Parity Doubles in Quark Physics

Abstract

There are numerous examples of very nearly degenerate states of opposite parity in molecular physics. The ammonia maser is based on one such double. Theory shows that these parity doubles can occur if the nuclear shape in the molecule is reflection-asymmetric because the time scales of the shape and the electronic cloud are well-separated. Parity doubles occur in nuclear physics as well for odd $A\sim 219-229$. We discuss the theoretical foundation of these doubles and on that basis suggest that parity doubles should occur in particle physics too. In particular they should occur among baryons composed of $cbu$ and $cbd$ quarks.

Comments: minor changes made; to appear in Phys.Rev.Lett