HistFitter, exclusion fit: Upper Limit in shape fit

Dear ROOT forum,

i am using HistFitter in an exclusion fit and trying to get an upper limit on the model. I have 2 signal regions and both are binned in one variable. I am running as ‘HistFitter -F excl -l’ (-l tells the HistFitter to calculate the upper limit)

HistFitter seems to fail for this setup: i am not sure, but maybe the upper limit calculation works only for 1 signal region which is 1-binned (cut and count)? Does someone know maybe?

Thanks

Hi,

HistFitter is not part of ROOT, it is a specific tool used by Atlas. I am not sure we can really help you here. You should maybe contact directly the authors

Cheers

Lorenzo