  The quadratic divergences of the Higgs mass may be cancelled either
accidentally or by the exchange of some new particles. Alternatively its impact
on naturalness may be weakened by raising the Higgs mass, which requires
changing the Standard Model below its natural cut-off. We show in detail how
this can be achieved, while preserving perturbativity and consistency with the
electroweak precision tests, by extending the Standard Model to include a
second Higgs doublet that has neither a vev nor couplings to quarks and
leptons. This Inert Doublet Model yields a perturbative and completely natural
description of electroweak physics at all energies up to 1.5 TeV. The discrete
symmetry that yields the Inert Doublet is unbroken, so that Dark Matter may be
composed of neutral inert Higgs bosons, which may have escaped detection at
LEP2. Predictions are given for multilepton events with missing transverse
energy at the Large Hadron Collider, and for the direct detection of dark
matter.

High Energy Physics - Phenomenology