Tension between implications from PREX-2 data and gravitational tidal response on dense matter equation of state

TL;DR

This paper examines the tension between recent PREX-2 experimental data indicating high symmetry energy and astrophysical observations of neutron stars, using this discrepancy to constrain nuclear matter models and meson coupling parameters.

Contribution

The study explores the implications of PREX-2 data on dense matter equations of state and constrains meson coupling parameters based on the observed tension.

Findings

PREX-2 data suggests high symmetry energy and slope, outside astrophysical bounds.

Tension between terrestrial experiments and neutron star observations identified.

Constraints on $ ext{Delta}$-scalar meson coupling parameters derived.

Abstract

Recently an improved value of neutron skin thickness of $^{208}\text{Pb}$ was reported in Lead Radius EXperiment-2 (PREX-2) to be $R_{\text{skin}}=R_n - R_p=(0.283\pm 0.071)$ fm which corresponds to high estimations of nuclear symmetry energy ($E_{\text{sym}}$) and its slope ($L_{\text{sym}}$). The updated values of $E_{\text{sym}}$ and $L_{\text{sym}}$ commensurating to the neutron star observable estimations lie exterior to the astrophysical observed range. The higher values of $L_{\text{sym}}$ at $n_0$ deduced from recent PREX-2 data correlates to matter being easily deformable (yielding higher radius values) around intermediate matter densities leading to higher values of $\tilde{\Lambda}$ creating a tension between the terrestrial and astrophysical observations. In this study, we exploit this tension to constrain the $\Delta$-scalar meson coupling parameter space.