Zuckerman Postdoctoral Alumni Scholar Joshua Eby publishes paper on High Energy Physics in ArXiv.
General issues associated with quality and naturalness problems in theories of light QCD-axions, axion-like particles, and relaxions are highlighted. The presence of Planck-suppressed operators generically leads to scalar coupling of axions with the SM. A new class of relaxion models that can address both the QCD relaxion CP problem as well as its quality problem are presented. This new class of models also leads to interesting experimental signatures, which can be searched for at the precision frontier.