How to get the data for only one branch

Newbie
5 
std::unique_ptr<TFile> myFile(TFile::Open("RAW148OS_treeFF01.root", "READ"));
auto tree = myFile->Get<TTree>("Analysis_All");   


int variable;
tree->SetBranchAddress("Fragment_Velocity", &variable);

for (int iEntry = 0; tree->LoadTree(iEntry) >= 0; ++iEntry) {
   // Load the data for the given tree entry
   tree->GetEntry(iEntry);

   // Now, `variable` is set to the value of the branch
   // "branchName" in tree entry `iEntry`
   std::cout << variable << std::endl;
}

Is it better now ?