Measurement of the top quark pair production cross section in pp collisions at √s = 7 TeV in dilepton final states with ATLAS

A measurement of the production cross section of top quark pairs in proton-proton collisions at a center-of-mass energy of 7~TeV recorded with the ATLAS detector at the Large Hadron Collider is reported. Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. Using a data sample corresponding to an integrated luminosity of 690 pb-1, a t-tbar production cross section of sigma = 177 \pm 6 (stat)^{+17}_{-14} (sys) \pm 8 (lum)pb is measured for an assumed top mass of m_t=172.5~GeV. A second measurement requiring at least one jet consistent with arising from a b~quark yields sigma = 183 \pm 6 (stat)^{+18}_{-14} (sys)^{+8}_{-7} (lum) pb. These measurements are in good agreement with each other and with Standard Model predictions.