UT-ORNL Study: Calcium-48’s ‘Neutron Skin’ Thinner Than Previously Thought

Physics_nucleusAn international team led by joint UT-Oak Ridge National Laboratory (ORNL) faculty used America’s most powerful supercomputer, Titan, to calculate the neutron distribution and related observables of calcium-48, an isotope with an atomic nucleus consisting of twenty protons and twenty-eight neutrons.

Computing the nucleus revealed that the difference between the radii of neutron and proton distributions—called the “neutron skin”—is considerably smaller than previously thought.

The calculations also affect the size of a neutron star, thereby connecting objects that differ in size by eighteen orders of magnitude. A neutron star is a city-size stellar object with a mass about 1.4 times that of the Sun. It is created from the explosion of larger stars.

The work is published in the journal Nature Physics.

Gaute Hagen, who holds a joint appointment at ORNL and in the UT Department of Physics and Astronomy, led the research team. Other UT physics researchers on the team are Andreas Ekström, Christian Forssén, Gustav Jansen, Thomas Papenbrock, and Kyle Wendt.

The team includes partners from Michigan State University, Chalmers University of Technology in Sweden, TRIUMF in Canada, Hebrew University in Israel, Technical University Darmstadt in Germany, the University of Oslo in Norway, and the University of Trento in Italy.

Continue reading on the ORNL website.