A Call for New Physics : The Muon Anomalous Magnetic Moment and Lepton Flavor Violation

By Manfred Lindner, Moritz Platscher, F. Queiroz. 2016

498 citations recorded by the source corpus.

Abstract We review how the muon anomalous magnetic moment ( g − 2 ) and the quest for lepton flavor violation are intimately correlated. Indeed the decay μ → e γ 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 g − 2 and lepton flavor violation? What can we learn if the g − 2 anomaly is confirmed by the upcoming flagship experiments at FERMILAB and J-PARC, and no signal is seen in the decay μ → e γ in the foreseeable future? On the other hand, if the μ → e γ decay is seen in the upcoming years, do we need to necessarily observe a signal also in g − 2 ? . 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, B – L model, scotogenic model, two Higgs doublet model, Zee–Babu model, 331 model, and L μ − L τ , dark photon, seesaw models type I, II and III, and also address the interplay with μ → e e e decay and μ – e conversion.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/377dad39e27ebc62b2b056e170074dad5eedf0e3

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In Nuclear and High Energy Physics

Citations in the corpus

Charged Lepton Flavour Violation: An Experimental and Theoretical Introduction (2017, background): “in the recent review [28] – (g − 2)μ is an observable closely related to CLFV processes: it is induced by the flavour-conserving counterpart of the dipole operator that would be responsible for decays of the type `i → `jγ (cf.”
Flavor structures of charged fermions and massive neutrinos (2019, methodology): “If one goes beyond the SM framework by incorporating the seesaw scenarios with some supersymmetric theories, for example, it will certainly be possible to achieve much richer phenomenology of lepton flavor violation in the charged-lepton sector [569, 583, 586, 587, 588, 589, 590, 591, 592, 593, 594,”
From the Trees to the Forest: A Review of Radiative Neutrino Mass Models (2017, methodology): “We refer to the recent review [506] for a guide regarding new physics contributions to the muon AMM.”