Abstract
We discuss sensitivities to lepton flavor violating (and conserving) interactions at future muon colliders, especially at μ+μ+ colliders. Compared with the searches for rare decays of μ and τ, we find that the TeV-scale future colliders have better sensitivities depending on the pattern of hierarchy in the flavor mixings. As an example, we study the case with the type-II seesaw model, where the flavor mixing parameters have direct relation to the neutrino mass matrix. At a μ+μ+ collider, the number of events of the μ+μ+ → μ+τ+ process can be larger than \( \mathcal{O}(100) \) with the center of mass energy \( \sqrt{s} \) = 2 TeV, and with an integrated luminosity \( \mathcal{L} \) = 1 ab−1, while satisfying bounds from rare decays of μ and τ. We discuss impacts of the overall mass scale of neutrinos as well as CP violating phases to the number of expected events.
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Acknowledgments
The work is supported by JSPS KAKENHI Grant Numbers JP19H00689 (RK), JP21H01086 (KF, RK), JP22K21350 (KF, RK), and MEXT KAKENHI Grant Number JP18H05542 (RK).
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Fridell, K., Kitano, R. & Takai, R. Lepton flavor physics at μ+μ+ colliders. J. High Energ. Phys. 2023, 86 (2023). https://doi.org/10.1007/JHEP06(2023)086
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DOI: https://doi.org/10.1007/JHEP06(2023)086