[PWGHF] Add alternative FT0c centrality estimator in HF centrality (#15261)

Co-authored-by: ALICE Action Bot <alibuild@cern.ch>

Author: stefanopolitano

PWGHF/Core/CentralityEstimation.h

@@ -30,6 +30,7 @@ enum CentralityEstimator {
   FT0M,
   FV0A,
   NTracksPV,
+  FT0CVariant2,
   NCentralityEstimators
 };
 
@@ -43,6 +44,11 @@ concept HasFT0CCent = requires(T collision) {
   collision.centFT0C();
 };
 
+template <typename T>
+concept HasFT0CVariant2Cent = requires(T collision) {
+  collision.centFT0CVariant2();
+};
+
 template <typename T>
 concept HasFT0MCent = requires(T collision) {
   collision.centFT0M();
@@ -76,6 +82,15 @@ float getCentralityColl(const TCollision& collision)
   return collision.centFT0C();
 }
 
+/// Evaluate centrality/multiplicity percentile using FT0C variant 1 estimator
+/// \param candidate is candidate
+/// \return centrality/multiplicity percentile of the collision
+template <HasFT0CVariant2Cent TCollision>
+float getCentralityColl(const TCollision& collision)
+{
+  return collision.centFT0CVariant2();
+}
+
 /// Evaluate centrality/multiplicity percentile using FT0M estimator
 /// \param candidate is candidate
 /// \return centrality/multiplicity percentile of the collision
@@ -144,6 +159,18 @@ float getCentralityColl(const TCollision& collision, const int centEstimator)
       }
       LOG(fatal) << "Collision does not have centFV0A().";
       break;
+    case CentralityEstimator::NTracksPV:
+      if constexpr (HasNTracksPvCent<TCollision>) {
+        return collision.centNTPV();
+      }
+      LOG(fatal) << "Collision does not have centNTPV().";
+      break;
+    case CentralityEstimator::FT0CVariant2:
+      if constexpr (HasFT0CVariant2Cent<TCollision>) {
+        return collision.centFT0CVariant2();
+      }
+      LOG(fatal) << "Collision does not have centFT0CVariant2().";
+      break;
     default:
       LOG(fatal) << "Centrality estimator not valid. See CentralityEstimator for valid values.";
       break;

PWGHF/D2H/Tasks/taskFlowCharmHadrons.cxx

@@ -109,7 +109,7 @@ struct HfTaskFlowCharmHadrons {
 
   Configurable<int> harmonic{"harmonic", 2, "harmonic number"};
   Configurable<int> qVecDetector{"qVecDetector", 3, "Detector for Q vector estimation (FV0A: 0, FT0M: 1, FT0A: 2, FT0C: 3, TPC Pos: 4, TPC Neg: 5, TPC Tot: 6)"};
-  Configurable<int> centEstimator{"centEstimator", 2, "Centrality estimation (FT0A: 1, FT0C: 2, FT0M: 3, FV0A: 4)"};
+  Configurable<int> centEstimator{"centEstimator", 2, "Centrality estimation (FT0A: 1, FT0C: 2, FT0M: 3, FV0A: 4, NTracksPV: 5, FT0CVariant2: 6)"};
   Configurable<int> selectionFlag{"selectionFlag", 1, "Selection Flag for hadron (e.g. 1 for skimming, 3 for topo. and kine., 7 for PID)"};
   Configurable<float> centralityMin{"centralityMin", 0., "Minimum centrality accepted in SP/EP computation (not applied in resolution process)"};
   Configurable<float> centralityMax{"centralityMax", 100., "Maximum centrality accepted in SP/EP computation (not applied in resolution process)"};
@@ -124,6 +124,8 @@ struct HfTaskFlowCharmHadrons {
   Configurable<bool> storeEpCosSin{"storeEpCosSin", false, "Flag to store cos and sin of EP angle in ThnSparse"};
   Configurable<bool> storeCandEta{"storeCandEta", false, "Flag to store candidates eta"};
   Configurable<bool> storeCandSign{"storeCandSign", false, "Flag to store candidates sign"};
+  Configurable<bool> storeCentSparse{"storeCentSparse", false, "Flag to store up to 4 centrality estimators comparison sparse (only applied in resolution process)"};
+  Configurable<std::vector<int>> centEstimatorsForSparse{"centEstimatorsForSparse", {1, 2, 3, 4}, "Centrality estimators to be stored in the centrality sparse (FT0A: 1, FT0C: 2, FT0M: 3, FV0A: 4). Up to 4 estimators can be configured."};
   Configurable<int> occEstimator{"occEstimator", 0, "Occupancy estimation (0: None, 1: ITS, 2: FT0C)"};
   Configurable<bool> saveEpResoHisto{"saveEpResoHisto", false, "Flag to save event plane resolution histogram"};
   Configurable<std::string> ccdbUrl{"ccdbUrl", "http://alice-ccdb.cern.ch", "url of the ccdb repository"};
@@ -146,7 +148,7 @@ struct HfTaskFlowCharmHadrons {
   using CandXic0DataWMl = soa::Filtered<soa::Join<aod::HfCandToXiPiKf, aod::HfSelToXiPiKf, aod::HfMlToXiPi>>;
   using CandD0DataWMl = soa::Filtered<soa::Join<aod::HfCand2Prong, aod::HfSelD0, aod::HfMlD0>>;
   using CandD0Data = soa::Filtered<soa::Join<aod::HfCand2Prong, aod::HfSelD0>>;
-  using CollsWithQvecs = soa::Join<aod::Collisions, aod::EvSels, aod::QvectorFT0Cs, aod::QvectorFT0As, aod::QvectorFT0Ms, aod::QvectorFV0As, aod::QvectorBPoss, aod::QvectorBNegs, aod::QvectorBTots, aod::CentFV0As, aod::CentFT0Ms, aod::CentFT0As, aod::CentFT0Cs>;
+  using CollsWithQvecs = soa::Join<aod::Collisions, aod::EvSels, aod::QvectorFT0Cs, aod::QvectorFT0As, aod::QvectorFT0Ms, aod::QvectorFV0As, aod::QvectorBPoss, aod::QvectorBNegs, aod::QvectorBTots, aod::CentFV0As, aod::CentFT0Ms, aod::CentFT0As, aod::CentFT0Cs, aod::CentFT0CVariant2s>;
   using TracksWithExtra = soa::Join<aod::Tracks, aod::TracksExtra>;
 
