Hi all.

I have the following problem and I would be really grateful if someone can give me a hint…

I have a script that performs an extended ml fit in two distributions. All well so far.

When I try to do it in RooSimultaneous way, the result of the first fit is behaving:
instead of RooAddPdf = Gauss + Expo
RooAddPdf = (Gauss + Expo) / 2

Any ideas??