In a paper published in the journal Science, a team of physicists from Japan and Germany reports the most precise measurement ever made of the magnetic moment of the proton, allowing a fundamental comparison between matter and antimatter. The new result improves by a factor 11 the precision of the previous measurement, and is consistent with the currently accepted value. Protons are positively-charged particles in atomic nuclei. In addition to an electric charge they also have an intrinsic angular momentum, the spin, giving them a magnetic moment.
Although this fundamental property of the proton has no direct implication for current technology, it is instead of far greater significance for understanding atomic structures and for precisely testing fundamental symmetries in the Universe, in particular the imbalance of matter and antimatter.