const int NFoils = 2;

const Double_t z0 = -15.32e-3, dz = 75e-3;
const Double_t targetfoils[NFoils]={
  z0 - dz,
  z0 + dz
};

void FitVertex(void){

  TH1F * react_z = new TH1F("react_z","react_z",600,-0.2,0.2);

  T->Draw("rpl.z>>react_z","abs(rpl.z)<0.2");
  TLine *z_ideal[NFoils];
  TF1 *gr[NFoils];
  char name[NFoils][300] = {"m1","m2"};


  for(int i=0;i<NFoils;i++){
    z_ideal[i] = new TLine(targetfoils[i],0,targetfoils[i],0.0);
    z_ideal[i]->SetLineColor(3);
    z_ideal[i]->Draw("same");
    gr[i] = new TF1(name[i],"gaus",targetfoils[i]-dz/2.,targetfoils[i]+dz/2.);
  }


  TF1 *total = new TF1("mtotal","gaus(0)+gaus(3)",targetfoils[0]-dz/2.0,targetfoils[NFoils-1]+dz/2.0);
  Double_t par[3*NFoils];


  react_z->Fit(gr[0],"R");
  react_z->Fit(gr[1],"R+");

  gr[0]->GetParameters(&par[0]);
  gr[1]->GetParameters(&par[3]);

  total->SetParameters(par);
  react_z->Fit(total,"R+");

}