Muon (g-2) and XENON1T excess with boosted dark matter in Lμ - Lτ model

Motivated by the growing evidence for lepton flavour universality violation after the first results from Fermilab's muon (g-2) measurement, we revisit one of the most widely studied anomaly free extensions of the standard model namely, gauged L-mu - L-tau model, known to be providing a natural explanation for muon (g - 2). We also incorporate the presence of dark matter (DM) in this model in order to explain the recently reported electron recoil excess by the XENON1T collaboration. We show that the same neutral gauge boson responsible for generating the required muon (g - 2) can also mediate interactions between electron and dark fermions boosted by dark matter annihilation. The required DM annihilation rate into dark fermion require a hybrid setup of thermal and non-thermal mechanisms to generate DM relic density. The tightly constrained parameter space from all requirements remains sensitive to ongoing and near future experiments, keeping the scenario very predictive. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The gauged L-μ-L-τ model, an anomaly free extension of the standard model, provides a natural explanation for muon (g - 2) and can also incorporate dark matter to explain electron recoil excess by the XENON1T collaboration. The interactions between electron and dark fermions are mediated by the same neutral gauge boson responsible for generating muon (g - 2), and hybrid thermal and non-thermal mechanisms are required for dark matter annihilation to generate the relic density. The parameter space is tightly constrained and remains sensitive to ongoing and near future experiments.