Probing anomalous top quark couplings at eγcolliders

Abstract

We study in the effective Lagrangian approach the possibility of probing anomalous top quark charged current couplings in the single top production at a high energy eγcollider. We analyzed all possible dimension-six CP-conserving operators which can give rise to an anomalous Wtb coupling which represent new physics effect generated at a higher energy scale. For those operators which also give rise to anomalous Zbb_bar or right-handed Wtb couplings, we find that they are strongly constrained by the existing R_b and b->sγdata. As a result, a collider with a luminosity of the order of 100 fb^{-1} is required to observe the anomalous effects. For other operators which currently subject to no strong constraints, the high energy eγcollider can probe their couplings effectively because of the clean environment of such a collider.