Precision Measurement of Muon g-2 at BNL

TL;DR

The BNL Muon g-2 experiment achieved a highly precise measurement of the muon's anomalous magnetic moment, confirming previous results and hinting at potential new physics beyond the Standard Model.

Contribution

This paper reports the most precise measurement of muon g-2 to date, aligning with prior data and setting the stage for future analyses to explore deviations from the Standard Model.

Findings

Measured a_mu^+ = 11 659 202(14)(6) x 10^{-10}

Result agrees with previous measurements

Difference from Standard Model is 43(16) x 10^{-10}

Abstract

The Muon (g-2) Experiment (E821) at Brookhaven National Laboratory (BNL) has measured the anomalous magnetic moment of the positive muon to an unprecedented precision of 1.3 parts per million. The result, a_{\mu^+} = (g-2)/2 = 11 659 202(14)(6) X 10^{-10}, is based on data recorded in 1999 and is in good agreement with previous measurements. Upcoming analysis of data recorded in 2000 and 2001 will substantially reduce the uncertainty on this measurement. Comparison of the new world average experimental value with the most comprehensive Standard Model calculation, a_\mu(SM) = 11 659 159.6(6.7) X 10^{-10}, yields a difference of a_\mu(exp)-a_\mu(SM) = 43(16) X 10^{-10}.