From c1fda16f27b93519f24cc0f07aea436eb463f7e1 Mon Sep 17 00:00:00 2001
From: Marvin Hemmer <marvin.hemmer@cern.ch>
Date: Fri, 16 May 2025 10:04:51 +0200
Subject: [PATCH] [EMCAL-688] EMCAL: Add fCross to the AnalysisCluster

- Add fCross the exoticity parameter to the AnalysisCluster so we can easily access it later in the emcalCorrectionTask in O2Physics
---
 .../EMCAL/include/DataFormatsEMCAL/AnalysisCluster.h |  8 ++++++--
 .../EMCAL/base/include/EMCALBase/ClusterFactory.h    |  5 +++--
 Detectors/EMCAL/base/src/ClusterFactory.cxx          | 12 ++++++++----
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/DataFormats/Detectors/EMCAL/include/DataFormatsEMCAL/AnalysisCluster.h b/DataFormats/Detectors/EMCAL/include/DataFormatsEMCAL/AnalysisCluster.h
index 758e0a1fa0b47..e19fd17dea2ce 100644
--- a/DataFormats/Detectors/EMCAL/include/DataFormatsEMCAL/AnalysisCluster.h
+++ b/DataFormats/Detectors/EMCAL/include/DataFormatsEMCAL/AnalysisCluster.h
@@ -182,6 +182,9 @@ class AnalysisCluster
   float getCoreEnergy() const { return mCoreEnergy; }
   void setCoreEnergy(float energy) { mCoreEnergy = energy; }
 
+  float getFCross() const { return mFCross; }
+  void setFCross(float fCross) { mFCross = fCross; }
+
   ///
   /// Returns TLorentzVector with momentum of the cluster. Only valid for clusters
   /// identified as photons or pi0 (overlapped gamma) produced on the vertex
@@ -223,12 +226,13 @@ class AnalysisCluster
   float mTime = 0.; ///<  Time of the digit/cell with maximal energy deposition
 
   bool mIsExotic = false; //!<! Cluster marked as "exotic" (high energy deposition concentrated in a single cell)
+  float mFCross = 0.f;    //! exoticity parameter (1-E_cross/E_cell^max)
 
   int mInputIndMax = -1; ///<  index of digit/cell with max energy
 
-  ClassDefNV(AnalysisCluster, 1);
+  ClassDefNV(AnalysisCluster, 2);
 };
 
 } // namespace emcal
 } // namespace o2
-#endif //ANALYSISCLUSTER_H
+#endif // ANALYSISCLUSTER_H
diff --git a/Detectors/EMCAL/base/include/EMCALBase/ClusterFactory.h b/Detectors/EMCAL/base/include/EMCALBase/ClusterFactory.h
index 2957eacb8d050..3ce7003fe9814 100644
--- a/Detectors/EMCAL/base/include/EMCALBase/ClusterFactory.h
+++ b/Detectors/EMCAL/base/include/EMCALBase/ClusterFactory.h
@@ -277,9 +277,10 @@ class ClusterFactory
   /// \brief Look to cell neighbourhood and reject if it seems exotic
   /// \param towerId: tower ID of cell with largest energy fraction in cluster
   /// \param ecell: energy of the cell with largest energy fraction in cluster
-  /// \param exoticTime time of the cell with largest energy fraction in cluster
+  /// \param exoticTime: time of the cell with largest energy fraction in cluster
+  /// \param fCross: exoticity parameter (1-E_cross/E_cell^max) will be caluclated for this check
   /// \return bool true if cell is found exotic
-  bool isExoticCell(short towerId, float ecell, float const exoticTime) const;
+  bool isExoticCell(short towerId, float ecell, float const exoticTime, float& fCross) const;
 
   /// \brief Calculate the energy in the cross around the energy of a given cell.
   /// \param absID: controlled cell absolute ID number
diff --git a/Detectors/EMCAL/base/src/ClusterFactory.cxx b/Detectors/EMCAL/base/src/ClusterFactory.cxx
index 0c801de615487..342f54fd94591 100644
--- a/Detectors/EMCAL/base/src/ClusterFactory.cxx
+++ b/Detectors/EMCAL/base/src/ClusterFactory.cxx
@@ -73,8 +73,11 @@ o2::emcal::AnalysisCluster ClusterFactory<InputType>::buildCluster(int clusterIn
 
   float exoticTime = mInputsContainer[inputIndMax].getTimeStamp();
 
+  float fCross = 0.;
+
   try {
-    clusterAnalysis.setIsExotic(isExoticCell(towerId, inputEnergyMax, exoticTime));
+    clusterAnalysis.setIsExotic(isExoticCell(towerId, inputEnergyMax, exoticTime, fCross));
+    clusterAnalysis.setFCross(fCross);
   } catch (UninitLookUpTableException& e) {
     LOG(error) << e.what();
   }
@@ -253,7 +256,7 @@ void ClusterFactory<InputType>::evalLocalPosition(gsl::span<const int> inputsInd
         clRmsXYZ[i] += (w * xyzi[i] * xyzi[i]);
       }
     } // w > 0
-  }   // dig loop
+  } // dig loop
 
   //  cout << " wtot " << wtot << endl;
 
@@ -600,7 +603,7 @@ std::tuple<int, float, float, bool> ClusterFactory<InputType>::getMaximalEnergyI
 /// Look to cell neighbourhood and reject if it seems exotic
 //____________________________________________________________________________
 template <class InputType>
-bool ClusterFactory<InputType>::isExoticCell(short towerId, float ecell, float const exoticTime) const
+bool ClusterFactory<InputType>::isExoticCell(short towerId, float ecell, float const exoticTime, float& fCross) const
 {
   if (ecell < mExoticCellMinAmplitude) {
     return false; // do not reject low energy cells
@@ -612,8 +615,9 @@ bool ClusterFactory<InputType>::isExoticCell(short towerId, float ecell, float c
   }
 
   float eCross = getECross(towerId, ecell, exoticTime);
+  fCross = 1.f - eCross / ecell;
 
-  if (1 - eCross / ecell > mExoticCellFraction) {
+  if (fCross > mExoticCellFraction) {
     LOG(debug) << "EXOTIC CELL id " << towerId << ", eCell " << ecell << ", eCross " << eCross << ", 1-eCross/eCell " << 1 - eCross / ecell;
     return true;
   }