August 10, 2013
The International Collaborations in Nuclear Theory (ICNT) program concluded this week at the Facility for Rare Isotope Beams (FRIB) at Michigan State University with discussions mapping out plans for future theoretical, experimental, and observational work on the nuclear symmetry energy. Understanding how the energy of nuclear matter rises as one goes away from equal numbers of neutrons and protons allows scientists to extrapolate to very neutron rich systems in astrophysics. Indeed, the symmetry energy at high densities is the single laboratory observable most closely related to the structure of neutron stars.
The four-week ICNT program (July 15 to August 9) emphasized the close interplay between heavy ion collisions, nuclear structure measurements, and astronomical observations. Highlights from the program include new observations of neutron star radii, new opportunities to simulate supernova conditions with radioactive beams, and plans for a transport code archive to improve theoretical descriptions of heavy ion collisions.
Heavy ion collisions with radioactive beams allow new opportunities to simulate the warm neutron rich conditions inside a supernova where the neutrinos are emitted. These conditions are important for nucleosynthesis.
Transport codes allow computer simulations of heavy ion collisions by following the trajectories and collisions of the neutrons and protons. Interpretation of experimental results relies heavily on transport model calculations. The development of an archive to store and compare these codes will improve the accuracy and reliability of theoretical predictions.
About eighty scientists from all over the world participated in the ICNT program and workshop talks can be found online at http://www.nucl.phys.tohoku.ac.jp/icnt2013/program.html. It is anticipated that this is the first in a continuing series of ICNT programs addressing problems of direct relevance to FRIB.