  This article reviews some recent work on a version of the standard model (the
Lee-Wick standard model) that contains higher derivative kinetic terms that
improve the convergence of loop diagrams removing the quadratic divergence in
the Higgs boson mass. Naively higher derivative theories of this type are not
acceptable since the higher derivative terms either cause instabilities (from
negative energies) or a loss of unitarity (from negative norm states). Lee and
Wick provided an interpretation for such theories arguing that theories with
higher derivative kinetic terms can be unitary and stable if the states
associated with the massive propagator poles, that arise from the higher
derivatives, have widths and hence decay and are not in the spectrum of the
theory.