   Filter filterSelectDsCandidates = aod::hf_sel_candidate_ds::isSelDsToKKPi >= selectionFlag || aod::hf_sel_candidate_ds::isSelDsToPiKK >= selectionFlag;
@@ -254,6 +256,11 @@ struct HfTaskFlowCharmHadrons {
     registry.add("hCentEventWithCand", "Centrality distributions with charm candidates;Cent;entries", HistType::kTH1F, {{100, 0.f, 100.f}});
     registry.add("hCentEventWithCandInSigRegion", "Centrality distributions with charm candidates in signal range;Cent;entries", HistType::kTH1F, {{100, 0.f, 100.f}});
 
+    if (storeCentSparse) {
+      std::vector<AxisSpec> axesCent = {thnAxisCent, thnAxisCent, thnAxisCent, thnAxisCent};
+      registry.add("hSparseCentEstimators", "THn with different centrality estimators; Centrality 0; Centrality 1; Centrality 2; Centrality 3", {HistType::kTHnSparseF, axesCent});
+    }
+
     if (occEstimator != 0) {
       registry.add("trackOccVsFT0COcc", "trackOccVsFT0COcc; trackOcc; FT0COcc", {HistType::kTH2F, {thnAxisOccupancyITS, thnAxisOccupancyFT0C}});
     }
@@ -878,7 +885,7 @@ struct HfTaskFlowCharmHadrons {
     float const xQVecBTot = collision.qvecBTotRe();
     float const yQVecBTot = collision.qvecBTotIm();
 
-    centrality = o2::hf_centrality::getCentralityColl(collision, o2::hf_centrality::CentralityEstimator::FT0C);
+    centrality = o2::hf_centrality::getCentralityColl(collision, centEstimator);
     if (storeResoOccu) {
       const auto occupancy = o2::hf_occupancy::getOccupancyColl(collision, occEstimator);
       registry.fill(HIST("trackOccVsFT0COcc"), collision.trackOccupancyInTimeRange(), collision.ft0cOccupancyInTimeRange());
@@ -890,6 +897,11 @@ struct HfTaskFlowCharmHadrons {
                     occupancy, evtSelFlags[0], evtSelFlags[1], evtSelFlags[2], evtSelFlags[3], evtSelFlags[4]);
     }
 
+    if (storeCentSparse) {
+      registry.fill(HIST("hSparseCentEstimators"), o2::hf_centrality::getCentralityColl(collision, centEstimatorsForSparse->at(0)), o2::hf_centrality::getCentralityColl(collision, centEstimatorsForSparse->at(1)),
+                    o2::hf_centrality::getCentralityColl(collision, centEstimatorsForSparse->at(2)), o2::hf_centrality::getCentralityColl(collision, centEstimatorsForSparse->at(3)));
+    }
+
     if (!isCollSelected<o2::hf_centrality::CentralityEstimator::FT0C>(collision, bcs, centrality)) {
       // no selection on the centrality is applied, but on event selection flags
       return;