Equation of state and symmetry energy in heavy-ion collisions

The RAON is expected to provide extremely rare isotope beams with unprecedented isospin asymmetry for studies of nuclear structure, nuclear astrophysics, and nuclear reaction dynamics. Neutron-rich isotope beams are useful for investigating in detail the nuclear equation of state and the symmetry energy, which are essential for understanding astronomical objects like neutron stars and supernovae. At the RAON, low beam energies below 18.5 MeV/u are suitable for symmetryenergy research at subsaturation densities, and high beam energies around 250 MeV/u are ideal for such research at supra-saturation densities. Some examples of representative observables for studying the symmetry energy are the electric dipole emission, isospin diffusion of charged hadrons, collective-flow parameters, and pion yield ratio. This review article describes a plan for studying the nuclear equation of state and the symmetry energy that can be pursued in heavy-ion collisions at the RAON.