Test of S U(3) Symmetry in Hyperon Semileptonic Decays

Existing analyzes of baryon semileptonic decays indicate the presence of a small S U(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for S U(3) symmetry breaking, one would need a relation similar to the Gell-Mann-Okubo (GMO) baryon mass formula which is satisfied to a few percents, showing evidence for a small S U(3) symmetry breaking effect in the GMO mass formula. In this talk, I would like to present a similar GMO relation obtained in a recent work for hyperon semileptonic decay axial vector current matrix elements. Using these generalized GMO relations for the measured axial vector current to vector current form factor ratios, it is shown that S U(3) symmetry breaking in hyperon semileptonic decays is of 5 - 11% and confirms the validity of the Cabibbo model for hyperon semi-leptonic decays.