The Kaplan-Manohar ambiguity in light quark masses allows for a larger uncertainty in the ratio of up to down quark masses than naive estimates from the chiral Lagrangian would indicate. We show that it allows for a relaxation of experimental bounds on the QCD axion, specifically KSVZ axions in the 2−3μeV mass range composing 100% of the galactic dark matter halo can evade the experimental limits placed by the ADMX collaboration.
@article{arxiv.0705.0542,
title = {Quark mass uncertainties revive KSVZ axion dark matter},
author = {M. R. Buckley and H. Murayama},
journal= {arXiv preprint arXiv:0705.0542},
year = {2011}
}