SU(3) breaking in hyperon beta decays: A prediction for Xi(0)->Sigma(+)e(nu)over-bar - art. no. 014038.

On the basis of a previous analysis of hyperon semileptonic decay data, a p rediction is presented for g(1)/f(1) in the Xi(0) --> Sigma(+) e(nu)over-ba r beta-decay. The analysis takes into account SU(3) breaking in this sector via the inclusion of mass-driven corrections. A rather precise measurement of the above channel by the KTeV experiment at Fermilab will shortly be av ailable. Since the dependence on the SU(3) parameters, F and D, is identica l to that of the neutron beta-decay, such a measurement will provide a rath er stringent test of SU(3) and the models used to describe its violation in these decays. The prediction given here for the above decay is g(1)/f(1) = 1.17, which leads to a rate of 0.80 X 10(6) s(-1) and thus a branching fra ction of 2.3 x 10(-4). [S0556-2821(99)00701-8].