[PWGLF] move ME definition & add dedicated ME autocorrelation QA in cascade correlations (#8905)

Co-authored-by: ALICE Builder <alibuild@users.noreply.github.com>

Author: rspijkers

PWGLF/Tasks/Strangeness/cascadecorrelations.cxx

@@ -426,6 +426,8 @@ struct CascadeCorrelations {
       {"MixedEvents/hMEDeltaPhiSS", "hMEDeltaPhiSS", {HistType::kTH1F, {deltaPhiAxis}}},
       {"MixedEvents/hMEDeltaPhiOS", "hMEDeltaPhiOS", {HistType::kTH1F, {deltaPhiAxis}}},
       {"MixedEvents/hMEQA", "hMEQA", {HistType::kTH1I, {{2, 0, 2, "QA for exceptions in ME (this histogram should have 0 entries!)"}}}},
+      {"MixedEvents/hMEAutoCorrelation", "hMEAutoCorrelation", {HistType::kTH1I, {{4, -0.5f, 3.5f, "Types of SS autocorrelation"}}}},
+      {"MixedEvents/hMEAutoCorrelationOS", "hMEAutoCorrelationOS", {HistType::kTH1I, {{2, -1.f, 1.f, "Charge of OS autocorrelated track"}}}},
 
       {"MixedEvents/hMEXiXiOS", "hMEXiXiOS", {HistType::kTHnSparseF, {deltaPhiAxis, deltaYAxis, ptAxis, ptAxis, invMassAxis, invMassAxis, vertexAxis, multiplicityAxis}}, true},
       {"MixedEvents/hMEXiXiSS", "hMEXiXiSS", {HistType::kTHnSparseF, {deltaPhiAxis, deltaYAxis, ptAxis, ptAxis, invMassAxis, invMassAxis, vertexAxis, multiplicityAxis}}, true},
@@ -441,9 +443,15 @@ struct CascadeCorrelations {
   // cascade filter
   Filter cascadeSelector = aod::cascadeflags::isSelected > 0;
 
+  // Warning: it is not possible to use this axis as configurable due to a bug - however, default values are sensible.
   SliceCache cache;
   ConfigurableAxis axisVtxZ{"axisVtxZ", {VARIABLE_WIDTH, -10.0f, -8.f, -6.f, -4.f, -2.f, 0.f, 2.f, 4.f, 6.f, 8.f, 10.f}, "Mixing bins - z-vertex"};
   // ConfigurableAxis axisMult{"axisMult", {VARIABLE_WIDTH, 0, 5, 10, 20, 30, 40, 50, 100, 1000}, "Mixing bins - multiplicity"};
+  // using BinningType = ColumnBinningPolicy<aod::collision::PosZ, aod::mult::MultFT0M<aod::mult::MultFT0A, aod::mult::MultFT0C>>;
+  // BinningType colBinning{{axisVtxZ, axisMult}, true}; // true is for 'ignore overflows' (true by default). Underflows and overflows will have bin -1.
+  using BinningType = ColumnBinningPolicy<aod::collision::PosZ>;
+  BinningType colBinning{{axisVtxZ}, true}; // true is for 'ignore overflows' (true by default). Underflows and overflows will have bin -1.
+  SameKindPair<MyCollisionsMult, MyCascades, BinningType> pair{colBinning, nMixedEvents, -1, &cache};
 
