The U_A(1) Problem on the Lattice with Ginsparg-Wilson Fermions
High Energy Physics - Lattice
2009-11-07 v2 High Energy Physics - Phenomenology
High Energy Physics - Theory
Abstract
We show how it is possible to give a precise and unambiguous implementation of the Witten--Veneziano formula for the eta' mass on the lattice, which looks like the formal continuum one, if the expression of the topological charge density operator, suggested by fermions obeying the Ginsparg--Wilson relation, is employed. By using recent numerical results from simulations with overlap fermions in 2 (abelian Schwinger model) and 4 (QCD) dimensions, one obtains values for the mass of the lightest pseudo-scalar flavour-singlet state that agree within errors with theoretical expectations and experimental data, respectively.
Cite
@article{arxiv.hep-lat/0108009,
title = {The U_A(1) Problem on the Lattice with Ginsparg-Wilson Fermions},
author = {L. Giusti and G. C. Rossi and M. Testa and G. Veneziano},
journal= {arXiv preprint arXiv:hep-lat/0108009},
year = {2009}
}
Comments
Expanded discussion in section three and in the conclusions