New-physics signatures via CP violation in η (′) → π 0 μ + 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 (′) → π 0 μ + 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.

Keywords

• CP Violation
• Semi-Leptonic Decays
• Chiral Lagrangian
• SMEFT