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.
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Escribano, R., Royo, E. & Sanchez-Puertas, P. New-physics signatures via CP violation in η(′) → π0μ+μ− and η′ → ημ+μ− decays. J. High Energ. Phys. 2022, 147 (2022). https://doi.org/10.1007/JHEP05(2022)147