void ThetaRes(TString path = "/panda/myResults/G4_ph_lists/BOX_2_12mrad_G4_FTF_BERT_"){
  // const int npmom=5;
  // double Pbeam[npmom]={1.5,4.06,8.9,11.91,15};
  // TString Pbeam_str[npmom] = {"/mom_1_5/","/mom_4_06/","/mom_8_9/","/mom_11_91/","/mom_15/"};
  const int npmom=1;
  double Pbeam[npmom]={1.5};
  TString Pbeam_str[npmom] = {"/mom_1_5/"};

  TString path_noCut = path+"noCut/";
  TString path_BoxCut = path+"BoxCut/";
  TString path_XYCut = path+"XYCut/";
  const int nmethods=3;
  TH1 *hth_mean[nmethods];   TH1 *hth_rms[nmethods];
  for(int qb=0;qb<npmom;qb++){//loop over Pbeam
    int imeth=0;

    TString fname_noCut = path_noCut;
    fname_noCut+=Pbeam_str[qb];
    fname_noCut +="/Lumi_QA_SUM.root";
    TFile *fin_noCut = new TFile(fname_noCut,"READ");
    if(fin_noCut->IsZombie()) cout<<"File: "<<fname_noCut<<" =("<<endl;
    //   TH2D *hth_th0 = (TH2D*)fin_noCut->Get("NearIP/hResTheta_th");
    TH2D *hth_th0 = (TH2D*)fin_noCut->Get("NearIP/hResTheta_ph");
    hth_th0->FitSlicesY();
    hth_mean[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_1");
    hth_rms[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_2");
    hth_mean[imeth]->SetMarkerStyle(20);
    hth_rms[imeth]->SetMarkerStyle(20);
    hth_mean[imeth]->GetYaxis()->SetTitle("mean(#theta_{MC}-#theta_{REC}), mrad");
    hth_mean[imeth]->SetMarkerColor(2);
    hth_rms[imeth]->SetMarkerColor(2);
    hth_rms[imeth]->GetYaxis()->SetTitle("sigma(#theta_{MC}-#theta_{REC}), mrad");
    hth_mean[imeth]->SetMarkerSize(2.5);
    hth_rms[imeth]->SetMarkerSize(2.5);
    imeth++;

    TString fname_BoxCut = path_BoxCut;
    fname_BoxCut+=Pbeam_str[qb];
    fname_BoxCut +="/Lumi_QA_SUM.root";
    TFile *fin_BoxCut = new TFile(fname_BoxCut,"READ");
    if(fin_BoxCut->IsZombie()) cout<<"File: "<<fname_BoxCut<<" =("<<endl;
    TH2D *hth_th1 = (TH2D*)fin_BoxCut->Get("NearIP/hResTheta_ph");
    hth_th1->FitSlicesY();
    hth_mean[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_1");
    hth_rms[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_2");
    hth_mean[imeth]->SetMarkerStyle(20);
    hth_rms[imeth]->SetMarkerStyle(20);
    hth_mean[imeth]->SetMarkerColor(37);
    hth_rms[imeth]->SetMarkerColor(37);
    hth_mean[imeth]->SetMarkerSize(2.5);
    hth_rms[imeth]->SetMarkerSize(2.5);
    imeth++;

    TString fname_XYCut = path_XYCut;
    fname_XYCut+=Pbeam_str[qb];
    fname_XYCut +="/Lumi_QA_SUM.root";
    TFile *fin_XYCut = new TFile(fname_XYCut,"READ");
    if(fin_XYCut->IsZombie()) cout<<"File: "<<fname_XYCut<<" =("<<endl;
    TH2D *hth_th2 = (TH2D*)fin_XYCut->Get("NearIP/hResTheta_ph");
    hth_th2->FitSlicesY();
    hth_mean[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_1");
    hth_rms[imeth] = (TH1D*)gDirectory->Get("hResTheta_ph_2");
    hth_mean[imeth]->SetMarkerStyle(20);
    hth_rms[imeth]->SetMarkerStyle(20);
    hth_mean[imeth]->SetMarkerColor(4);
    hth_rms[imeth]->SetMarkerColor(4);
    hth_mean[imeth]->SetMarkerSize(2.5);
    hth_rms[imeth]->SetMarkerSize(2.5);
    //    imeth++;

  }

  // hth_mean[0] ->Draw();
  // hth_mean[1] ->Draw("same");
  // hth_mean[2] ->Draw("same");
  hth_rms[0] ->Draw();
  hth_rms[1] ->Draw("same");
  hth_rms[2] ->Draw("same");


 TLegend *leg2 = new TLegend(0.15,0.84,0.3,0.99);
 TString momName = " ";
 // momName +=Pbeam[0];
 momName +="1.5";
 momName += " GeV/c";
 leg2->SetHeader(momName.Data());
  leg2->SetTextAlign(12);
  leg2->SetTextSize(0.03);
  leg2->SetFillColor(0);
  leg2->AddEntry(hth_mean[0],"no Cut","pe");
  leg2->AddEntry(hth_mean[1],"Box Cut","pe");
  leg2->AddEntry(hth_mean[2],"X&Y Cut","pe");

 leg2->Draw();

}