Electron magnetic dipole moment

CP violation

Quantum mechanics

Context (archaeology)

Magnetic field

Higgs boson

Gauge (firearms)

Biology

Lepton

Anomalous magnetic dipole moment

Nuclear physics

Particle physics

Archaeology

Neutrino

Standard Model (mathematical formulation)

Magnetic dipole

Anomaly (physics)

Paleontology

Physics

Magnetic moment

Seesaw molecular geometry

Muon

Electron

Physics beyond the Standard Model

History

Physics Reports

We review how the muon anomalous magnetic moment ( null null g null − null 2 null null ) and the quest for lepton flavor violation are intimately correlated. Indeed the decay null null null μ null → null e null γ null null null is induced by the same amplitude for different choices of in- and outgoing leptons. In this work, we try to address some intriguing questions such as: Which hierarchy in the charged lepton sector one should have in order to reconcile possible signals coming simultaneously from null null null g null − null 2 null null null and lepton flavor violation? What can we learn if the null null null g null − null 2 null null null anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is seen in the decay null null null μ null → null e null γ null null null in the foreseeable future? On the other hand, if the null null null μ null → null e null γ null null null decay is seen in the upcoming years, do we need to necessarily observe a signal also in null null null g null − null 2 null null ?. In this attempt, we generally study the correlation between these observables in a detailed analysis of simplified models. We derive master integrals and fully analytical and exact expressions for both phenomena, and address other flavor violating signals. We investigate under which conditions the observations can be made compatible and discuss their implications. Lastly, we discuss in this context several extensions of the SM, such as the Minimal Supersymmetric Standard Model, Left–Right symmetric model, null null null B null null – null null L null null null model, scotogenic model, two Higgs doublet model, Zee–Babu model, 331 model, and null null null null null L null null null μ null null null − null null null L null null null τ null null null null , dark photon, seesaw models type I, II and III, and also address the interplay with null null null μ null → null e null e null e null null null decay and null null null μ null null – null null e null null null conversion.

A call for new physics: The muon anomalous magnetic moment and lepton flavor violation