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arXiv · 2210.02461

Long-lived heavy neutral leptons from mesons in effective field theory

Rebeca Beltrán·Giovanna Cottin·Juan Carlos Helo·Martin Hirsch·Arsenii Titov·Zeren Simon Wang
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Abstract

In the framework of the low-energy effective field theory of the Standard Model extended with heavy neutral leptons (HNLs), we calculate the production rates of HNLs from meson decays triggered by dimension-six operators. We consider both lepton-number-conserving and lepton-number-violating four-fermion operators involving either a pair of HNLs or a single HNL. Assuming that HNLs are long-lived, we perform simulations and investigate the reach of the proposed far detectors at the high-luminosity LHC to (i) active-heavy neutrino mixing and (ii) the Wilson coefficients associated with the effective operators, for HNL masses below the mass of the $B$-meson. We further convert the latter to the associated new-physics scales. Our results show that scales in excess of hundreds of TeV and the active-heavy mixing squared as small as $10^{-15}$ can be probed by these experiments.

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Rebeca Beltrán, Giovanna Cottin, Juan Carlos Helo, Martin Hirsch, Arsenii Titov, Zeren Simon Wang. 2022-11-28. Long-lived heavy neutral leptons from mesons in effective field theory. https://doi.org/10.1007/jhep01(2023)015

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