Resumen de Proton gives mass measurers the slip again
Something isn't measuring up. For the second time, an extremely precise measurement of the proton's mass is different from its recognized value. The issue first raised its head in 2015, when a team led by Edmund Myers at Florida State University measured the difference in masses of the nucleus of a helium-3 atom and a deuteron--the nucleus of a deuterium or heavy hydrogen atom--with a single proton bound to it. Both contain two protons, one neutron and one electron, but because they are bound together differently, their masses are different
