Extraction of the CKM matrix element Vus from the hyperon semileptonic decays

The chiral constituent quark model with configuration mixing (χCQMconfig), which is successful in explaining the weak vector and axial-vector form factors for the strangeness-changing as well as strangeness-nonchanging hyperon semileptonic decays at Q2=0, has been extended to determine the CKM matrix element Vus for the strangeness-changing decays. The implications of the effect of the SU(3) symmetry breaking, Q2-dependence and radiative corrections on the form factors and Vus have also been investigated. It is found that the results with SU(3) symmetry breaking show considerable improvement over the SU(3) symmetric results when compared with the existing experimental data. The inclusion of the Q2-dependence and radiative corrections in form factors have only a small effect on the prediction of Vus as is expected from the theory. (orig.)