Properties of light scalar mesons from lattice QCD

Abstract

Lattice QCD with ${N}_{f}=2$ flavors of sea quark is used to explore the spectrum and decay of scalar mesons. We are able to determine the ${b}_{1}\ensuremath{-}{a}_{0}$ mass difference and this leads to the conclusion that the lightest nonsinglet scalar meson (${a}_{0}$) has a mass of 1.01(4) GeV. We determine from the lattice the coupling strength to KK and $\ensuremath{\pi}\ensuremath{\eta}$. We compute the leptonic decay constant of the lightest nonsinglet scalar meson. We discuss the impact of these lattice results on the interpretation of the ${a}_{0}(980)$ state. We also discuss ${K}_{0}^{*}$ states.