Four ppm measurement of the antihydrogen ground-state hyperfine splitting
27 May 2026 at 01:00
Nature, Published online: 27 May 2026; doi:10.1038/s41586-026-10556-x
A measurement of the hyperfine splitting energy of the ground state of antihydrogen at 4 ppm precision reaches a point at which this result is sensitive to the internal structure of the antiproton.