About retrieving TTrees from a file

Hi ROOTers,

Recently I generated some flat Ntuples using the Ntuplemaker package in ATHENA. The same package had earlier generated Ntuples like this,

> root [5] _file1->ls()
> TFile** /cluster/data01/suvayu/ttbar.dilep.ntuple/mc08.105600.Pythia_Zprime_tt1000.detailed.root
> TFile* /cluster/data01/suvayu/ttbar.dilep.ntuple/mc08.105600.Pythia_Zprime_tt1000.detailed.root
> KEY: AttributeListLayout Schema;1
> KEY: TTree CollectionTree;1 CollectionTree

The latest root files I generated looks like this.

> root [3] _file0->ls()
> TFile** /cluster/data01/suvayu/ttbar.dilep.ntuple/mc08.105592.1TeV/detailedAOD.AAN.root
> TFile* /cluster/data01/suvayu/ttbar.dilep.ntuple/mc08.105592.1TeV/detailedAOD.AAN.root
> OBJ: TTree CollectionTree CollectionTree : 0 at: 0x87c8828
> KEY: AttributeListLayout Schema;1
> KEY: TTree CollectionTree;43 CollectionTree
> KEY: TTree CollectionTree;42 CollectionTree

These two trees are exactly the same when I plot any of the objects in there. I know this is not directly related to ROOT but still could any one shed some light on this?

TIA

-- 
Suvayu

Open source is the future. It sets us free.