Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm
D. P. Aguillard, T. Albahri, D. Allspach, A. V. Anisenkov, K. Badgley, S. Baeßler, I. Bailey, Laura Bailey, V. A. Baranov, E. Barlas-Yucel, T. Barrett, E. Barzi, F. Bedeschi, Martin Berz, Meghna Bhattacharya, H. P. Binney, P. Bloom, J. Bono, E. Bottalico, T. J. V. Bowcock, S. Braun, M. Bressler, G. Cantatore, R. M. Carey, B. C. K. Casey, D. Cauz, R. Chakraborty, A. Chapelain, S. Chappa, S. Charity, Chen Cheng, M.-T. Cheng, R. T. Chislett, Z. Chu, T. E. Chupp, C. Claessens, M. E. Convery, S. Corrodi, L. Cotrozzi, J. Crnkovic, С.Б. Дабагов, P. T. Debevec, S. Di Falco, G. Di Sciascio, B. Drendel, A. Driutti, V. N. Duginov, M. Eads, A. Edmonds, J. Esquivel, M. Farooq, R. Fatemi, C. Ferrari, M. Fertl, Aaron Fienberg, A. Fioretti, D. Flay, S. B. Foster, H. Friedsam, Nathan Froemming, C. Gabbanini, I. Gaines, M. D. Galati, S. Ganguly, A. Garcı́a, J. George, L. Gibbons, A. Gioiosa, K. L. Giovanetti, P. Girotti, W. Gohn, L. Goodenough, T. P. Gorringe, J. Grange, S. Grant, F. Gray, Selçuk Hacıömeroğlu, T. Halewood-leagas, D. Hampai, F. Han, J. Hempstead, D. W. Hertzog, G. G. Hesketh, E. Hess, Angela Hibbert, Z. Hodge, K. W. Hong, R. Hong, T. Hu, Y. Hu, M. Iacovacci, M. Incagli, P. Kammel, M. Kargiantoulakis, M. Karuza, J. Kašpar, D. Kawall, L. Kelton, A. Keshavarzi, D. Kessler
Abstract
We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω[over ˜]_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From the ratio ω_{a}/ω[over ˜]_{p}^{'}, together with precisely determined external parameters, we determine a_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.