Hi Enrico,
thank you for the prompt reply.
Following the example you pointed me to, I should first of all determine the indices of the good muons, i.e. the indices of the muons with Muon_pt>0.5 and Muon_eta>2.4.
Is there a faster way to filter?
I was having a look at another topic.
Following one of the answers, it seems that something like (in C++?)
df.Filter("! Muon_pt[Muon_pt > 0.5].empty()").Filter("! Muon_eta[Muon_eta > 2.4].empty()")
should do the same job, right?