Dear RooFit experts,
I am trying to fit mass distributions in different pT bins.
for (int pt = 0; pt < 13; pt++) {
RooRealVar x(...);
RooRealVar mean(...);
x.setRange(...);
RooRealVar sigma1(...);
RooRealVar sigma2(...);
RooRealVar sig1(...);
RooRealVar sig2(...);
RooGaussian gaus1(...);
RooGaussian gaus2(...);
RooDataHist data(...);
RooRealVar ap(...);
RooRealVar bp(...);
RooRealVar cp(...);
RooRealVar dp(...);
RooChebychev poly(...);
RooRealVar polysig(...);
RooAddPdf sum("sum","sum",RooArgList(gaus1,gaus2,poly),RooArgList(sig1,sig2,polysig));
sum.fitTo(data, ...);
}
I found some pt=11 and 12 are very messed up.
However, if I set pt start from 11 or 12, the fit is actually very good.
So I wonder, does roofit has memory of fitting history?
That’s the only thing I can think of to mess up the fit.
Thanks,