Phenomenology of the radion in Randall-Sundrum scenario at colliders

Abstract

Phenomenology of a radion ($ϕ$) that stabilizes the modulus in the Randall-Sundrum scenario is considered. The radion couples to the trace of energy momentum tensor of the standard model (SM) with a strength suppressed only by a new scale ($Λ_ϕ$) of an order of the electroweak scale. In particular, the effective coupling of a radion to two gluons are enhanced due to the trace anomaly of QCD. Therefore, its production cross section at hadron colliders could be enhanced, and the dominant decay mode of a relatively light radion is $ϕ$ -> g g, unlike the SM Higgs boson case. We also present constraints on the mass $m_ϕ$ and the new scale $Λ_ϕ$ from the Higgs search limit at LEP and perturbative unitarity bound.