  The scattering theory of Lax and Phillips, originally developed to describe
resonances associated with classical wave equations, has been recently extended
to apply as well to the case of the Schroedinger equation in the case that the
wave operators for the corresponding Lax-Phillips theory exist. It is known
that the bound state levels of an atom become resonances (spectral
enhancements) in the continuum in the presence of an electric field (in all
space) in the quantum mechanical Hilbert space. Such resonances appear as
states in the extended Lax-Phillips Hilbert space. We show that for a simple
version of the Stark effect, these states can be explicitly computed, and
exhibit the (necessarily) semigroup property of decay in time. The widths and
location of the resonances are those given by the poles of the resolvent of the
standard quantum mechanical form.
