New physics explanations of aμ in light of the FNAL muon g-2 measurement

The Fermilab Muon g -2 experiment recently reported its first measurement of the anomalous magnetic moment a(mu)(FNAL), which is in full agreement with the previous BNL measurement and pushes the world average deviation Delta a(mu)(20)(21) from the Standard Model to a significance of 4.2 sigma. Here we provide an extensive survey of its impact on beyond the Standard Model physics. We use state-of-the-art calculations and a sophisticated set of tools to make predictions for a(mu), dark matter and LHC searches in a wide range of simple models with up to three new fields, that represent some of the few ways that large Delta a(mu) can be explained. In addition for the particularly well motivated Minimal Supersymmetric Standard Model, we exhaustively cover the scenarios where large Delta a(mu) can be explained while simultaneously satisfying all relevant data from other experiments. Generally, the a(mu) result can only be explained by rather small masses and/or large couplings and enhanced chirality flips, which can lead to conflicts with limits from LHC and dark matter experiments. Our results show that the new measurement excludes a large number of models and provides crucial constraints on others. Two-Higgs doublet and leptoquark models provide viable explanations of a(mu) only in specific versions and in specific parameter ranges. Among all models with up to three fields, only models with chirality enhancements can accommodate a(mu) and dark matter simultaneously. The MSSM can simultaneously explain a(mu) and dark matter for Bino-like LSP in several coannihilation regions. Allowing under abundance of the dark matter relic density, the Higgsino- and particularly Wino-like LSP scenarios become promising explanations of the a(mu) result.

Automated summary

The Fermilab Muon g -2 experiment's measurement of the anomalous magnetic moment has significant implications for physics beyond the Standard Model, with constraints on models explaining large deviations and the need for considerations of mass, coupling, and chirality. It excludes many models and highlights the importance of specific parameter ranges in explaining the results.