Quarkonium correlators and spectral functions at zero and finite temperature from Fermilab action

We study charmonium and bottomonium systems at zero and finite temperatures using Lattice QCD with Fermilab action on anisotropic lattices.Comment: contribution to Hard Probes 200

Non-perturbative Pion Matrix Element of a twist-2 operator from the Lattice

We give a continuum limit value of the lowest moment of a twist-2 operator in pion states from non-perturbative lattice calculations. We find that the non-perturbatively obtained renormalization group invariant matrix element is _{RGI} = 0.179(11), which corresponds to ^{MSbar}(2 GeV) = 0.246(15). In obtaining the renormalization group invariant matrix element, we have controlled important systematic errors that appear in typical lattice simulations, such as non-perturbative renormalization, finite size effects and effects of a non-vanishing lattice spacing. The crucial limitation of our calculation is the use of the quenched approximation. Another question that remains not fully clarified is the chiral extrapolation of the numerical data.Comment: 26 pages, 10 figures, v2: final version, accepted for publication in EPJ