The program crash after all sentences have been executed

ROOT
5

Hmm, interesting. Your slewing.cpp can be reduced to just four lines of code and still it will segfault:

void simplified()
{
        TFile datafile("t0_RUN1_timing.root", "read");
        TTree *tree = datafile.Get<TTree>("time");
        for (Long64_t ev = 0; ev < tree->GetEntries(); ev++)
                tree->GetEntry(ev);
}

I haven’t seen this before. The same four lines of code work for any of my own files with a TTree (given, of course, that I change the file name and the TTree name).