Normalizing TH2F

Dear Rooters,
How can I normalize histogram TH2F using Branches? I using the code below:

TFile ff("roottree_2E2mu_1TeV.root");
TTree *MyTree=HZZ4LeptonsAnalysis;

TH2F *hSignalYEEmm = new TH2F("hSignalYEEmm","Z'#rightarrowYY#rightarrow e^{+}e^{+}#mu^{-}#mu^{-}",50,100.,360.,50,100.,360.);
MyTree->Project("hSignalYEEmm","RECO_MASS[1]:RECO_MASS[2]");
hSignalYEEmm->SetYTitle("m_{#mu^{-}#mu^{-}} (GeV/c^{2})");
hSignalYEEmm->SetXTitle("m_{e^{+}e^{+}} (GeV/c^{2})");
hSignalYEEmm->Draw("lego2");

Please, could you help me?

Best Regards,
Sandro Fonseca de Souza
PhD Student
UERJ/Brazil