Supersizing axions with small size instantons

We construct a new framework to calculate the enhancement of axion masses and concomitant effects on axion-meson mixing arising from small size instantons (SSTs), which originate in models featuring an extended color gauge symmetry. The framework is based on an explicit evaluation of 't Hooft determinantal operators that partition into instanton amplitudes, affording a more precise determination of the axion-diphoton coupling than previous results. Using an explicit model first presented in ref. [1], we demonstrate that axions solving the strong CP problem can have electroweak scale masses and higher, driven by SSI effects. Such collider axions are prime targets for resonance searches at the Large Hadron Collider and afford a unique anchor for motivating extended color symmetries.

Automated summary

In this study, a new framework is constructed to calculate the enhancement of axion masses and the effects of axion-meson mixing caused by small size instantons. By using a specific model, it is demonstrated that axions can have masses at the electroweak scale, which is important for resonance searches and the development of extended color symmetries.