Systematically Testing Singlet Models for $(g-2{)}_{\mu }$

Abstract

We comprehensively study all viable new-physics scenarios that resolve the muon $(g-2{)}_{\mu }$ anomaly with only Standard Model singlet particles coupled to muons via renormalizable interactions. Since such models are only viable in the MeV -- TeV mass range and require sizable muon couplings, they predict abundant accelerator production through the same interaction that resolves the anomaly. We find that a combination of fixed-target (NA64$\mu$, $M^3$), $B$-factory (BABAR, Belle II), and collider (LHC, muon collider) searches can cover nearly all viable singlets scenarios, independently of their decay modes. In particular, future muon collider searches offer the only certain test of singlets above the GeV scale, covering all higher masses up to the TeV-scale unitarity limit for these models. Intriguingly, we find that $\mathcal{O}(100\mathrm{GeV})$ muon colliders may yield better coverage for GeV-scale singlets compared to TeV-scale concepts, which has important implications for the starting center-of-mass energy of a staged muon collider program.

28 pages, 11 figures. Added missing references in v2 and v3

References in corpus (16)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• FeynRules - Feynman rules made easy
• Secluded U(1) below the weak scale
• The $g-2$ of charged leptons, $\alpha (M_Z^2)$ and the hyperfine splitting of muonium
• Hadronic contribution to the muon anomalous magnetic moment to next-to-next-to-leading order
• Neutrino Trident Production: A Powerful Probe of New Physics with Neutrino Beams
• Cosmology With a Very Light $L_{\mu }-L_{\tau }$ Gauge Boson
• The muon $g$-2 and $\Delta \alpha$ connection
• Light-by-light scattering sum rules in light of new data
• The muon g-2 and the bounds on the Higgs boson mass
• Electromagnetic and strong isospin-breaking corrections to the muon $g-2$ from Lattice QCD+QED
• Vector boson fusion at multi-TeV muon colliders
• Revisiting the Dark Photon Explanation of the Muon Anomalous Magnetic Moment
• Probing electroweak phase transition with multi-TeV muon colliders and gravitational waves
• Combined search for light dark matter with electron and muon beams at NA64
• Multi-lepton signatures of vector-like leptons with flavor

Cited by in corpus (1)

• A Snowmass Whitepaper: Dark Matter Production at Intensity-Frontier Experiments