Naturalness of the relaxion mechanism


The relaxion mechanism is a novel solution to the hierarchy problem that utilizes the dynamics of an axion-like field. I discuss results from the first statistical analysis of the relaxion mechanism, in which we quantified the relative plausibility of a QCD and a non-QCD relaxion model versus the Standard Model with Bayesian statistics, which includes an automatic penalty for fine-tuning. We included experimental constraints upon the weak-scale, $\theta_\mathrm{QCD}$ and inflationary observables measured by Planck/BICEP. Whilst we confirmed that relaxion models could solve the hierarchy problem, we found that their unconventional cosmology demolishes their plausibility.

Sydney University
Andrew Fowlie
Junior Faculty

My research interests include particle physics and statistics.