Measuring anomalous WW$\gamma$ and t$\bar{\text{t}}\gamma$ couplings using top+$\gamma$ production at the LHC

Abstract

We consider the electroweak production of a top quark in association with a photon at the LHC to probe the electroweak top quark couplings (t$\bar{\text{t}}\gamma$) as well as the triple gauge boson couplings (WW$\gamma$). The study is based on the modifications of the t$\bar{\text{t}}\gamma$ and WW$\gamma$ interactions via heavy degrees of freedom in the form of dimension-six operators which we add to the standard model Lagrangian. A binned angular asymmetry in single top quark plus photon events and cross section ratio are proposed to probe the anomalous t$\bar{\text{t}}\gamma$ and WW$\gamma$ couplings. It is shown that the proposed angular asymmetry can distinguish anomalous t$\bar{\text{t}}\gamma$, WW$\gamma$ couplings from the standard model prediction and yield a great sensitivity.

Comments: 15 pages, 8 figures and 2 tables, published version