gDirectory->Get("electron_Pt") does not work for me

ROOT
1

To search a specific histogram in a root file, I tried gDirectory->Get(“electron_Pt”) but this does not work? The electron_Pt is exist in that root file but the command is not able to find it. Please suggest.

2 
gDirectory->ls();
3

Try also the command-line tool rootls. It’s possible that electron_Pt is a branch in a TTree, so you won’t be able to get it with gDirectory->Get().