[PWGEM] PhotonMeson: Add new task to monitor photon resolution (#14877)

Author: mhemmer-cern

PWGEM/PhotonMeson/Core/V0PhotonCut.h

@@ -896,6 +896,30 @@ class V0PhotonCut : public TNamed
     mEmMlResponse->init();
   }
 
+  template <o2::soa::is_iterator TMCPhoton>
+  bool IsConversionPointInAcceptance(TMCPhoton const& mcphoton) const
+  {
+
+    float rGenXY = std::sqrt(std::pow(mcphoton.vx(), 2) + std::pow(mcphoton.vy(), 2));
+
+    // eta cut
+    if (mcphoton.eta() >= mMinV0Eta && mcphoton.eta() <= mMaxV0Eta) {
+      return false;
+    }
+
+    // radius cut
+    if (rGenXY < mMinRxy || mMaxRxy < rGenXY) {
+      return false;
+    }
+
+    // line cut
+    if (rGenXY < std::abs(mcphoton.vz()) * std::tan(2 * std::atan(std::exp(-mMaxV0Eta))) - mMaxMarginZ) {
+      return false;
+    }
+
+    return true;
+  }
+
   // Setters
   void SetV0PtRange(float minPt = 0.f, float maxPt = 1e10f);
   void SetV0EtaRange(float minEta = -1e10f, float maxEta = 1e10f);

PWGEM/PhotonMeson/TableProducer/associateMCinfoPhoton.cxx

@@ -356,6 +356,7 @@ struct AssociateMCInfoPhoton {
         }
         auto mcCollisionFromEMC = collisionFromEMC.mcCollision();
 
+        // TODO: check that this does not cause issues, since we have sometimes clusters that are only noise!
         auto mcphoton = mcParticles.iteratorAt(emccluster.emmcparticleIds()[0]);
 
         // if the MC truth particle corresponding to this reconstructed track which is not already written, add it to the skimmed MC stack

PWGEM/PhotonMeson/Tasks/CMakeLists.txt

@@ -196,3 +196,8 @@ o2physics_add_dpl_workflow(test-task-emc
                     SOURCES testTaskEmc.cxx
                     PUBLIC_LINK_LIBRARIES O2::Framework O2Physics::AnalysisCore O2::EMCALBase O2::EMCALCalib O2Physics::PWGEMPhotonMesonCore
                     COMPONENT_NAME Analysis)
+
+o2physics_add_dpl_workflow(photon-reso-task
+                    SOURCES photonResoTask.cxx
+                    PUBLIC_LINK_LIBRARIES O2::Framework O2Physics::AnalysisCore O2::EMCALBase O2::EMCALCalib O2Physics::PWGEMPhotonMesonCore
+                    COMPONENT_NAME Analysis)