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arXiv · 2011.04725

The see-saw portal at future Higgs Factories

Daniele Barducci·Enrico Bertuzzo·Andrea Caputo·Pilar Hernandez·Barbara Mele
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Abstract

We consider an extension of the Standard Model with two right-handed singlet fermions with mass at the electroweak scale that induce neutrino masses, plus a generic new physics sector at a higher scale $\Lambda$. We focus on the effective operators of lowest dimension $d=5$, which induce new production and decay modes for the singlet fermions. We assess the sensitivity of future Higgs Factories, such as FCC-ee, CLIC-380, ILC and CEPC, to the coefficients of these operators for various center of mass energies. We show that future lepton colliders can test the cut-off of the theory up to $\Lambda \simeq 500 - 1000\;$TeV, surpassing the reach of future indirect measurements of the Higgs and $Z$ boson widths. We also comment on the possibility of determining the underlying model flavor structure should a New Physics signal be observed, and on the impact of higher dimensional $d=6$ operators on the experimental signatures.

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Daniele Barducci, Enrico Bertuzzo, Andrea Caputo, Pilar Hernandez, Barbara Mele. 2020-11-09. The see-saw portal at future Higgs Factories. https://doi.org/10.1007/jhep03(2021)117

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