// pdf components for model

RooHistPdf RxFF_comp{*RxHistPdf_FF, "RxFF_comp"};
RooFFTConvPdf FBx_FF("FBx_FF", "FBx_FF", *X, CsiB, *RxHistPdf_FF);

Fsig_FF = new RooAddPdf("Fsig_FF","Fsig_FF",RooArgList(FBx_FF,RxFF_comp),RooArgList(N_nonprompt, N_prompt));

RooProdPdf Signal_FF("Signal_FF","Signal_FF",RooArgList(*Msig_FF,*Fsig_FF));

RooProdPdf Bkg_FF("Bkg_FF","Bkg_FF",RooArgList(*Mbkg_FF, *FBkg_FF ));


RooProdPdf Bkg_FF_LB1("Bkg_FF_LB1","Bkg_FF_LB1",RooArgList(*Mbkg_FF, *FbkgSideBandsFF[0]));
RooProdPdf Bkg_FF_LB2("Bkg_FF_LB2","Bkg_FF_LB2",RooArgList(*Mbkg_FF, *FbkgSideBandsFF[1]));
RooProdPdf Bkg_FF_RB1("Bkg_FF_RB1","Bkg_FF_RB1",RooArgList(*Mbkg_FF, *FbkgSideBandsFF[2]));
RooProdPdf Bkg_FF_RB2("Bkg_FF_RB2","Bkg_FF_RB2",RooArgList(*Mbkg_FF, *FbkgSideBandsFF[3]));	

RooAddition Nsig("Nsig","number of signal events",RooArgList(N_nonprompt,N_prompt)) ;
RooRealVar Nbkg("Nbkg","number of background events",500,0,1e9);

RooAddPdf* Model_FF_SIG = new RooAddPdf("Model_FF_SIG", "Model_FF_SIG", RooArgSet(Signal_FF, Bkg_FF), RooArgList(Nsig,Nbkg)); 
RooAddPdf* Model_FF_LB1 = new RooAddPdf("Model_FF_LB1", "Model_FF_LB1", RooArgSet(Signal_FF, Bkg_FF_LB1), RooArgList(Nsig,Nbkg));
RooAddPdf* Model_FF_LB2 = new RooAddPdf("Model_FF_LB2", "Model_FF_LB2", RooArgSet(Signal_FF, Bkg_FF_LB2), RooArgList(Nsig,Nbkg));
RooAddPdf* Model_FF_RB1 = new RooAddPdf("Model_FF_RB1", "Model_FF_RB1", RooArgSet(Signal_FF, Bkg_FF_RB1), RooArgList(Nsig,Nbkg));
RooAddPdf* Model_FF_RB2 = new RooAddPdf("Model_FF_RB2", "Model_FF_RB2", RooArgSet(Signal_FF, Bkg_FF_RB2), RooArgList(Nsig,Nbkg));

// Category defining 
   RooCategory sample("sample", "sample");
   sample.defineType("Sigff");
   sample.defineType("LB1ff");
   sample.defineType("LB2ff");
   sample.defineType("RB1ff");
   sample.defineType("RB2ff");

// -------- Data labeling -------------
std::map<std::string, RooDataSet *> mapUB_;
	mapUB_["Sigff"] =  data_ff_xSig;
	mapUB_["LB1ff"] =  data_ff_LB1;
	mapUB_["LB2ff"] =  data_ff_LB2;
	mapUB_["RB1ff"] =  data_ff_RB1;
	mapUB_["RB2ff"] =  data_ff_RB2;

// model for simultaneous fit
	RooSimultaneous simPdf("simPdf", "simultaneous pdf", sample);
   simPdf.addPdf(*Model_FF_SIG, "Sigff");
   simPdf.addPdf(*Model_FF_LB1, "LB1ff");
   simPdf.addPdf(*Model_FF_LB2, "LB2ff");
   simPdf.addPdf(*Model_FF_RB1, "RB1ff");
   simPdf.addPdf(*Model_FF_RB2, "RB2ff");

RooDataSet combData("combData", "combined data", RooArgSet(Mass,*X), Index(sample), Import(mapUB_));

// Fitting here 
RooFitResult * fitres = simPdf.fitTo(combData, Save(kTRUE));