Trends of nuclear matter and neutron-star observables post CREX-PREX-II results within the relativistic mean field model

The recently precise parity-violating electron scattering experiments CREX and PREX-II results on neutron skin thickness for 48Ca and 208Pb nucleus suggest a distinctive picture of linear density dependence of symmetry energy (L) and equation of state (EoS) of dense nuclear matter. The PREX-II results demand a large value of L, suggesting stiffer EoS, whereas CREX results support small L and softer EoS. This discrepancy has caused large tension among theoretical, experimental, and observational groups to reproduce the ground state properties of finite nuclei, simultaneously satisfying the CREX-PREX results and properties of neutron stars within the astrophysical observations. Motivated by this, we propose the interactions for the relativistic mean field (RMF) model by taking into account the coupling of isovector scalar 8 meson-nucleon (g8), cubic (Q82) and quartic order interactions ( r282) due to isoscalar scalar a and isovector scalar, 8 mesons, in addition to vector meson mixing w2 rho 2. These interactions reproduce the binding energies and charge radii of spherical/closed shell nuclei and also satisfy the CREX and PREX-II results on neutron skin thickness for 48Ca and 208Pb nucleus and give a plausible solution to the CREX-PREX-II dilemma. It is also observed that for the RMF model to satisfy the CREX-PREX-II constraints simultaneously, L should lie in the range 79.32 +/- 6.20 MeV. The equations of state composed of /3-equilibrated nucleonic matter obtained for these interactions are very stiff. The prediction of nuclear matter and neutron star observables for these interactions are also discussed.