Muon g-2 Anomaly and Dark Leptonic Gauge Boson

Understand

One of the major motivations to search for a dark gauge boson of MeV-GeV scale is the long-standing muon g-2 anomaly.

• Because of active searches such as fixed target experiments and rare meson decays, the muon g-2 favored parameter region has been rapidly reduced.
• With the most recent data, it is practically excluded now in the popular dark photon model.
• We overview the issue and investigate a potentially alternative model based on the gauged lepton number or U(1)_L.