Properties of light scalar mesons from lattice QCD

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 $b_1-a_0$ 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 $\pi \eta$. 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.