SU(3)--Breaking Effects in Axial--Vector Couplings of Octet Baryons

Present evidence on baryon axial--vector couplings is reviewed, the main emphasis being on internal consistency between asymmetry and rate data. A complete account of all {\sl small} terms in the Standard Model description of these latter leads to {\sl both} consistency {\sl and} evidence for breaking of flavour SU(3) in the axial couplings of octet baryons. Talk presented at "5th Int. Sympos. on Meson--Nucleon Physics and the Structure of the Nucleon", Boulder, CO, sept. 1993. To be published in $\pi N$ Newsletter.