New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces

We present precision Penning trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system, the mass of K51 was measured for the first time, and the precision of the Ca51,52 mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, Ca52 is more bound by 1.74MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces. © 2012 American Physical Society.

Duke Scholars

Author Jens Dilling Physics