Phenomenology of the radion in Randall-Sundrum scenario at colliders

Phenomenology of a radion ($\phi$) 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 ($\Lambda_{\phi}$) 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 $\phi$ -> g g, unlike the SM Higgs boson case. We also present constraints on the mass $m_{\phi}$ and the new scale $\Lambda_{\phi}$ from the Higgs search limit at LEP and perturbative unitarity bound.