  The \mu parameter of the supersymmetric standard model is replaced by \lambda
S, where S is a singlet chiral superfield, introducing a Peccei--Quinn symmetry
into the theory. Dynamics at the electroweak scale naturally solves both the
strong CP and \mu problems as long as \lambda is of order \sqrt{M_Z /M_pl} or
smaller, and yet this theory has the same number of relevant parameters as the
supersymmetric standard model. The theory will be tested at colliders: the \mu
parameter is predicted and there are long-lived superpartners that decay to
gravitinos or axinos at separated vertices. To avoid too much saxion cold dark
matter, a large amount of entropy must be produced after the electroweak phase
transition. If this is accomplished by decays of a massive particle, the reheat
temperature should be no more than a GeV, strongly constraining baryogenesis.
Cold dark matter may be composed of both axions, probed by direct detection,
and saxions, probed by a soft X-ray background arising from decays to \gamma
\gamma. There are two known possibilities for avoiding problematic axion domain
walls: the introduction of new colored fermions or the assumption that the
Peccei--Quinn symmetry was already broken during inflation. In the first case,
in our theory the colored particles are expected to be at the weak scale, while
in the second case it implies a good chance of discovering isocurvature
perturbations in the CMB radiation and a relatively low Hubble parameter during
inflation.
