{
//sest xlab:
//h->GetYaxis()->SetTitleOffset(nb);
//ou gStyle->SetTitleOffset(factor, "Y"); ou minuscule

gROOT->Reset();

TCanvas *c1=new TCanvas("c1","Copy Paste",200,200,800,600);
c1->Range(1,1,1000,1000);
c1->SetLogy();
c1->SetLogx();

Double_t higgs_mass_gamgam[8]={80.,90.,100.,110.,120.,130.,140.,150.};
Double_t signi_higgs_gamgam_high_lumi_TDR[8]={2.4,3.1,4.4,5.6,6.5,6.5,5.8,4.3};
Double_t signi_higgs_gamgam_low_lumi_TDR[8]={1.5,1.9,2.7,3.4,3.9,4.0,3.5,2.6};

TGraph *graph_higgs_gamgam=new TGraph(8,higgs_mass_gamgam,signi_higgs_gamgam_high_lumi_TDR);
graph_higgs_gamgam->SetTitle("signal significance");

TMultiGraph *multigraph=new TMultiGraph();
multigraph->Add(graph_higgs_gamgam);

multigraph->Draw("ACP");// in root, titles and limits must be due after the draw function
multigraph->GetXaxis()->SetLimits(60.,5000.);
multigraph->GetYaxis()->SetLimits(1.,1000.); // THIS DOESN'T WORK WHY ?

multigraph->GetXaxis()->SetTitle("m_{H} (GeV)");
multigraph->GetYaxis()->SetTitle("Signal significance");
multigraph->Draw("ACP");// in root, titles and limits must be due after the draw function

//c1->Modified();
}