Probe anomalous tq γ couplings through single top photoproduction at the LHC

摘要

In this work we study the constraints on the anomalous tq γ ( q = u , c ) couplings by photon-produced leading single top production and single top jet associated production through the main reactions pp → p γ p → pt → pW ( → ? ν ? ) b + X and pp → p γ p → ptj → pW ( → ? ν ? ) 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 < ξ 1 < 0.5 , 0.1 < ξ 2 < 0.5 and 0.0015 < ξ 3 < 0.15 with a luminosity of 2 fb ? 1 , the lower bounds of κ tq γ 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 B r ( t → q γ ) ～ 3 × 10 ? 5 . With a luminosity of 200 fb ? 1 , the lower bounds of κ tq γ are 0.0041 (0.0048), 0.0069 (0.0064) and 0.0042 (0.0051), respectively, corresponding to B r ( t → q γ ) ～ 4 × 10 ? 6 . We conclude that both channels can be used to detect such anomalous tq γ couplings and the detection sensitivity on κ tq γ is obtained.