   void processSameEvent(MyCollisionsMult::iterator const& collision, MyCascades const& Cascades, aod::V0sLinked const&, aod::V0Datas const&, FullTracksExtIU const&, aod::BCsWithTimestamps const&)
   {
@@ -662,13 +670,6 @@ struct CascadeCorrelations {
   void processMixedEvent(MyCollisionsMult const& /*collisions*/, MyCascades const& /*Cascades*/,
                          aod::V0sLinked const&, aod::V0Datas const&, FullTracksExtIU const&)
   {
-    // mixed events
-    // using BinningType = ColumnBinningPolicy<aod::collision::PosZ, aod::mult::MultFT0M<aod::mult::MultFT0A, aod::mult::MultFT0C>>;
-    // BinningType colBinning{{axisVtxZ, axisMult}, true}; // true is for 'ignore overflows' (true by default). Underflows and overflows will have bin -1.
-    using BinningType = ColumnBinningPolicy<aod::collision::PosZ>;
-    BinningType colBinning{{axisVtxZ}, true}; // true is for 'ignore overflows' (true by default). Underflows and overflows will have bin -1.
-    SameKindPair<MyCollisionsMult, MyCascades, BinningType> pair{colBinning, nMixedEvents, -1, &cache};
-
     for (auto const& [col1, cascades1, col2, cascades2] : pair) {
       if (!col1.sel8() || !col2.sel8())
         continue;
@@ -719,24 +720,24 @@ struct CascadeCorrelations {
           if (trigger.isSelected() >= 2) {
             if (trigger.sign() > 0 && trigger.bachelorId() == posIdAssoc) {
               // K+ from trigger Omega is the same as proton from assoc lambda
-              registry.fill(HIST("hAutoCorrelationOS"), 1);
+              registry.fill(HIST("hMEAutoCorrelationOS"), 1);
               continue;
             }
             if (trigger.sign() < 0 && trigger.bachelorId() == negIdAssoc) {
               // K- from trigger Omega is the same as antiproton from assoc antilambda
-              registry.fill(HIST("hAutoCorrelationOS"), -1);
+              registry.fill(HIST("hMEAutoCorrelationOS"), -1);
               continue;
             }
           }
           if (assoc.isSelected() >= 2) {
             if (assoc.sign() > 0 && assoc.bachelorId() == posIdTrigg) {
               // K+ from assoc Omega is the same as proton from trigger lambda
-              registry.fill(HIST("hAutoCorrelationOS"), 1);
+              registry.fill(HIST("hMEAutoCorrelationOS"), 1);
               continue;
             }
             if (assoc.sign() < 0 && assoc.bachelorId() == negIdTrigg) {
               // K- from assoc Omega is the same as antiproton from trigger antilambda
-              registry.fill(HIST("hAutoCorrelationOS"), -1);
+              registry.fill(HIST("hMEAutoCorrelationOS"), -1);
               continue;
             }
           }
@@ -776,33 +777,33 @@ struct CascadeCorrelations {
           // make sure to check for autocorrelations - only possible in same-sign correlations (if PID is correct)
           if (posIdTrigg == posIdAssoc && negIdTrigg == negIdAssoc) {
             // LOGF(info, "same v0 in SS correlation! %d %d", v0dataTrigg.v0Id(), v0dataAssoc.v0Id());
-            registry.fill(HIST("hAutoCorrelation"), 0);
+            registry.fill(HIST("hMEAutoCorrelation"), 0);
             continue;
           }
           int bachIdTrigg = trigger.bachelorId();
           int bachIdAssoc = assoc.bachelorId();
 
           if (bachIdTrigg == bachIdAssoc) {
             // LOGF(info, "same bachelor in SS correlation! %d %d", bachIdTrigg, bachIdAssoc);
-            registry.fill(HIST("hAutoCorrelation"), 1);
+            registry.fill(HIST("hMEAutoCorrelation"), 1);
             continue;
           }
           // check for same tracks in v0's of cascades
           if (negIdTrigg == negIdAssoc || posIdTrigg == posIdAssoc) {
             // LOGF(info, "cascades have a v0-track in common in SS correlation!");
-            registry.fill(HIST("hAutoCorrelation"), 2);
+            registry.fill(HIST("hMEAutoCorrelation"), 2);
             continue;
           }
           if (trigger.sign() < 0) { // neg cascade
             if (negIdTrigg == bachIdAssoc || negIdAssoc == bachIdTrigg) {
               // LOGF(info, "bach of casc == v0-pion of other casc in neg SS correlation!");
-              registry.fill(HIST("hAutoCorrelation"), 3);
+              registry.fill(HIST("hMEAutoCorrelation"), 3);
               continue;
             }
           } else { // pos cascade
             if (posIdTrigg == bachIdAssoc || posIdAssoc == bachIdTrigg) {
               // LOGF(info, "bach of casc == v0-pion of other casc in pos SS correlation!");
-              registry.fill(HIST("hAutoCorrelation"), 3);
+              registry.fill(HIST("hMEAutoCorrelation"), 3);
               continue;
             }
           }
@@ -840,7 +841,7 @@ struct CascadeCorrelations {
         } // same sign
       } // correlations
     } // collisions
-  }     // process mixed events
+  } // process mixed events
 
   PROCESS_SWITCH(CascadeCorrelations, processSameEvent, "Process same events", true);
   PROCESS_SWITCH(CascadeCorrelations, processMixedEvent, "Process mixed events", true);