[PWGDQ] Adding MC centrality to table-maker-mc-with-assoc (#13372)

Co-authored-by: Lucamicheletti93 <luca.mike93@gmail.com>

Author: lucamicheletti93

PWGDQ/Core/HistogramsLibrary.cxx

@@ -222,6 +222,7 @@ void o2::aod::dqhistograms::DefineHistograms(HistogramManager* hm, const char* h
       hm->AddHistogram(histClass, "MCVtxZ_VtxX", "Vtx X vs Vtx Z", false, 60, -15.0, 15.0, VarManager::kMCVtxZ, 200, -0.2, 0.2, VarManager::kMCVtxX);
       hm->AddHistogram(histClass, "MCVtxX_VtxY", "Vtx X vs Vtx Y", false, 200, 15.0, 15.0, VarManager::kMCVtxZ, 200, -0.2, 0.2, VarManager::kMCVtxY);
       hm->AddHistogram(histClass, "MCImpPar", "MC impact param", false, 20, 0.0, 20.0, VarManager::kMCEventImpParam);
+      hm->AddHistogram(histClass, "MCCentrFT0C", "MC Centrality FT0C", false, 100, 0.0, 100.0, VarManager::kMCEventCentrFT0C);
     }
     if (subGroupStr.Contains("subgen")) {
       hm->AddHistogram(histClass, "SubGenID", "SubGenerator ID", false, 11, -0.5, 10.5, VarManager::kMCEventSubGeneratorId);
@@ -950,13 +951,13 @@ void o2::aod::dqhistograms::DefineHistograms(HistogramManager* hm, const char* h
     hm->AddHistogram(histClass, "EtaMC", "MC #eta", false, 50, -5.0, 5.0, VarManager::kMCEta);
     hm->AddHistogram(histClass, "PhiMC", "MC #phi", false, 50, -6.3, 6.3, VarManager::kMCPhi);
     hm->AddHistogram(histClass, "YMC", "MC y", false, 50, -5.0, 5.0, VarManager::kMCY);
-    hm->AddHistogram(histClass, "CentFT0CMC", "MC Cent. FT0C", false, 18, 0., 90., VarManager::kCentFT0C);
+    hm->AddHistogram(histClass, "CentFT0CMC", "MC Cent. FT0C", false, 18, 0., 90., VarManager::kMCEventCentrFT0C);
     hm->AddHistogram(histClass, "PtMC_YMC", "MC pT vs MC y", false, 120, 0.0, 30.0, VarManager::kMCPt, 1000, -5.0, 5.0, VarManager::kMCY);
     hm->AddHistogram(histClass, "EtaMC_PtMC", "", false, 40, -2.0, 2.0, VarManager::kMCEta, 200, 0.0, 20.0, VarManager::kMCPt);
     hm->AddHistogram(histClass, "VzMC", "MC vz", false, 100, -15.0, 15.0, VarManager::kMCVz);
     hm->AddHistogram(histClass, "VzMC_VtxZMC", "MC vz vs MC vtxZ", false, 50, -15.0, 15.0, VarManager::kMCVz, 50, -15.0, 15.0, VarManager::kMCVtxZ);
     hm->AddHistogram(histClass, "Weight", "", false, 50, 0.0, 5.0, VarManager::kMCParticleWeight);
-    hm->AddHistogram(histClass, "MCImpPar_CentFT0CMC", "MC impact param vs MC Cent. FT0C", false, 20, 0.0, 20.0, VarManager::kMCEventImpParam, 100, 0.0, 100.0, VarManager::kCentFT0C);
+    hm->AddHistogram(histClass, "MCImpPar_CentFT0CMC", "MC impact param vs MC Cent. FT0C", false, 20, 0.0, 20.0, VarManager::kMCEventImpParam, 100, 0.0, 100.0, VarManager::kMCEventCentrFT0C);
   }
 
   if (!groupStr.CompareTo("pair")) {

PWGDQ/Core/VarManager.cxx

@@ -445,6 +445,7 @@ void VarManager::SetDefaultVarNames()
   fgVariableNames[kMCEventTime] = "MC event time";
   fgVariableNames[kMCEventWeight] = "MC event weight";
   fgVariableNames[kMCEventImpParam] = "MC impact parameter";
+  fgVariableNames[kMCEventCentrFT0C] = "MC Centrality FT0C";
   fgVariableUnits[kMCEventGeneratorId] = "";
   fgVariableUnits[kMCEventSubGeneratorId] = "";
   fgVariableUnits[kMCVtxX] = "cm";
@@ -453,6 +454,7 @@ void VarManager::SetDefaultVarNames()
   fgVariableUnits[kMCEventTime] = ""; // TODO: add proper unit
   fgVariableUnits[kMCEventWeight] = "";
   fgVariableUnits[kMCEventImpParam] = "b";
+  fgVariableUnits[kMCEventCentrFT0C] = "%";
   fgVariableNames[kTwoEvPosZ1] = "vtx-z_{1}";
   fgVariableUnits[kTwoEvPosZ1] = "cm";
   fgVariableNames[kTwoEvPosZ2] = "vtx-z_{2}";

PWGDQ/Core/VarManager.h

@@ -282,6 +282,7 @@ class VarManager : public TObject
     kMCEventTime,
     kMCEventWeight,
     kMCEventImpParam,
+    kMCEventCentrFT0C,
     kQ1ZNAX,
     kQ1ZNAY,
     kQ1ZNCX,
@@ -1655,9 +1656,11 @@ void VarManager::FillEvent(T const& event, float* values)
   }
 
   if constexpr ((fillMap & CollisionCent) > 0 || (fillMap & ReducedEventExtended) > 0) {
-    values[kCentFT0C] = event.centFT0C();
-    values[kCentFT0A] = event.centFT0A();
-    values[kCentFT0M] = event.centFT0M();
+    if constexpr ((fillMap & CollisionMC) == 0) {
+      values[kCentFT0C] = event.centFT0C();
+      values[kCentFT0A] = event.centFT0A();
+      values[kCentFT0M] = event.centFT0M();
+    }
   }
 
   if constexpr ((fillMap & CollisionMult) > 0 || (fillMap & ReducedEventExtended) > 0) {
@@ -1982,6 +1985,10 @@ void VarManager::FillEvent(T const& event, float* values)
     values[kMCEventTime] = event.t();
     values[kMCEventWeight] = event.weight();
     values[kMCEventImpParam] = event.impactParameter();
+    if constexpr ((fillMap & CollisionCent) > 0) {
+      // WARNING: temporary solution, ongoing work to provide proper MC gen. centrality
+      values[kMCEventCentrFT0C] = event.bestCollisionCentFT0C();
+    }
   }
 
   if constexpr ((fillMap & ReducedEventMC) > 0) {