Performance of Impact Parameter-Based b-tagging Algorithms with the ATLAS Detector using Proton-Proton Collisions at √s = 7 TeV

The ability to identify jets containing $b$-hadrons is important for the high-pt physics program of a general-purpose experiment at the LHC such as ATLAS. Two tagging algorithms taking advantage of the accurate measurement of the transverse impact parameter of charged tracks measured in the ATLAS Inner detector have been developed and are particularly important for early data. The behavior of these algorithms is studied in the early 7 TeV collision data recorded in 2010, corresponding to an integrated luminosity of about 15 nb-1, and are found to compare well with expectations from Monte Carlo simulation.