Seminar: ‘Beyond the Minimal Axion: Robustness of Standard Predictions’

Title: ‘Beyond the Minimal Axion: Robustness of Standard Predictions’

Speaker: Sung Mook Lee (CERN)

Venue & Time: Red Room / 15:00

Abstract: The QCD axion is one of the most compelling candidates for physics beyond the Standard Model, as it can simultaneously solve the strong CP problem and account for the dark matter abundance. In the minimal single-axion framework, especially in a post-inflationary cosmology, the combination of axion gauge coupling quantization and axion production from string networks leads to sharp and highly predictive targets. In this talk, we revisit these predictions in a simple but realistic setup with an additional confining dark gauge group and extra axion degrees of freedom. We will show how axion mixing and defect dynamics can modify both the coupling predictions and the relic abundance expectations through emergent features specific to multi axion scenarios, and discuss when the standard single axion benchmarks remain reliable. This provides a useful test of what remains truly robust in extended axion theories and helps guide current experimental targets.