η and η decays into lepton pairs

  • Pere Masjuan
  • Pablo Sanchez-PuertasEmail author
Open Access
Regular Article - Theoretical Physics


In this work, we calculate the branching ratios for the \( \eta \left(\eta^{\prime}\right)\to \overline{\ell}\ell \) decays, where = e,μ. These processes have tiny rates in the Standard Model due to spin flip, loop and electromagnetic suppressions, which could make them sensitive to New Physics effects. In order to provide a reliable input for the Standard Model, we exploit the general analytical properties of the amplitude. For that purpose, we invoke the machinery of Canterbury approximants, which provides a systematic description of the underlying hadronic physics in a data-driven fashion. Given the current experimental discrepancies, we discuss in detail the role of the resonant region and comment on the reliability of χPT calculations. Finally, we discuss the kind of new physics which we think would be relevant to account for them.


Phenomenological Models QCD Phenomenology 


Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.


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Authors and Affiliations

  1. 1.PRISMA Cluster of Excellence and Institut für KernphysikJohannes Gutenberg-UniversitätMainzGermany

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