Non-unitarity of the leptonic mixing matrix: Present bounds and future sensitivities

Abstract

The non-unitarity of the effective leptonic mixing matrix at low energies is a generic signal of extensions of the Standard Model (SM) with extra fermionic singlet particles, i.e. sterile or right-handed neutrinos, to account for the observed neutrino masses. The low energy effects of such extensions can be described in a model-independent way by the Minimal Unitarity Violation (MUV) scheme, an effective field theory extension of the SM. We perform a global fit of the MUV scheme parameters to the present experimental data, which yields the up-to-date constraints on leptonic non-unitarity. Furthermore, we investigate the sensitivities and discovery prospects of future experiments. In particular, FCC-ee/TLEP would be a powerful probe of flavour-conserving non-unitarity for singlet masses up to ~ 60 TeV. Regarding flavour-violating non-unitarity, future experiments on muon-to-electron conversion in nuclei could even probe extensions with singlet masses up to ~ 0.3 PeV.

29 pages, 5 figures, minor corrections

References in corpus (11)

• The global electroweak fit at NNLO and prospects for the LHC and ILC
• Unitarity of the Leptonic Mixing Matrix
• High Precision determination of the pi, K, D and D_s decay constants from lattice QCD
• Non-Standard Neutrino Interactions with Matter from Physics Beyond the Standard Model
• CP-violation from non-unitary leptonic mixing
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• Probing non-unitary mixing and CP-violation at a Neutrino Factory
• The NuTeV Anomaly, Lepton Universality, and Non-Universal Neutrino-Gauge Couplings
• The NuTeV Anomaly, Neutrino Mixing, and a Heavy Higgs Boson
• Comparison of the Standard Theory Predictions of M_W and Sin^2 theta^lept_eff with their Experimental Values
• Lepton flavour universality test at the CERN NA62 experiment

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