Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

Journal Article · Wed Apr 07 00:00:00 EDT 2021 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.126.141801· OSTI ID:1774725

Abi, B.; Albahri, T.; Al-Kilani, S.; Allspach, D.; Alonzi, L. P.; Anastasi, A.; Anisenkov, A.; Azfar, F.; Badgley, K.; Baeßler, S.; Bailey, I.; Baranov, V. A.; Barlas-Yucel, E.; Barrett, T.; Barzi, E.; Basti, A.; Bedeschi, F.; Behnke, A.; Berz, M.; Bhattacharya, M. ; Binney, H. P.; Bjorkquist, R.; Bloom, P.; Bono, J.; Bottalico, E.; Bowcock, T.; Boyden, D.; Cantatore, G.; Carey, R. M.; Carroll, J.; Casey, B. C. K.; Cauz, D.; Ceravolo, S.; Chakraborty, R.; Chang, S. P.; Chapelain, A.; Chappa, S.; Charity, S.; Chislett, R.; Choi, J.; Chu, Z.; Chupp, T. E.; Convery, M. E.; Conway, A.; Corradi, G.; Corrodi, S.; Cotrozzi, L.; Crnkovic, J. D.; Dabagov, S.; De Lurgio, P. M.; Debevec, P. T.; Di Falco, S.; Di Meo, P.; Di Sciascio, G.; Di Stefano, R.; Drendel, B.; Driutti, A.; Duginov, V. N.; Eads, M.; Eggert, N.; Epps, A.; Esquivel, J.; Farooq, M.; Fatemi, R.; Ferrari, C.; Fertl, M.; Fiedler, A.; Fienberg, A. T.; Fioretti, A.; Flay, D.; Foster, S. B.; Friedsam, H.; Frlež, E.; Froemming, N. S.; Fry, J.; Fu, C.; Gabbanini, C.; Galati, M. D.; Ganguly, S.; Garcia, A.; Gastler, D. E.; George, J.; Gibbons, L. K.; Gioiosa, A.; Giovanetti, K. L.; Girotti, P.; Gohn, W.; Gorringe, T.; Grange, J.; Grant, S.; Gray, F.; Haciomeroglu, S.; Hahn, D.; Halewood-Leagas, T.; Hampai, D.; Han, F.; Hazen, E.; Hempstead, J.; Henry, S.; Herrod, A. T.; Hertzog, D. W. ; Hesketh, G.; Hibbert, A.; Hodge, Z.; Holzbauer, J. L.; Hong, K. W.; Hong, R.; Iacovacci, M.; Incagli, M.; Johnstone, C.; Johnstone, J. A.; Kammel, P.; Kargiantoulakis, M.; Karuza, M.; Kaspar, J.; Kawall, D.; Kelton, L.; Keshavarzi, A.; Kessler, D.; Khaw, K. S.; Khechadoorian, Z.; Khomutov, N. V.; Kiburg, B.; Kiburg, M.; Kim, O.; Kim, S. C.; Kim, Y. I.; King, B.; Kinnaird, N.; Korostelev, M.; Kourbanis, I.; Kraegeloh, E.; Krylov, V. A.; Kuchibhotla, A.; Kuchinskiy, N. A.; Labe, K. R.; LaBounty, J.; Lancaster, M.; Lee, M. J.; Lee, S.; Leo, S.; Li, B.; Li, D.; Li, L.; Logashenko, I.; Lorente Campos, A.; Lucà, A.; Lukicov, G.; Luo, G.; Lusiani, A.; Lyon, A. L.; MacCoy, B.; Madrak, R.; Makino, K.; Marignetti, F.; Mastroianni, S.; Maxfield, S.; McEvoy, M.; Merritt, W.; Mikhailichenko, A. A.; Miller, J. P.; Miozzi, S.; Morgan, J. P.; Morse, W. M.; Mott, J.; Motuk, E.; Nath, A.; Newton, D.; Nguyen, H.; Oberling, M.; Osofsky, R.; Ostiguy, J. -F.; Park, S.; Pauletta, G.; Piacentino, G. M.; Pilato, R. N.; Pitts, K. T.; Plaster, B.; Počanić, D.; Pohlman, N.; Polly, C. C.; Popovic, M.; Price, J.; Quinn, B.; Raha, N.; Ramachandran, S.; Ramberg, E.; Rider, N. T.; Ritchie, J. L.; Roberts, B. L.; Rubin, D. L.; Santi, L.; Sathyan, D.; Schellman, H.; Schlesier, C.; Schreckenberger, A.; Semertzidis, Y. K.; Shatunov, Y. M.; Shemyakin, D.; Shenk, M.; Sim, D.; Smith, M. W.; Smith, A.; Soha, A. K.; Sorbara, M.; Stöckinger, D.; Stapleton, J.; Still, D.; Stoughton, C.; Stratakis, D.; Strohman, C.; Stuttard, T.; Swanson, H. E.; Sweetmore, G.; Sweigart, D. A.; Syphers, M. J.; Tarazona, D. A.; Teubner, T.; Tewsley-Booth, A. E.; Thomson, K.; Tishchenko, V.; Tran, N. H.; Turner, W.; Valetov, E.; Vasilkova, D.; Venanzoni, G.; Volnykh, V. P.; Walton, T.; Warren, M.; Weisskopf, A.; Welty-Rieger, L.; Whitley, M.; Winter, P.; Wolski, A.; Wormald, M.; Wu, W.; Yoshikawa, C.

We present the first results of the Fermilab Muon g-2 Experiment for the positive muon magnetic anomaly $$a_\mu \equiv (g_\mu-2)/2$$. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency $$\omega_a$$ between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency $${\tilde{\omega}'^{}_p}$$ in a spherical water sample at 34.7$$^{\circ}$$C. The ratio $$\omega_a / {\tilde{\omega}'^{}_p}$$, together with known fundamental constants, determines $$a_\mu({\rm FNAL}) = 116\,592\,040(54)\times 10^{-11}$$ (0.46\,ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both $$\mu^+$$ and $$\mu^-$$, the new experimental average of $$a_\mu({\rm Exp}) = 116\,592\,061(41)\times 10^{-11}$$ (0.35\,ppm) increases the tension between experiment and theory to 4.2 standard deviations

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States); Argonne National Laboratory (ANL), Argonne, IL (United States); Univ. of Illinois at Urbana-Champaign, IL (United States); Univ. of Mississippi, Oxford, MS (United States); Cornell Univ., Ithaca, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); USDOE Office of Science (SC), Nuclear Physics (NP); Marie Skłodowska-Curie Grant; National Science Foundation (NSF); Istituto Nazionale di Fisica Nucleare (INFN); United Kingdom Science and Technology Facilities Council; National Natural Science Foundation of China (NSFC); German Research Foundation (DFG)
• Contributing Organization: Muon g-2 Collaboration; Muon g−2 Collaboration
• Grant/Contract Number: AC02-07CH11359; 690835; 734303; 11975153; 12075151; SC0012704; AC02-06CH11357; SC0015640; SC0012391; SC0008037
• OSTI ID: 1774725
• Alternate ID(s): OSTI ID: 1775506; OSTI ID: 1778908; OSTI ID: 1781812; OSTI ID: 1865364; OSTI ID: 1882694; OSTI ID: 1908505
• Report Number(s): FERMILAB-PUB-21-132-E; arXiv:2104.03281; BNL-221301-2021-JAAM; PRLTAO; 141801
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Vol. 126 Journal Issue: 14; ISSN 0031-9007
• Publisher: American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
Magnetic moment
muons
accelerators & storage rings
precision measurements