Heavy calcium nuclei weigh in

摘要

Perhaps the most fundamental observable property in nuclear physics is the mass of an atomic nucleus, which is related to how strongly the protons and neutrons within are bound. On page 346 of this issue, Wienholtz and collaborators report precise measurements of the masses of two shortlived, neutron-rich calcium nuclei, calcium-53 and calcium-54, which until now researchers have been unable to weigh. By comparing the measured masses with state-of-the-art model calculations aimed at describing the properties of atomic nuclei at a microscopic level, the authors have confirmed the unique role of calcium nuclei in deciphering the ingredients of the nuclear force that binds protons and neutrons together.