Chiral Dynamics of Octet Baryons and Nonleptonic Decays of Hyperons

Chiral dynamics of the octet baryons is discussed, and a phenomenological chiral-invariant Lagrangian is derived. It is noted that in a chiral-invariant Lagrangian for the octet baryons, the structure of the axial-vector currents and the pattern of baryon-meson couplings are uniquely characterized by two free parameters, corresponding to $\frac{G_A}{G_V}$ and the $\frac{D}{F}$ ratio of the axial-vector currents. Nonleptonic hyperon decays are discussed from the chiral-dynamics point of view. A discussion is given on the transformation properties of the nonleptonic weak interactions under chiral transformations. Conditions under which the usual current-algebra analyses are valid are elaborated.