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In this talk, we will discuss the impact of introducing a heavy vector-like fermion as a fourth generation to the Standard Model (SM) fermion sector. This new particle can modify the scattering amplitude of a specific meson-antimeson (Bs) mixing process through radiative corrections. Such a fermion is often proposed in various Beyond the Standard Model (BSM) scenarios to address some of the major open questions in particle physics, like the origin of the non-trivial breaking patterns of the accidental global flavor symmetry, the electroweak hierarchy problem, and under additional constraints, it could also be a dark matter candidate. We will show how, in a Pati-Salam-like extension of the SM, this particle can generate the SM flavor mixings and masses as an effective interaction, while also inducing new neutral and right-handed currents at higher scales. Through an explicit loop calculation, we were able to derive a lower bound on its mass, by ruling out parameter space regions that are incompatible with experimental data, which turned out to be located around 1 TeV.

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Sarina Michael, ETH Zürich
Seminar Room 0.01, ETP
Contact: Dmitry Bagrets