Prospects for measuring $V_{tb}$ via s-channel single top at ATLAS

The production of single top quarks via the electroweak interaction promises to provide new opportunities to both test the standard model and search for new physics. In particular, electroweak top production provides the only means to directly measure the CKM matrix element V /sub tb/ at ATLAS. The s-channel has the lowest rate, but is the best theoretically understood mechanism of electroweak top production. An evaluation of the potential for background suppression and V/sub tb/ measurement in this channel is presented. It is found that significant background suppression can be achieved and V/sub tb/ can be measured in the s-channel to a statistical precision of 2.8% after taking three years of low luminosity data (3*10/sup 4/ pb/sup -1/) at the Large Hadron Collider. (20 refs).