Looking forward to Lepton-flavor-violating ALPs

Abstract

We assess the status of past and future experiments on lepton flavor violating (LFV) muon and tau decays into a light, invisible, axion-like particle (ALP), $a$. We propose a new experimental setup for MEG II, the MEGII-fwd, with a forward calorimeter placed downstream from the muon stopping target. Searching for $\mu \to ea$ decays MEGII-fwd is maximally sensitive to LFV ALPs, if these have nonzero couplings to right-handed leptons. The experimental set-up suppresses the (left-handed) Standard Model background in the forward direction by controlling the polarization purity of the muon beam. The reach of MEGII-fwd is compared with the present constraints, the reach of Mu3e and the Belle-II reach from $\tau \to \ell a$ decays. We show that a dedicated experimental campaign for LFV muon decays into ALPs at MEG II and Mu3e will be able to probe the ALP parameter space in an unexplored region well beyond the existing astrophysical constraints. We study the implications of these searches for representative LFV ALP models, where the presence of a light ALP is motivated by neutrino masses, the strong CP problem and/or the SM flavor puzzle. To this extent we discuss the majoron in low-scale seesaw setups and introduce the LFV QCD axion, the LFV axiflavon and the leptonic familon, paying particular attention to the cases where the LFV ALPs constitute cold dark matter.

62 pages, 13 figures, 4 tables, fixed broken reference, matching published version

References in corpus (34)

• The landscape of QCD axion models
• Right-Handed Neutrinos at LHC and the Mechanism of Neutrino Mass Generation
• Collider Probes of Axion-Like Particles
• Dielectric Haloscopes: A New Way to Detect Axion Dark Matter
• Low energy effects of neutrino masses
• Minimal Flavour Seesaw Models
• Flaxion: a minimal extension to solve puzzles in the standard model
• Redefining the Axion Window
• Quark Flavor Phenomenology of the QCD Axion
• Stellar Recipes for Axion Hunters
• Revisiting the axion bounds from the Galactic white dwarf luminosity function
• A New Flavor of Searches for Axion-Like Particles
• Axion search with a quantum-limited ferromagnetic haloscope
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• Low Energy Signatures of the TeV Scale See-Saw Mechanism
• Supernova Muons: New Constraints on Z' Bosons, Axions, and ALPs
• Muons in supernovae: implications for the axion-muon coupling
• Limits on Axion Couplings from the first 80-day data of PandaX-II Experiment
• High angular resolution ALMA images of dust and molecules in the SN 1987A ejecta
• A search for two body muon decay signals
• Future Directions in the Microwave Cavity Search for Dark Matter Axions
• Exploring New Physics with O(keV) Electron Recoils in Direct Detection Experiments
• Detectability of Axion Dark Matter with Phonon Polaritons and Magnons
• NS 1987A in SN 1987A
• Search for the light dark matter with an X-ray spectrometer
• Probing $e\mu$ flavor-violating ALP at Belle II
• Minimal Flavor Violation with Axion-like Particles
• Determining the Neutrino Lifetime from Cosmology
• Lepton Flavor Violation with Displaced Vertices
• Muonium-antimuonium oscillations in effective field theory
• A Bayesian comparison of U(1) lepton flavour models
• Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment
• Naturalness, b to s gamma, and SUSY Heavy Higgses
• Model identification in ${\mu }^{-}\to e^{-}$ conversion with invisible boson emission using muonic atoms

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• Gravitational Waves and Dark Photon Dark Matter from Axion Rotations
• Strong supernovae bounds on ALPs from quantum loops
• Supernova bound on Axion-Like Particles coupled with electrons
• Stellar Evolution confronts Axion Models
• Lepton-flavor violating axions at MEG II
• Cosmological Implications of Axion-Matter Couplings
• Unleashing the full power of LHCb to probe Stealth New Physics
• Flavor Violating Axions in the Early Universe
• Lepton-Flavor-Violating ALPs at the Electron-Ion Collider: A Golden Opportunity
• Hunting for CP-violating axionlike particle interactions
• Detecting an axion-like particle with machine learning at the LHC
• Searching for the axion-like particle at the EIC
• Models of the Muonium to Antimuonium Transition
• Axion Dark Matter from Lepton flavor-violating Decays
• The Anomalous Case of Axion EFTs and Massive Chiral Gauge Fields
• Naturally astrophobic QCD axion
• Science Case for the new High-Intensity Muon Beams HIMB at PSI
• Search for Lepton-Flavor-Violating $\tau$ Decays to a Lepton and an Invisible Boson at Belle II
• Probing $\mu e\gamma \gamma$ contact interactions with $\mu \to e$ conversion
• Search for Majoron at the COMET Experiment
• Testing axion couplings to leptons in $Z$ decays at future $e^{+}{e}^{-}$ colliders
• Leptoflavorgenesis: baryon asymmetry of the Universe from lepton flavor violation
• Search for lepton-flavor-violating ALPs at a future muon collider and utilization of polarization-induced effects
• Dark matter in the Scotogenic model with spontaneous lepton number violation
• $\tau \to \ell +$ invisible through invisible-savvy collider variables
• Observable flavor violation from spontaneous lepton number breaking
• Flavor violating muon decay into an electron and a light gauge boson
• Lepton Phenomenology of Stueckelberg Portal to Dark Sector
• Probing a light dark sector at future lepton colliders via invisible decays of the SM-like and dark Higgs bosons
• High-precision muon decay predictions for ALP searches
• Tera-Zooming in on light (composite) axion-like particles
• Anomaly-free axion dark matter in three Higgs doublet model and its phenomenological implications
• Search for Lepton Flavor Violating Decay at FASER
• Flavor-changing light bosons with accidental longevity
• Anomaly-free ALP from non-Abelian flavor symmetry
• Probing an intrinsically flavorful ALP via tau-lepton flavor physics
• Electron Beam Dump Constraints on Light Bosons with Lepton Flavor Violating Couplings
• Probing charged lepton flavor violation with axion-like particles at Belle II
• ALPs and Heavy Hadron Chiral Perturbation Theory
• Kinematical Observables in Semi-Invisible Decays
• Search for lepton-flavor-violating decays of the tau lepton at a future muon collider