18237 2112.08377 10.1007/JHEP04(2022)129 129 129 Systematically testing singlet models for (g − 2) μ Regular Article - Theoretical Physics 1 37 2022 4 22 2022 2 1 2022 3 24 2022 4 22 The Author(s) 2022 Open Access. This article is distributed under the terms of the Creative Commons Attribution License ( CC-BY 4.0 ), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. 13130 2022 2022 4 4 Rodolfo Capdevilla rcapdevilla@perimeterinstitute.ca David Curtin dcurtin@physics.utoronto.ca Yonatan Kahn yfkahn@illinois.edu Gordan Krnjaic krnjaicg@fnal.gov grid.17063.33 0000 0001 2157 2938 Department of physics, University of Toronto Saint George Street Toronto Ontario Canada grid.420198.6 0000 0000 8658 0851 Perimeter Institute for Theoretical Physics Caroline Street North Waterloo Ontario Canada grid.35403.31 0000 0004 1936 9991 Department of Physics, University of Illinois at Urbana-Champaign West Green Street Urbana IL USA grid.35403.31 0000 0004 1936 9991 Illinois Center for Advanced Studies of the Universe, University of Illinois at Urbana-Champaign West Green Street Urbana IL USA grid.417851.e 0000 0001 0675 0679 Fermi National Accelerator Laboratory Kirk Street Batavia IL USA grid.170205.1 0000 0004 1936 7822 Department of Astronomy and Astrophysics, University of Chicago South Ellis Avenue Chicago IL USA grid.170205.1 0000 0004 1936 7822 Kavli Institute for Cosmological Physics University of Chicago South Ellis Avenue Chicago IL USA Abstract We comprehensively study all viable new-physics scenarios that resolve the muon (g − 2) μ 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 (NA64μ, 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 O 100 GeV $$ \mathcal{O}\left(100\ \mathrm{GeV}\right) $$ 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. Keywords New Gauge Interactions New Light Particles Specific BSM Phenomenology ArXiv ePrint: 2112.08377