Eur. Phys. J. C (2007) 51: 919-926
https://doi.org/10.1140/epjc/s10052-007-0344-1

Regular Article - Theoretical Physics

FCNC top quark decays in extra dimensions

¹ Instituto de Física, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
² Departamento de Física, Universidad Nacional de Colombia, Bogotá, Colombia

^* e-mail: jarodriguezl@unal.edu.co

Received: 7 February 2007
Revised: 18 May 2007
Published online: 1 August 2007

Abstract

The flavor changing neutral top quark decay t→cX is computed, where X is a neutral standard model particle, in an extended model with a single extra dimension. The cases for the photon, X=γ, and a standard model Higgs boson, X=H, are analyzed in detail in a non-linear R_ξ gauge. We find that the branching ratios can be enhanced by the dynamics originating in the extra dimension. In the limit where 1/R≫m_t, we have found Br(t→cγ)≃10^-10 for 1/R = 0.5 TeV. For the decay t→cH, we have found Br(t→cH)≃10^-10 for a low Higgs mass value. The branching ratios go to zero when 1/R→∞.