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

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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 ημ+μ process as the most promising channel to find CP-violation at this experimental facility.


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Correspondence to Emilio Royo.

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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).

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  • CP Violation
  • Semi-Leptonic Decays
  • Chiral Lagrangian