Nearly-Degenerate Opposite-Parity Levels in Atomic Dysprosium: A Novel System for the Study of Parity Non-Conservation

There exists in atomic dysprosium a pair of nearly-degenerate levels of opposite parity. These levels are of potential interest for the study of parity non-conservation because the small energy separation enhances level mixing due to weak-interaction processes. In this paper, we review the unique properties of these levels which make them attractive for measurements of parity non-conservation, and outline the principle of such an experiment now underway.