Hyperon vector form factor from 2+1 flavor lattice QCD
Abstract
We present the first result for the hyperon vector form factor f_1 for Xi^0 -> Sigma^+ l bar{nu} and Sigma^- -> n l bar{nu} semileptonic decays from fully dynamical lattice QCD. The calculations are carried out with gauge configurations generated by the RBC and UKQCD collaborations with (2+1)-flavors of dynamical domain-wall fermions and the Iwasaki gauge action at beta=2.13, corresponding to a cutoff 1/a=1.73 GeV. Our results, which are calculated at the lighter three sea quark masses (the lightest pion mass down to approximately 330 MeV), show that a sign of the second-order correction of SU(3) breaking on the hyperon vector coupling f_1(0) is negative. The tendency of the SU(3) breaking correction observed in this work disagrees with predictions of both the latest baryon chiral perturbation theory result and large N_c analysis.
Cite
@article{arxiv.1209.6115,
title = {Hyperon vector form factor from 2+1 flavor lattice QCD},
author = {Shoichi Sasaki},
journal= {arXiv preprint arXiv:1209.6115},
year = {2012}
}
Comments
7 pages, 12 figures, v2: typos corrected, and references added, v3: version published in PRD