Single-top production and rare top interactions

Abstract

The study of the top quark's properties is an important part of the LHC programme. In earlier work, we have studied the rare decay $t\to b\bar{b}c$, using effective operators to capture the effects of physics beyond the Standard Model. However top decay is primarily sensitive to new physics in the sub-TeV energy regime. If this new physics resides at a higher energy scale, then one needs to turn to single-top production. In this paper, we use the $s$-channel and $t$-channel single-top production measurements to constrain the new physics parameter space associated with such contact interactions. We also study the net top polarization as a means to distinguish between contributions from operators involving different fermion chiralities and Lorentz structures.

Comments: Version published in Physical Review D