ep - p h / 99 05 46 4 v 1 2 4 M ay 1 99 9 OSU - HEP - 99 - 03 CTP - TAMU

We analyze CP violation in the supersymmetric standard model (MSSM) embedded minimally into a left–right symmetric gauge structure with the seesaw mechanism for neutrino masses. With the plausible assumption of universal scalar masses it is shown that CP violation in the hadron sector of the MSSM is described by a single phase residing in the supersymmetry breaking Lagrangian. This improves the CP properties of the MSSM by providing a natural solution to the SUSY CP problem. Furthermore, ǫ/ǫ vanishes in this model above the seesaw scale; extrapolation to the weak scale then leads to a prediction in agreement with the NA31 and the recent KTeV observations. The electric dipole moment of the neutron is naturally suppressed, we estimate its magnitude to be about 4 × 10−29 ecm. Additional predictions include a tightly constrained super particle spectrum and vanishingly small CP asymmetries in the B meson system. Recent evidences for neutrino oscillations imply that the standard model must be extended to accommodate small neutrino masses. An elegant model that provides an explanation of the small neutrino masses via the seesaw mechanism [1] is the left-right symmetric model of weak interaction. Two seemingly unrelated puzzles of the standard model, viz., the stability of the Higgs–boson mass and the question of the origin of the electroweak symmetry breaking, seem to require its supersymmetric extension – the MSSM [2] – for a proper resolution. It is well known that MSSM by itself is plagued with a number of problems which were not present in the standard model. In this Letter, we will be concerned with one such problem, viz., the emergence of a plethora of arbitrary CP phases that require severe fine–tuning to explain the smallness of observed CP violation in the Kaon system as well as the non–observation of the electric dipole moment of the neutron [3–5]. This is known as the