Nonabelian Berry Phases in Baryons

Abstract

We show how generic nonabelian gauge fields can be induced in baryons when a hierarchy of fast degrees of freedom is integrated out. We identify them with nonabelian Berry potentials and discuss their role in transmuting quantum numbers in bag and soliton models of baryons. The resulting baryonic spectra both for light and heavy quark systems are generic and resemble closely the excitation spectrum of diatomic molecules. The symmetry restoration in the system, i.e., the electronic rotational invariance in diatomic molecules, the heavy-quark symmetry in heavy baryons, etc., is interpreted in terms of the vanishing of nonabelian Berry potentials that otherwise govern the hyperfine splitting.