Constraints on the Equation of State of Nuclear Matter from Heavy-Ion Collisions and from Structure

Mar 24, 2014, 9:50 AM


Prof. Pawel Danielewicz (East Lansing, MSU (USA))


Constraints on the nuclear equation of state, following from heavy ion collisions and from structure, are reviewed. The collisions produce matter transiently reaching densities few times the normal. Isolating observables testing such densities is challenging, though, and interpretation of those observables suffers from theoretical uncertainities. Structure observables can be generally accurately determined, but test only densities up to normal and are sensitive to poorly controlled microscopic effects. In spite of the difficulties, through gradual progress, it became possible to constrain the equation of state of symmetric matter at densities few times the normal, using anisotropic collective flow and kaon yields as crucial observables. Nuclear incompressibility was constrained using energies of giant monopole resonances, excited through alpha scattering. The current laboratory efforts concentrate on the role of neutron-proton asymmetry in the nuclear equation of state. Advances made on the collision and structure side, including studying of mass systematics, produced constraints on symmetry energy at subnormal densities. Limited progress, though, was made so far with regard to the symmetry energy at supranormal densities, important for extrapolations from nuclei to neutron stars. The greatest promise among observables is held by the charged pion yields which test neutron-proton composition of high-density matter in collisions, regulated itself by the high-density symmetry energy.

Primary author

Prof. Pawel Danielewicz (East Lansing, MSU (USA))

Presentation materials