Resolve "pi0 resolution for ECal barrel"

Closes #19 (closed)

benchmarks/barrel_ecal/scripts/emcal_barrel_pions_analysis.cxx

@@ -129,7 +129,7 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
   };
 
   // Thrown Energy [GeV]
-  auto Ethr = [](std::vector<dd4pod::Geant4ParticleData> const& input) {
+  auto  charge = [](std::vector<dd4pod::Geant4ParticleData> const& input) {
     std::vector<double> result;
     result.push_back(input[2].charge);
   return result;
@@ -143,7 +143,7 @@ void emcal_barrel_pions_analysis(const char* input_fname = "sim_output/sim_emcal
         .Define("fsam",   fsam2,      {"Esim","Ethr"})
         .Define("dE",     eResol,     {"Esim", "Ethr"})
         .Define("dE_rel", eResol_rel, {"Esim", "Ethr"})
-        .Define("charge", {"mcparticles"})
+        .Define("charge", charge,     {"mcparticles"})
 	      ;
 
   // Define Histograms