Single Top Quark Production at D{O}

We present new measurements of the single top quark production cross section in \ppbar collisions at $\sqrt{s} = 1.96 TeV$ using data corresponding to 5.4 \ifb of integrated luminosity collected by the {\dzero} detector at the Fermilab Tevatron collider. The large mass of the top quark, close to the electroweak symmetry-breaking scale, makes it a good candidate for probing physics beyond the Standard Model, including possible anomalous couplings. We examine the data to study the Lorentz structure of the $Wtb$ coupling, and find that the data prefer the left-handed vector coupling, and set upper limits on the anomalous couplings.