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# Possible explanation of the electron positron anomaly at 17 MeV in 8Be transitions through a light pseudoscalar

Ellwanger, Ulrich and Moretti, Stefano (2016) Possible explanation of the electron positron anomaly at 17 MeV in 8Be transitions through a light pseudoscalar. Journal of High Energy Physics, 11, [039].

Record type: Article

## Abstract

We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the $^8Be$ anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type quarks are about 0.3 times the coupling of the standard Higgs boson. Then constraints from K and B decays require that loop contributions to flavour changing vertices cancel at least at the 10% level. Constraints from beam dump experiments require the coupling of A to electrons to be larger than about 4 times the coupling of the standard Higgs boson, leading to a short enough A life time consistent with an explanation of the anomaly.

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JHEP11(2016)039 - Version of Record

Accepted/In Press date: 28 October 2016
e-pub ahead of print date: 8 November 2016
Additional Information: 12 pages, discussion of nuclear shell model corrected,
Keywords: hep-ph
Organisations: Theory Group

## Identifiers

Local EPrints ID: 411793
URI: http://eprints.soton.ac.uk/id/eprint/411793
ISSN: 1029-8479
PURE UUID: 2fa976ea-c16f-4813-9783-185c80f82bea

## Catalogue record

Date deposited: 26 Jun 2017 16:30

## Contributors

Author: Ulrich Ellwanger
Author: Stefano Moretti