I am doing a simultaneous fit to an invariant mass line shape as a function of mass of a pseudoscalar higgs (M_a). The fit is a Gaussian plus Landau and the mean and width of each are extracted from a linear fit. Is there a way to get roofit to spit back the parameters for a given M_a? What I do now is
frSim = wks->pdf("pdfSim")->fitTo(*dataSimT,RooFit::Save());
which gives me the slope and intercept for the linear fits. But when I use those to reconstruct the Gaussian+Landau at a given M_a, it comes out a bit different from what Roofit plots with
Any suggestions are much appreciated.