  We consider a strongly interacting twin Higgs (SITH) model where an
ultraviolet completion of twin Higgs mechanism is realized by a strongly
coupled approximately scale invariant theory. Besides the Standard Model (SM)
and twin sectors, the low energy effective theory contains a relatively light
scalar called a dilaton --- the pseudo Goldstone boson of spontaneously broken
scale invariance. The dilaton provides a unique portal between the SM and twin
sectors whose phenomenology could provide an important probe of the twin Higgs
mechanism. As a concrete example, we consider a holographic twin Higgs model
where the role of the dilaton is played by the radion. The phenomenology of
this model is fully determined by a few parameters and our analysis concludes
that at the HL-LHC (14 TeV) and HE-LHC (27 TeV) with 3000/fb most of the
natural parameter space can be probed.
