Dark Sector as Origin of Light Lepton Mass and Its Phenomenology

TL;DR

This paper proposes a dark sector model explaining small lepton masses via one-loop effects, addressing the muon g-2 anomaly, neutrino oscillations, and providing testable predictions for future colliders.

Contribution

It introduces a novel dark sector framework that naturally accounts for lepton mass smallness and anomalies, with specific phenomenological implications and experimental testability.

Findings

Model explains muon g-2 anomaly and neutrino oscillations.

Dark scalar and fermionic dark matter scenarios analyzed.

Predictions for collider tests and lepton Yukawa coupling measurements.

Abstract

We discuss a model with a dark sector, in which smallness of mass for charged leptons and neutrinos can naturally be explained by one-loop effects mediated by particles in the dark sector. These new particles, including dark matter candidates, also contribute to the anomalous magnetic dipole moment, denoted by $(g-2)$, for charged leptons. We show that our model can explain the muon $(g-2)$ anomaly and observed neutrino oscillations under the constraints from lepton flavor violating decays of charged leptons. We illustrate that the scenario with scalar dark matter is highly constrained by direct searches at the LHC, while that with fermionic dark matter allows for considering dark scalars with masses of order 100 GeV. Our scenario can be tested by a precise measurement of the muon Yukawa coupling as well as the direct production of dark scalar bosons at future electron-positron colliders.