# Search for anomalous $\boldmath{Wtb}$ couplings in single top quark production

Abstract : In 0.9 fb$^{-1}$ of $p \bar p$ collisions, D0 has observed an excess of events with an isolated lepton, missing transve rse momentum, and two to four jets. This excess is consistent with single top quark production. We examine these data to study the Lorentz structure of the $Wtb$ coupling. The standard model predicts a left-handed vector coupling at the $Wt b$ vertex. The most general lowest dimension, CP-conserving Lagrangian admits right-handed vector and left- or right-h anded tensor couplings as well. We find that the data prefer the left-handed vector coupling and set upper limits on the anomalous couplings. These are the first direct constraints on a general $Wtb$ interaction and the first direct limits on left- and right-handed tensor couplings.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00295010
Contributor : Emmanuelle Vernay <>
Submitted on : Friday, July 11, 2008 - 8:41:42 AM
Last modification on : Thursday, November 19, 2020 - 12:58:50 PM

### Citation

V.M. Abazov, B. Abbott, M. Abolins, B.S. Acharya, M. Adams, et al.. Search for anomalous $\boldmath{Wtb}$ couplings in single top quark production. Physical Review Letters, American Physical Society, 2008, 101, pp.221801. ⟨10.1103/PhysRevLett.101.221801⟩. ⟨in2p3-00295010⟩

Record views