I have a 5-dimensional PDF in root (more specifically, I have created that PDF by combining RooAbsReal objects through RooRealSumPdf). In one of the dimensions, there is a long tail and there are very small amount of events at the last few bins. I tried fitting that PDF to the “correct data”, but it turns out that there’s something wrong with the very last few bins: the PDF (in red) slopes down below what it is supposed to be (the correct values are in black). I’m not sure what could be causing this: I have already made sure that there are no empty bins at all by putting in a very small value even for the empty bins. May I ask how to debug this?
_ROOT Version: v16.6
_Platform: lxplus (centos7)
Compiler: Not Provided