Probe anomalous tqγ couplings through single top photoproduction at the LHC

In this work we study the constraints on the anomalous tq gamma (q = u, c) couplings by photon-produced leading single top production and single top jet associated production through the main reactions pp -> p gamma p -> Pt -> pW(-> l nu(l))b + X and pp -> p gamma p -> ptj -> pW(-> l nu(t))bj + X assuming a typical LHC multipurpose forward detectors in a model independent effective lagrangian approach. Our results show that: for the typical detector acceptance 0.0015 < xi(1) < 0.5, 0.1 < xi(2) < 0.5 and 0.0015 < xi(3) < 0.15 with a luminosity of 2 fb(-1), the lower bounds of kappa(tq gamma) through leading single top channel (single top jet channel) are 0.0130 (0.0156), 0.0218 (0.0206) and 0.0133 (0.01655), respectively, corresponding to Br(t -> q gamma) similar to 3 x 10(-5). With a luminosity of 200 fb(-1), the lower bounds of kappa(tq gamma) are 0.0041 (0.0048), 0.0069 (0.0064) and 0.0042 (0.0051), respectively, corresponding to Br(t -> q gamma) similar to 4 x 10(-6). We conclude that both channels can be used to detect such anomalous tq gamma couplings and the detection sensitivity on kappa(tq gamma) is obtained. (C) 2014 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/).