The SU(3) topological susceptibility at zero and finite temperature: A lattice Monte Carlo evaluation

Abstract

We extend previous calculations of the zero-temperature topological susceptibility, χ t, to larger lattices (up to 20 4) and smaller lattice spacings (up to β=6.2). Using a new technique we are able to achieve a precise control of finite size corrections. We confirm, with much greater systematic and statistical precision, that the dimensionless ratio χ t/ K 2 is independent of β for β⩾5.7. This enables us to extract χ t in physical units and we find χ t =(179±4 MeV) 4 - statistical error only - which is in striking agreement with the Witten-Veneziano calculation. We also investigate the previously observed fact that χ t is suppressed as the temperature is raised through the deconfining transition. We find that χ t is in fact discontinuous at the phase transition and that its temperature dependence is otherwise weak as long as it remains in a single well-defined phase.