We perform an eta' mass analysis based on a total of 1130 dynamical gauge field configurations, with 5 different quark mass values on lattices of size 16^3*32 (SESAM) and 24^3*40 (TkL) at beta = 5.6. We employ the stochastic estimator technique and spectral methods to deal with the disconnected piece of the flavour singlet correlation function. We demonstrate that very early plateau formation in the local eta' mass can be achieved by first ground state projecting the connected piece of its correlator.
@article{arxiv.hep-lat/0110077,
title = {A New Approach to eta' on the Lattice},
author = {K. Schilling and H. Neff and N. Eicker and Th. Lippert and J. W. Negele},
journal= {arXiv preprint arXiv:hep-lat/0110077},
year = {2008}
}