CHIRAL SYMMETRY AND WEAK DECAY OF HYPERNUCLEI

Abstract

The weak decays of hyperons and hypernuclei are studied from the chiral symmetry viewpoint. The soft pion relations are useful in understanding the isospin properties of the weak hyperon decays. Recent development on the short-range part of the $\Lam N\to NN$ weak transitions shows fairly good account of the weak decays of hypernuclei, though it fails to explain the $n/p$ ratio. The $\pip$ decays of light hypernuclei are studied in the soft pion approach. They are related to the $\DI=3/2$ amplitudes of the nonmesonic decay.