macros/diskinematics_analysis/makePlot_truth_EtaDistribution.C

0001 int makePlot_truth_EtaDistribution(
0002                    const TString infile = "../../data/Sample_DISReco_ep.root",
0003                    //const TString infile = "../../data/EventGenAna_Pythia6_DIS_10x250_100k.root",
0004                    const bool save_figures = true
0005                                    )
0006 {
0007   gStyle->SetOptStat(kFALSE);
0008
0009   TFile *f_truth = new TFile( infile, "OPEN");
0010   TTree* t_truth = (TTree*)f_truth->Get("event_truth");
0011   t_truth->Print();
0012
0013   TCut electron_cut = "em_evtgen_pid == 11";
0014   TCut Pion_cut = "abs( em_evtgen_pid ) == 211";
0015
0016   TH1F *h_eta = new TH1F("h_eta", "", 60, -6, 6);
0017   TH1F *h_eta_e = (TH1F*)h_eta->Clone();
0018
0019   TCanvas *c_eta = new TCanvas("c_eta");
0020
0021   t_truth->Draw("-1 * log( tan( em_evtgen_theta / 2.0 ) ) >> h_eta", Pion_cut);
0022   h_eta->SetLineStyle(2);
0023   t_truth->Draw("-1 * log( tan( em_evtgen_theta / 2.0 ) ) >> h_eta_e", electron_cut, "sames");
0024
0025   h_eta->GetXaxis()->SetTitle("Pseudorapidity #eta");
0026   h_eta->GetYaxis()->SetTitle("dN/d#eta");
0027
0028   TLegend* leg_eta = new TLegend( 0.25, 0.70, 0.45, 0.90);
0029   leg_eta->AddEntry(h_eta, "Charged Pions", "L");
0030   leg_eta->AddEntry(h_eta_e, "Electrons", "L");
0031   leg_eta->Draw();
0032
0033   if ( save_figures )
0034     {
0035       c_eta->Print("plots/truth_EtaDistribution.eps");
0036       c_eta->Print("plots/truth_EtaDistribution.png");
0037     }
0038
0039   return 0;
0040 }