Search for anomalous Wtb couplings in single top quark production in pp collisions at √ s = 1.96 TeV

We present new direct constraints on a general Wtb interaction using data corresponding to an integrated luminosity of 5.4 fb−1 collected by the D0 detector at the Tevatron p¯p collider. The standard model provides a purely left-handed vector coupling at the Wtb vertex, while the most general, lowest dimension Lagrangian allows right-handed vector and left- or right-handed tensor couplings as well. We obtain precise limits on these anomalous couplings by comparing the data to the expectations from different assumptions on the Wtb coupling.