Prospects for associated single top quark production cross section measurements in the dilepton decay mode with ATLAS

In addition to providing direct access to the CKM matrix parameter Vtb, single top quark production is also sensitive to the existence of new heavy gauge bosons, flavor-changing neutral current interactions and various other new physics phenomena. This report outlines the prospects for measurements of the associated (Wt-channel) single top quark production cross section in the dilepton decay mode with the ATLAS detector. All major backgrounds and sources of uncertainty are taken into account, and the performance of a simple cut-based analysis and an optimized analysis based on boosted decision trees are compared for two levels of integrated luminosity at sqrt(s) = 14 TeV. Relative errors on the cross section of 34% and 12% are found for integrated luminosities of 1 fb-1 and 10 fb-1, respectively. Despite its small cross section, this channel thus appears quite promising for the first few years of ATLAS running thanks to its clean dilepton signature and lack of dependence on b-tagging for the suppression of non-top backgrounds.