Pole Model of Nonleptonic Hyperon Decays, and Model of Hadrons and Their Fundamental Weak Interaction

Abstract

The pole model of nonleptonic hyperon decays proposed by Kawasaki, Imoto and Furui (KIF) and Lee and Swift is reexamined for the purpose of establishing connection between the phenomenology and subnuclear structure of hadrons and their weak interaction. It is assumed that there exist three urbaryons which play an essential role in composing hadrons. Baryons are assumed to be nonrelativistic bound states of such three urbaryons. Two types of hyperon models are considered: One is the quartet-like model (ModelI), and the other is the quark-like model (ModelII). The effective two-body weak Hamiltonian between baryons becomes parity-conserving, and in a simplified limit in which all strong interaction corrections are neglected this Hamiltonian is of the D or F type for ModelI or II, respectively. In general, matrix elements of nonleptonic hyperon decays are written by using effectively five parameters. η (or η′), a member of the parameters, is introduced which is regarded as a measure of departure from the simplified limit. For any value of η (or η′), one can reproduce all the experimental data on nonleptonic hyperon decays including decay probabilities. This is possible only when the F/Dratio (a member of the five parameters) of the strong baryon-pseudoscalar-meson interaction is equal to ~ (0.5 ~ 0.6). Consistency of the values of adjusted parameters with other phenomena is investigated. It is concluded that to regard the weak Jp·Jp+ interaction as the only fundamental interaction responsible for nonleptonic decays is unlikely, where Jp stands for an appropriate urbaryonic or Cabibbo-like current. It seems difficult at present to determine which of the two Models is superior owing especially to the lack of knowledge of the parity-nonconserving amplitude.