Radion vacuum expectation value and graviton mass: a study in an Einstein–Gauss–Bonnet warped geometry scenario

Abstract

In the usual 5-dimensional Randall–Sundrum scenario with warped geometry of the extra compact dimension, the Goldberger–Wise mechanism for stabilisation of the radius of compactification can lead to a scalar field called the radion. The radion can have implications in TeV-scale physics, which can be especially noticeable if its vacuum expectation value (vev) is not far above a TeV. However a large mass of the first graviton excitation, which seems to be suggested by recent search limit, tends to make the radion vev, far too large in the minimal model. We show that this is not the case if a Gauss–Bonnet term, containing higher powers of the curvature, is present in the 5-dimensional action. As a result, a radion with vev in the range 1.7–4.0 TeV can be consistent with the first graviton excitation mass well above the bound set by LHC experiments.