Direct measurement of the proton magnetic moment

Abstract

The proton magnetic moment in nuclear magnetons is measured to be μ p/μ Ng/2=2.792846±0.000007, a 2.5 parts per million uncertainty. The direct determination, using a single proton in a Penning trap, demonstrates the first method that should work as well with an antiproton (p̄) as with a proton (p). This opens the way to measuring the p̄ magnetic moment (whose uncertainty has essentially not been reduced for 20 years) at least 103 times more precisely. © 2012 American Physical Society.