I want to do a simultaneous fit of 2 samples: positive and negative. My pdf is a product of mass pdf and angles pdf. My purpose is to perform a simultanous fit of the angles in bins of the mass.
I reproduce this case with a simple root script (in attachment) inspired by this tutorial:
root.cern.ch/root/html534/tutori … ool.C.html
The fit works well. Now, I want to split the parameter “mean” ,shared by the positive and negative pdf, in bins of mass. The fit failed and I got strange values. You can find the complete output in attachment.
Do I miss something?