Searches in s-channel single top quark production at ATLAS

We present the results of two searches in s-channel single top-quark production at 7 TeV proton-proton collisions with the ATLAS detector at the Large Hadron Collider. The analyses use the same event selection and background estimation techniques. An observed (expected) upper limit at 95% C.L. on the s-channel single top-quark production cross-section of sigma < 26.5 (20.5) pb is obtained using a cut-based analysis. The result of the tb resonances search in the same final state is also given. This result is translated into a lower bound on the allowed right-handed W'_R mass, giving m_{W'_R} > 1.13 TeV at 95% C.L.