The eta and eta' mesons from lattice QCD

Abstract

Lattice QCD allows a first-principles study of QCD with the freedom to vary the number and masses of the quarks. I present results on the flavour singlet correlations (this illuminates OZI violating effects) for mesons. Concentrating on the pseudoscalar mesons, the flavour singlet mass splitting ($\eta$, ${\eta }^{\prime }$ mass splitting) appears naturally. I also present results on an investigation of decay constants for the $\eta$ and ${\eta }^{\prime }$ ($f_{\eta }$) and discuss which quantities may be accessible in future lattice studies. The Witten-Veneziano approach can also be explored by determining the quenched topological susceptibility on a lattice.

Comments: 13 pages, LATEX, 3 ps figures, Proc. WORKSHOP ON ETA PHYSICS, Uppsala, October 22-27, 2001