  In the Randall-Sundrum model, the radion-Higgs mixing is weakly suppressed by
the effective electroweak scale. One of its novel features would be a sizable
three-point vertex of KK graviton-Higgs-radion. We explored the potential of
the Fermilab Tevatron and the CERN LHC in probing the radion-Higgs mixing via
the associated production of the radion with the Higgs boson. The observation
of the rare decay of the KK gravitons into a Higgs and a radion is then the
direct and exclusive signal of the radion-Higgs mixing. We also studied all the
partial decay widths of the KK gravitons in the presence of the radion-Higgs
mixing, and found that if the mixing parameter is of order one, the decay rate
into a radion and a Higgs boson becomes as large as that into a Higgs boson
pair, with the branching ratio of order 0.001.
