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arXiv · 2305.19376

Density Dependence of the Symmetry Energy in the Post PREX-CREX Era

Brendan T. Reed·F. J. Fattoyev·C. J. Horowitz·J. Piekarewicz
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Abstract

The recently published CREX results suggest a rather peculiar picture for the density dependence of the symmetry energy. Whereas PREX favors a large neutron skin thickness in $^{208}$Pb, thereby suggesting a stiff equation of state, CREX suggests instead a much softer equation of state. This discrepancy has caused a large spur in the theoretical community since no model has been able to simultaneously reproduce within $1\sigma$ the PREX and CREX results. Motivated by a novel correlation between a CREX observable and a combination of bulk symmetry energy parameters, we calibrate three new covariant energy density functionals that reproduce binding energies and charge radii of spherical nuclei - and also accommodate the constraints imposed by PREX and CREX. Given that these models suggest a stiff equation of state at high densities, predictions for neutron star properties are also discussed.

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Brendan T. Reed, F. J. Fattoyev, C. J. Horowitz, J. Piekarewicz. 2023-05-30. Density Dependence of the Symmetry Energy in the Post PREX-CREX Era. https://arxiv.org/abs/2305.19376

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