Quark mass uncertainties revive Kim–Shifman–Vainshtein–Zakharov axion dark matter

Matthew R Buckley, Hitoshi Murayama
2007 Journal of Cosmology and Astroparticle Physics  
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 $2-3 \mu$eV mass range composing 100% of the galactic dark matter halo can evade the experimental limits placed by the ADMX collaboration.
doi:10.1088/1475-7516/2007/07/012 fatcat:566trhg6vnawbb7ptzspkvnshy