Pion decay constraints on exotic 17 MeV vector bosons

Matheus Hostert, Maxim Pospelov

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We derive constraints on the couplings of light vector particles to all first-generation Standard Model fermions using leptonic decays of the charged pion, π+→e+νeXμ. In models where the net charge to which Xμ couples to is not conserved, no lepton helicity flip is required for the decay to happen, enhancing the decay rate by factors of O(mπ4/me2mX2). A past search at the SINDRUM-I spectrometer severely constrains this possibility. In the context of the hypothesized 17 MeV particle proposed to explain anomalous Be8, He4, and C12 nuclear transitions claimed by the ATOMKI experiment, this limit rules out vector-boson explanations and poses strong limits on axial-vector ones.

Original languageEnglish (US)
Article number055011
JournalPhysical Review D
Issue number5
StatePublished - Sep 1 2023
Externally publishedYes

Bibliographical note

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© 2023 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.


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