Commissioning of b-jet identification with pp collisions at sqrt(s) = 7 TeV

The identification of jets containing the weak decay of a b hadron is an essential tool for a wide range of physics analyses in the context of the Standard Model and beyond. A variety of algorithms exploit the long lifetime and the presence of decay leptons to discriminate these jets from those associated with gluons and light quarks. The distributions of the corresponding observables - track impact parameters, secondary vertices and lepton momenta - were measured in pp collisions at $\sqrt{s}$ = 7\ TeV and found to be in agreement with the predictions of Monte Carlo simulation. First results on efficiencies and mis-identification rates are shown.