[PWGJE] EMCal: Add cluster definition for low energy clusters for sigma0 analysis

- Add new clusterizer setting `kV3MostSplitSmallestTimeDiffLowestSeed` which has the lowest seed threshold of 100 MeV and a tight timing difference of 50 ns. This is experimental for a potential sigma0 analysis.

Author: mhemmer-cern

PWGJE/DataModel/EMCALClusters.h

@@ -49,11 +49,12 @@ const EMCALClusterDefinition kV3SmallestTimeDiff(ClusterAlgorithm_t::kV3, 42, 1,
 const EMCALClusterDefinition kV3MostSplitSmallTimeDiff(ClusterAlgorithm_t::kV3, 43, 1, "kV3MostSplitSmallTimeDiff", 0.5, 0.1, -10000, 10000, 500, true, 0., false);
 const EMCALClusterDefinition kV3MostSplitSmallerTimeDiff(ClusterAlgorithm_t::kV3, 44, 1, "kV3MostSplitSmallerTimeDiff", 0.5, 0.1, -10000, 10000, 100, true, 0., false);
 const EMCALClusterDefinition kV3MostSplitSmallestTimeDiff(ClusterAlgorithm_t::kV3, 45, 1, "kV3MostSplitSmallestTimeDiff", 0.5, 0.1, -10000, 10000, 50, true, 0., false);
+const EMCALClusterDefinition kV3MostSplitSmallestTimeDiffLowestSeed(ClusterAlgorithm_t::kV3, 50, 1, "kV3MostSplitSmallestTimeDiffLowestSeed", 0.1, 0.1, -10000, 10000, 50, true, 0., false);
 
 /// \brief function returns EMCALClusterDefinition for the given name
 /// \param name name of the cluster definition
 /// \return EMCALClusterDefinition for the given name
-const EMCALClusterDefinition getClusterDefinitionFromString(const std::string& clusterDefinitionName)
+inline const EMCALClusterDefinition getClusterDefinitionFromString(const std::string& clusterDefinitionName)
 {
   if (clusterDefinitionName == "kV3NoSplit") {
     return kV3NoSplit;
@@ -89,6 +90,8 @@ const EMCALClusterDefinition getClusterDefinitionFromString(const std::string& c
     return kV3MostSplitSmallerTimeDiff;
   } else if (clusterDefinitionName == "kV3MostSplitSmallestTimeDiff") {
     return kV3MostSplitSmallestTimeDiff;
+  } else if (clusterDefinitionName == "kV3MostSplitSmallestTimeDiffLowestSeed") {
+    return kV3MostSplitSmallestTimeDiffLowestSeed;
   } else {
     throw std::invalid_argument("Cluster definition name not recognized");
   }