Probing the muon $g_\mu-2$ anomaly, $L_{\mu} - L_{\tau}$ gauge boson and Dark Matter in dark photon experiments

摘要: Abstract In the L μ − τ model 3.6 σ discrepancy between predicted and measured values of anomalous magnetic moment positive muons can be explained by existence a new dark boson Z ′ with mass in sub-GeV range, which is coupled at tree level predominantly to second third lepton generations. However, one-loop coupling electrons or quarks induced via γ kinetic mixing, generated through loop involving muon tau lepton. This loophole has important experimental consequences since it opens up possibilities for complementary searches high-energy electron beams, particular ongoing NA64 incoming photon experiments. An extension able explain relic Dark Matter density also discussed.