RooFit normalization

Dear friends,

I have an issue with the normalization of the fitted function. I know that the normalization of the PDF is automatically adjusted to the number of events. So far so good.

The problem is when I fit twice** the same data with the same PDF, it looks like the normalization gets a factor 2 x the number of events (see attachment). Is there a way to get rid of that factor 2 ?


** Why do I want to fit twice? Well, in the first pass I fixed some parameter and in the second I release it.

Duplication of

See answers there