UC Santa Cruz
Constraining axionlike particles from rare pion decays
- Author(s): Altmannshofer, W
- Gori, S
- Robinson, DJ
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevD.101.075002
© 2020 authors. Published by the American Physical Society. Ultraviolet completions for axionlike particles (ALPs) lighter than the neutral pion generically induce ALP-neutral pion mixing and are therefore sensitive to direct constraints on the mixing angle. For ALPs below the pion mass, we demonstrate that strong and novel bounds on the ALP-pion mixing angle can be extracted from existing rare pion decay data, measured by the PIENU and PIBETA experiments.