Neutrino masses, leptonic flavor mixing, and muon (g-2) in the seesaw model with the U(1)Lμ-Lτ gauge symmetry

The latest measurements of the anomalous muon magnetic moment a(mu) (g(mu) - 2)/2 show a 4.2 sigma discrepancy between the theoretical prediction of the Standard Model and the experimental observations. To account for such a discrepancy, we consider a possible extension of the type-(I+II) seesaw model for neutrino mass generation with a gauged L-mu - L-tau symmetry. By explicitly constructing an economical model with only one extra scalar singlet, we demonstrate that the gauge symmetry U(1)(L mu-L tau) and its spontaneous breaking are crucial not only for explaining the muon (g - 2) result but also for generating the neutrino masses and leptonic flavor mixing. Various phenomenological implications and experimental constraints on the model parameters are also discussed.

Automated summary

The latest measurements reveal a significant discrepancy between the theoretical prediction of the Standard Model and experimental observations. By extending the seesaw model and introducing an additional scalar singlet, the gauged L-μ-L-τ symmetry is shown to be crucial for explaining the discrepancy and generating neutrino masses and leptonic flavor mixing.