{
  gROOT->Reset();
  gROOT->ProcessLine("#include <utility>");
  gSystem->Load("STLDictionary.so");

  string unitPTTau("Visible gen p_{T}^{#tau} (GeV)");
  string unitPTMu("Gen p_{T}^{#mu} (GeV)");
  string unitEtaTau("Visible gen #eta^{#tau}");
  string unitEtaMu("Gen #eta^{#mu}");
  string unitDR("#DeltaR(visible gen #tau, gen #mu)");

  map<string, pair<string, string> > effHistMap;
  effHistMap["muHadPFTauMatchVisibleGenPT"] = 
    make_pair(string("muHadVisibleGenPT"), unitPTTau);
}