Constraining equation of state of nuclear matter by cross section measurements of mirror nuclei

The nuclear symmetry energy plays a key role in determining the equation of state (EoS) of dense, neutron-rich matter, which connects the atomic nuclei with the hot and dense matter in universe, thus has been the subject of intense investigations in laboratory experiments, astronomy observations and theories. Various probes have been proposed to constrain the symmetry energy and its density dependence. Currently, the extensive data yield already a good and consistent constraint to the symmetry energy (E-sym(rho)) at saturation density, but do not yet give a consistent result of one critical EoS parameter, L, the density dependence of the symmetry energy. In this work, we report a new probe of L at saturation density. A good linear correlation is found between L and the charge changing cross section difference (Delta sigma(cc)) of mirror nuclei Si-30-(3)(0) S for both the Skyrme-Hartree-Fock theory (SHF) and covariant (relativistic) density functionals (CDF). We found that the pairing effect for this mirror pair is essential to get a consistent correlation between L and Delta sigma(cc) in both the SHF and CDF. Here, the cross sections are calculated on the same target and at the same energy using the zero-range optical-limit Glauber model. The linearity is found to be in the same precision as those found between L and neutron skin thickness or proton radius difference. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

The nuclear symmetry energy has a significant impact on determining the equation of state of dense, neutron-rich matter. However, the density dependence parameter L of the symmetry energy is yet to be consistently determined. This study presents a new method to constrain L at saturation density by establishing a linear correlation between L and the charge changing cross section difference of mirror nuclei Si-30-(3)(0) S.