwoR2EP2,       // Event plane resolution of event2 for ME technique
+    kNPairsPerEvent, // number of pairs per event in same-event or mixed-event pairing
 
     // Variables for event mixing with cumulant
     kV22m,

PWGDQ/Tasks/tableReader_withAssoc.cxx

@@ -1326,6 +1326,7 @@ struct AnalysisSameEventPairing {
   int fNCutsBarrel;
   int fNCutsMuon;
   int fNPairCuts;
+  int fNPairPerEvent;
 
   bool fEnableBarrelMixingHistos;
   bool fEnableBarrelHistos;
@@ -1641,6 +1642,12 @@ struct AnalysisSameEventPairing {
       fHistMan->SetDefaultVarNames(VarManager::fgVariableNames, VarManager::fgVariableUnits);
       VarManager::SetCollisionSystem((TString)fConfigOptions.collisionSystem, fConfigOptions.centerMassEnergy); // set collision system and center of mass energy
       DefineHistograms(fHistMan, histNames.Data(), fConfigAddSEPHistogram.value.data());                        // define all histograms
+      if (fEnableBarrelHistos) {
+        DefineHistograms(fHistMan, "PairingSEQA", "sameevent-pairing"); // histograms for QA of the pairing
+      };
+      if (fEnableBarrelMixingHistos) {
+        DefineHistograms(fHistMan, "PairingMEQA", "mixedevent-pairing"); // histograms for QA of the pairing
+      };
       dqhistograms::AddHistogramsFromJSON(fHistMan, fConfigAddJSONHistograms.value.c_str());                    // ad-hoc histograms via JSON
       VarManager::SetUseVars(fHistMan->GetUsedVars());                                                          // provide the list of required variables so that VarManager knows what to fill
       fOutputList.setObject(fHistMan->GetMainHistogramList());
@@ -1749,6 +1756,7 @@ struct AnalysisSameEventPairing {
     constexpr bool eventHasQvectorCentr = ((TEventFillMap & VarManager::ObjTypes::CollisionQvect) > 0);
     constexpr bool trackHasCov = ((TTrackFillMap & VarManager::ObjTypes::TrackCov) > 0 || (TTrackFillMap & VarManager::ObjTypes::ReducedTrackBarrelCov) > 0);
     bool isSelectedBDT = false;
+    fNPairPerEvent = 0;
 
     for (auto& event : events) {
       if (!event.isEventSelected_bit(0)) {
@@ -1796,6 +1804,7 @@ struct AnalysisSameEventPairing {
             twoTrackFilter |= (static_cast<uint32_t>(1) << 31);
           }
 
+          fNPairPerEvent++;
           VarManager::FillPair<TPairType, TTrackFillMap>(t1, t2);
           // compute quantities which depend on the associated collision, such as DCA
           if (fConfigOptions.propTrack) {
@@ -2101,6 +2110,10 @@ struct AnalysisSameEventPairing {
           }
         } // end loop (cuts)
       } // end loop over pairs of track associations
+      VarManager::fgValues[VarManager::kNPairsPerEvent] = fNPairPerEvent;
+      if (fEnableBarrelHistos && fConfigQA) {
+        fHistMan->FillHistClass("PairingSEQA", VarManager::fgValues);
+      }
     } // end loop over events
   }
 
@@ -2120,6 +2133,7 @@ struct AnalysisSameEventPairing {
           }
           auto t1 = a1.template reducedtrack_as<TTracks1>();
           auto t2 = a2.template reducedtrack_as<TTracks2>();
+          fNPairPerEvent++;
           VarManager::FillPairME<TEventFillMap, TPairType>(t1, t2);
           if constexpr ((TEventFillMap & VarManager::ObjTypes::ReducedEventQvector) > 0) {
             VarManager::FillPairVn<TEventFillMap, TPairType>(t1, t2);
@@ -2285,7 +2299,12 @@ struct AnalysisSameEventPairing {
       auto assocs2 = assocs.sliceBy(preSlice, event2.globalIndex());
       assocs2.bindExternalIndices(&events);
 
+      fNPairPerEvent = 0;
       runMixedPairing<TPairType, TEventFillMap>(assocs1, assocs2, tracks, tracks);
+      VarManager::fgValues[VarManager::kNPairsPerEvent] = fNPairPerEvent;
+      if (fEnableBarrelMixingHistos && fConfigQA) {
+        fHistMan->FillHistClass("PairingMEQA", VarManager::fgValues);
+      }
     } // end event loop
   }
 
@@ -4274,6 +4293,10 @@ void DefineHistograms(HistogramManager* histMan, TString histClasses, const char
       dqhistograms::DefineHistograms(histMan, objArray->At(iclass)->GetName(), "pair", histName);
     }
 
+    if (classStr.Contains("Pairing")) {
+      dqhistograms::DefineHistograms(histMan, objArray->At(iclass)->GetName(), "event", histName);
+    }
+
     if (classStr.Contains("Triplets")) {
       dqhistograms::DefineHistograms(histMan, objArray->At(iclass)->GetName(), "pair", histName);
     }