Empirical Relations Involving the Hyperons and Baryon Isobars

Abstract

A scheme for the classification of the nucleon isobars recently proposed by Kycia and Riley is extended to include the hyperon isobars ${Y_0}^{*}$ and ${Y_1}^{*}$ with strangeness $S=-1\mathrm{}$. The present model is essentially based on the existence of empirical mass relations involving the various baryon isobar states. The extent of the validity of these mass relations is discussed. A classification of the six isobar systems which occur in the present scheme is described. We also discuss the set of quantum numbers which is necessary to characterize an isobaric state.