Phenomenology of the radion in the 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 is 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 --> gg, 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. (C) 2000 Elsevier Science B.V. All rights reserved.