Left-handed nuclei

Abstract

The orientation of the angular momentum vector with respect to the triaxial density distribution selects a left-handed or right-handed system principal axes. This breaking of chiral symmetry manifests itself as pairs of nearly identical $\Delta I=1$-bands. The chiral structures combine high-j particles and high-j holes with a triaxial rotor. Tilted axis cranking calculations predict the existence of such configurations in different mass regions. There is experimental evidence in odd-odd nuclei around mass 134. The quantized motion of the angular momentum vector between the left- and right-handed configurations, which causes the splitting between the chiral sister bands, can be classified as tunneling (chiral rotors) or oscillation (chiral vibrators).

Invited lecture at the Conference on Frontiers of Nuclear Structure, Berkeley, 2002