[PWGCF] jEPFlowAnalysis.cxx: add angular selection for two leading tracks (#17291)

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

Author: jikim1290

PWGCF/JCorran/Tasks/jEPFlowAnalysis.cxx

@@ -154,6 +154,8 @@ struct JEPFlowAnalysis {
 
   Configurable<bool> cfgSelEvtTwoHP{"cfgSelEvtTwoHP", false, "event selection with two high pT"};
   Configurable<float> cfgHighPtSel{"cfgHighPtSel", 5.0, "pT threshold with cfgSelEvtTwoHP"};
+  Configurable<float> cfgTwoLPAngle{"cfgTwoLPAngle", 0.5, "azimuthal difference between two LP"};
+  Configurable<float> cfgEtaBalancing{"cfgEtaBalancing", 0.5, "pseudorapidity difference between two LP"};
 
   Configurable<std::string> cfgDetName{"cfgDetName", "FT0C", "The name of detector to be analyzed"};
   Configurable<std::string> cfgRefAName{"cfgRefAName", "TPCPos", "The name of detector for reference A"};
@@ -193,8 +195,14 @@ struct JEPFlowAnalysis {
 
   float activity = -1.;
   float qOvecM = -1.;
-  float highestPt = -1.;
-  float hPtPhi = -999.;
+
+  float leadingPt = -1.;
+  float leadingPhi = -999.;
+  float leadingEta = -999.;
+
+  float subleadingPt = -1.;
+  float subleadingPhi = -999.;
+  float subleadingEta = -999.;
 
   std::vector<TProfile3D*> shiftprofile{};
   std::string fullCCDBShiftCorrPath;
@@ -424,11 +432,33 @@ struct JEPFlowAnalysis {
       }
 
       if (cfgSelEvtTwoHP && i == 0) {
+        leadingPt = 0.0;
+        leadingPhi = 0.0;
+        leadingEta = 0.0;
+
+        subleadingPt = 0.0;
+        subleadingPhi = 0.0;
+        subleadingEta = 0.0;
+
         nHighPt = 0;
         for (const auto& track : tracks) {
           if (cfgTrkSelFlag && trackSel(track))
             continue;
 
+          if (leadingPt < track.pt()) {
+            subleadingPt = leadingPt;
+            subleadingPhi = leadingPhi;
+            subleadingEta = leadingEta;
+
+            leadingPt = track.pt();
+            leadingPhi = track.phi();
+            leadingEta = track.eta();
+          } else if (track.pt() > subleadingPt) {
+            subleadingPt = track.pt();
+            subleadingPhi = track.phi();
+            subleadingEta = track.eta();
+          }
+
           if (track.pt() > cfgHighPtSel)
             nHighPt++;
         }
@@ -437,6 +467,12 @@ struct JEPFlowAnalysis {
       if (cfgSelEvtTwoHP && nHighPt < minnHighPt)
         continue;
 
+      if (std::abs(RecoDecay::constrainAngle(leadingPhi - subleadingPhi, 0) - constants::math::PI) > cfgTwoLPAngle)
+        continue;
+
+      if (std::abs(leadingEta + subleadingEta) > cfgEtaBalancing)
+        continue;
+
       epFlowHistograms.fill(HIST("EpDet"), i + 2, cent, eps[0]);
       epFlowHistograms.fill(HIST("EpRefA"), i + 2, cent, eps[1]);
       epFlowHistograms.fill(HIST("EpRefB"), i + 2, cent, eps[2]);
@@ -486,17 +522,13 @@ struct JEPFlowAnalysis {
         continue;
       }
 
-      highestPt = 0.0;
-      hPtPhi = 0.0;
+      leadingPt = 0.0;
+      leadingPhi = 0.0;
+      leadingEta = 0.0;
       for (const auto& track : tracks) {
         if (cfgTrkSelFlag && trackSel(track))
           continue;
 
-        if (highestPt < track.pt()) {
-          highestPt = track.pt();
-          hPtPhi = track.phi();
-        }
-
         if (cfgEffCor) {
           weight = getEfficiencyCorrection(effMap, track.eta(), track.pt(), cent, coll.posZ());
         }
@@ -525,14 +557,14 @@ struct JEPFlowAnalysis {
         }
       }
       if (i == 0) { // second harmonic only
-        epFlowHistograms.fill(HIST("hQoverM"), cent, highestPt, qOvecM);
-        epFlowHistograms.fill(HIST("hActivity"), cent, highestPt, activity);
+        epFlowHistograms.fill(HIST("hQoverM"), cent, leadingPt, qOvecM);
+        epFlowHistograms.fill(HIST("hActivity"), cent, leadingPt, activity);
 
         epFlowHistograms.fill(HIST("hQoverM2M"), cent, coll.qvecAmp()[detId], qOvecM);
         epFlowHistograms.fill(HIST("hQoverM2Q2"), cent, q2Mag, qOvecM);
 
-        epFlowHistograms.fill(HIST("hQoverMdphi"), cent, RecoDecay::constrainAngle(hPtPhi - eps[0], -constants::math::PI), qOvecM);
-        epFlowHistograms.fill(HIST("hActivitydphi"), cent, RecoDecay::constrainAngle(hPtPhi - eps[0], -constants::math::PI), highestPt, activity);
+        epFlowHistograms.fill(HIST("hQoverMdphi"), cent, RecoDecay::constrainAngle(leadingPhi - eps[0], -constants::math::PI), qOvecM);
+        epFlowHistograms.fill(HIST("hActivitydphi"), cent, RecoDecay::constrainAngle(leadingPhi - eps[0], -constants::math::PI), leadingPt, activity);
       }
     }
   }