Configurable invariant mass axis

Author: jaelpark

PWGCF/Tasks/correlations.cxx

@@ -81,6 +81,7 @@ struct CorrelationTask {
   O2_DEFINE_CONFIGURABLE(cfgVerbosity, int, 1, "Verbosity level (0 = major, 1 = per collision)")
 
   O2_DEFINE_CONFIGURABLE(cfgDecayParticleMask, int, 0, "Selection bitmask for the decay particles: 0 = no selection")
+  O2_DEFINE_CONFIGURABLE(cfgMassAxis, int, 0, "Use invariant mass axis (0 = OFF, 1 = ON)")
 
   ConfigurableAxis axisVertex{"axisVertex", {7, -7, 7}, "vertex axis for histograms"};
   ConfigurableAxis axisDeltaPhi{"axisDeltaPhi", {72, -PIHalf, PIHalf * 3}, "delta phi axis for histograms"};
@@ -93,8 +94,7 @@ struct CorrelationTask {
   ConfigurableAxis axisEtaEfficiency{"axisEtaEfficiency", {20, -1.0, 1.0}, "eta axis for efficiency histograms"};
   ConfigurableAxis axisPtEfficiency{"axisPtEfficiency", {VARIABLE_WIDTH, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3.0, 3.25, 3.5, 3.75, 4.0, 4.5, 5.0, 6.0, 7.0, 8.0}, "pt axis for efficiency histograms"};
 
-  // Use one mass bin only by default in case mass dependency is not needed
-  ConfigurableAxis axisInvMass{"axisInvMass", {1, -1.0, 1.0}, "invariant mass axis for histograms"};
+  ConfigurableAxis axisInvMass{"axisInvMass", {VARIABLE_WIDTH, 0, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2.0, 5.0}, "invariant mass axis for histograms"};
   ConfigurableAxis axisInvMassHistogram{"axisInvMassHistogram", {1000, 1.0, 3.0}, "invariant mass histogram binning"};
 
   // This filter is applied to AOD and derived data (column names are identical)
@@ -177,7 +177,7 @@ struct CorrelationTask {
     std::vector<AxisSpec> effAxis = {{axisEtaEfficiency, "#eta"},
                                      {axisPtEfficiency, "p_{T} (GeV/c)"},
                                      {axisVertexEfficiency, "z-vtx (cm)"}};
-    std::vector<AxisSpec> userAxis = {{axisInvMass, "m (GeV/c^2)"}};
+    std::vector<AxisSpec> userAxis = cfgMassAxis != 0 ? {{axisInvMass, "m (GeV/c^2)"}} : {};
     same.setObject(new CorrelationContainer("sameEvent", "sameEvent", corrAxis, effAxis, userAxis));
     mixed.setObject(new CorrelationContainer("mixedEvent", "mixedEvent", corrAxis, effAxis, userAxis));
 
@@ -385,14 +385,15 @@ struct CorrelationTask {
           deltaPhi += TwoPI;
         }
 
-        float invMass;
-        if constexpr (std::experimental::is_detected<hasInvMass, typename TTracks1::iterator>::value)
-          invMass = track1.invMass();
-        else
-          invMass = 0.0f;
         // last param is the weight
-        target->getPairHist()->Fill(step,
-                                    track1.eta() - track2.eta(), track2.pt(), track1.pt(), multiplicity, deltaPhi, posZ, invMass, associatedWeight);
+        const double params[] = {track1.eta() - track2.eta(), track2.pt(), track1.pt(), multiplicity, deltaPhi, posZ, associatedWeight, associatedWeight};
+        if (cfgMassAxis) {
+          if constexpr (std::experimental::is_detected<hasInvMass, typename TTracks1::iterator>::value)
+            params[6] = track1.invMass();
+          else
+            params[6] = 0.0f;
+        }
+        target->getPairHist()->Fill(step, 7 + cfgMassAxis, params);
       }
     }
   }