Flavour alignment of New Physics in light of the $(g-2{)}_{\mu }$ anomaly

Abstract

We investigate the flavour alignment conditions that New Physics (NP) models need to satisfy in order to address the $(g-2{)}_{\mu }$ anomaly and, at the same time, be consistent with the tight bounds from $\mu \to e\gamma$ and $\tau \to \mu \gamma$. We analyse the problem in general terms within the SMEFT, considering the renormalisation group evolution of all the operators involved. We show that semileptonic four-fermion operators, which are likely to generate a sizeable contribution to the $(g-2{)}_{\mu }$ anomaly, need to be tightly aligned to the lepton Yukawa couplings and the dipole operators in flavour space. While this tuning can be achieved in specific NP constructions, employing particular dynamical assumptions and/or flavour symmetry hypotheses, it is problematic in a wide class of models with broken flavour symmetries, such as those proposed to address both charged- and neutral-current $B$ anomalies. We quantify this tension both in general terms, and in the context of explicit NP constructions.

References in corpus (21)

• The $g-2$ of charged leptons, $\alpha (M_Z^2)$ and the hyperfine splitting of muonium
• Contributions of axion-like particles to lepton dipole moments
• Reading the footprints of the B-meson flavor anomalies
• With or without U(2)? Probing non-standard flavor and helicity structures in semileptonic B decays
• Effective field theory interpretation of lepton magnetic and electric dipole moments
• A Model of Muon Anomalies
• Muon $g-2$ and $B$-anomalies from Dark Matter
• A Minimal Explanation of Flavour Anomalies: B-Meson Decays, Muon Magnetic Moment, and the Cabibbo Angle
• Challenges for an axion explanation of the muon $g-2$ measurement
• The Tiny (g-2) Muon Wobble from Small-$\mu$ Supersymmetry
• FCNC decays of SM fermions into a dark photon
• Leptoquark Option for $B$-meson Anomalies and Leptonic Signatures
• Interplay of New Physics Effects in $(g-2{)}_{\ell }$ and $h\to {\ell }^{+}{\ell }^{-}$ -- Lessons from SMEFT
• Anomalous $Z^{\prime }$ bosons for anomalous $B$ decays
• Universal Scalar Leptoquark Action for Matching
• Explaining $(g-2{)}_{\mu }$ with Multi-TeV Sleptons
• What is the scale of new physics behind the muon $g-2$?
• Semi-secretly interacting ALP as an explanation of Fermilab muon $g-2$ measurement
• Radiative lepton mass and muon $g-2$ with suppressed lepton flavor and CP violations
• A view of flavour physics in 2021
• Naturalness of lepton non-universality and muon g-2

Cited by in corpus (8)

• The Standard Model effective field theory at work
• Adding Flavor to the SMEFT
• On $(g-2{)}_{\mu }$ From Gauged $\mathrm{U}(1{)}_X$
• Indirect constraints on lepton-flavour-violating quarkonium decays
• The Muon Magnetic Moment and Physics Beyond the Standard Model
• Froggatt-Nielsen Meets the SMEFT
• Correlating $0\nu \beta \beta$ decays and flavor observables in leptoquark models
• Explaining lepton-flavor non-universality and self-interacting dark matter with $L_{\mu }-L_{\tau }$