Eta und Eta' Mesons from Lattice QCD
Carsten Urbach (HISKP Bonn)

We determine mass and mixing angles of \(\eta\) and \(\eta'\) states using \(N_f=2+1+1\) Wilson twisted mass lattice QCD. We describe how those flavour singlet states need to be treated in this lattice formulation. Results are presented for three values of the lattice spacing and a wide range of pion mass values. We discuss continuum and chiral extrapolation and improved ways to determine \(\eta\) and \(\eta'\) meson masses.