Calcium-48's 'neutron skin' thinner than previously thought
An international team led by Gaute Hagen of the Department of Energy's Oak Ridge National Laboratory used America's most powerful supercomputer, Titan, to compute the neutron distribution and related observables of calcium-48, an isotope with an atomic nucleus consisting of 20 protons and 28 neutrons. Computing the nucleus from first principles revealed that the difference between the radii of neutron and proton distributions (called the "neutron skin") is considerably smaller than previously thought. The collaboration also made predictions for physical quantities that are current targets of precision measurements. These calculations also impact the size of a neutron star, thereby connecting objects that differ in size by 18 orders of magnitude. The work is published in the journal Nature Physics.