R. Floresmendieta et al., DETERMINATION OF THE KOBAYASHI-MASKAWA-CABIBBO MATRIX ELEMENT V-US UNDER VARIOUS FLAVOR-SYMMETRY-BREAKING MODELS IN HYPERON SEMILEPTONIC DECAYS, Physical review. D. Particles and fields, 54(11), 1996, pp. 6855-6860
We study the success to describe hyperon semileptonic decays of four m
odels that incorporate second-order SU(3) symmetry-breaking correction
s. The criteria to assess their success is by determining V-us in each
of the three relevant hyperon semileptonic decays and comparing the v
alues so obtained with one another and also with the one that comes fr
om K-l3 decays. A strong dependence on the particular symmetry-breakin
g model is observed. Values of V-us which do not agree with the one of
K-l3 are generally obtained. However, in the context of chiral pertur
bation theory, only the model whose corrections are O(m(s)) and O(m(s)
(3/2)) is successful. Using its predictions for the f(1) form factors
one can quote a value of V-us from this model, namely, V-us = 0.2176+/
-0.0026, which is in excellent agreement with the K-l3 one.