Hyperon vector coupling f_1(0) from 2+1 flavor lattice QCD

Abstract

We present results for the hyperon vector form factor f_1 for ${\Xi }^0\to {\Sigma }^{+}l\bar{\nu }$ and ${\Sigma }^{-}\to nl\bar{\nu }$ semileptonic decays from dynamical lattice QCD with domain-wall quarks. Simulations are performed on the 2+1 flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice cutoff of 1/a = 1.7 GeV. Our preliminary results, which are calculated at the lightest sea quark mass (pion mass down to approximately 330 MeV), show that a sign of the second-order correction of SU(3) breaking on hyperon vector coupling f_1(0) is likely negative.

Comments: 4 pages, 2 figures, talk given at International Conference on the Structure of Baryons (BARYONS'10), Osaka, Japan, Dec. 7-11, 2010