An improved direct limit on the muon electric dipole moment
D. P. Aguillard, T. Albahri, D. Allspach, J. Annala, K. Badgley, S. Baeßler, E. Barlas-Yucel, E. Barzi, F. Bedeschi, M. Berz, M. Bhattacharya, H. P. Binney, P. C. Bloom, J. Bono, E. Bottalico, T. Bowcock, M. Bressler, G. Cantatore, B. C. K. Casey, D. Cauz · Research Explorer (The University of Manchester) · 2026
A limit on the permanent electric dipole moment (EDM) of the positive muon is presented based on data from the Fermilab Muon g-2 Experiment taken between 2019 and 2020. The tracking detectors measure the average vertical decay angle of positrons from muon decays, enabling a search for an interaction between a possible muon EDM $d_μ$ and the lab-frame magnetic field. The result, $d_μ= (-0.35 \pm 0.19_{\mathrm{stat}} \pm 0.34_{\mathrm{sys}}) \times10^{-19}~e\cdot$cm, is consistent with zero and sets a new direct limit on the muon EDM of $|d_μ|