New-physics signatures via CP violation in η(′) → π0μ+μ− and η′ → ημ+μ− decays

Abstract

Abstract In this work we investigate the prospect of observing new-physics signatures via CP violation in η(′) → π0μ+μ− and η′ → ημ+μ− decays at the REDTOP experiment. We make use of the SMEFT to parametrise the new-physics CP-violating effects and find that the projected REDTOP statistics are not competitive with respect to nEDM experiments. This reasserts the η → μ+μ− process as the most promising channel to find CP-violation at this experimental facility.