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

TL;DR

This study uses 2+1 flavor lattice QCD with domain-wall quarks to compute hyperon vector form factors, providing insights into SU(3) symmetry breaking effects in semileptonic decays.

Contribution

It presents the first lattice QCD calculation of hyperon vector form factors for specific semileptonic decays at near-physical quark masses, highlighting the sign of SU(3) breaking corrections.

Findings

Second-order SU(3) breaking correction to f_1(0) is likely negative.

Results obtained at pion mass down to 330 MeV.

Preliminary data suggest negative SU(3) breaking effects.

Abstract

We present results for the hyperon vector form factor f_1 for $\Xi^0 \rightarrow \Sigma^+ l\bar{\nu}$ and $\Sigma^- \rightarrow n l\bar{\nu}$ 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.