Relativistic approach for the determination of nuclear and neutron star properties in consideration of PREX-II results

The bulk properties of nuclear matter and neutron stars with the newly generated relativisticinteraction Dev Bhoomi Himachal Pradesh (DBHP) are investigated, which provides an opportunity to modify the coupling parameters keeping in view the finite nuclei, nuclear matter, PREX-II data for neutron skin thickness in ${}^{208}\mathrm{Pb}$, and astrophysical constraints. The relativistic interaction has been generated by including all possible self and mixed interactions among $\sigma$, $\omega$, and $\rho$ mesons up to the quartic order satisfying the naturalness behavior of parameters. A covariance analysis is performed to assess the statistical uncertainties of the model parameters and observables of interest along with correlations amongst them. We obtained a value of neutron skin thickness for the ${}^{208}\mathrm{Pb}$ nucleus of $\mathrm{\Delta }{r}_{\mathrm{np}}=0.24\pm 0.02$ fm. The maximum gravitational mass of a neutron star and the radius corresponding to the canonical mass ($R_{1.4}$) come out to be $2.03\pm 0.04$ $M_{\odot }$ and $13.39\pm 0.41$ km, respectively. The dimensionless tidal deformability $\mathrm{\Lambda }$ for a neutron star is also analyzed.

Figure 1

Correlation coefficients among the model parameters for DBHP parametrization of the Lagrangian given by Eq. (1).

Figure 2

Relative error in the total binding energy ($\delta E$) plotted against the mass number ($A$) for the newly generated parameter set DBHP. For comparison, the values of $\delta E$ obtained with parameters NL3, IOPB-1, FSUGarnet, and Big Apple are also displayed.

Figure 3

Relative error in the charge root mean square ($\delta R_{\mathrm{ch}}$) plotted against the mass number ($A$) for the newly generated parameter set DBHP For comparison, the values obtained with parameters NL3, IOPB-1, FSUGarnet, and Big Apple are also displayed.

Figure 4

Variation of pressure as a function of baryon density for SNM (upper panel) and PNM (lower panel) computed with DBHP parametrization along with NL3, IOPB-1, FSUGarnet, and Big Apple models. The shaded region represents the experimental data taken from Ref. [27].

Figure 5

The density-dependent symmetry energy plotted as a function of baryon density for the DBHP model. The results are also displayed for NL3, IOPB-1, FSUGarnet, and Big Apple parameter sets.

Figure 6

Variation of pressure as a function of energy density for the DBHP parameter set. EOSs computed with NL3, IOPB-1, FSUGarnet, and Big Apple models are also shown for comparison. The shaded region represents the observational constraints taken from Ref. [56].

Figure 7

Relationship between neutron star mass and its radius for DBHP parametrization. The results are compared with NL3, IOPB-1, FSUGarnet, and Big Apple parameters.

Figure 8

Variation of dimensionless tidal deformability ($\mathrm{\Lambda }$) with respect to gravitational mass for DBHP parametrization. The results for NL3, IOPB-1, FSUGarnet, and Big Apple parameters are also shown.

Figure 9

Correlation coefficients between the model parameters and a set of neutron star observables as well as the bulk properties of nuclear matter at the saturation density for DBHP parametrization (see text for details).

Figure 10

Correlation coefficients for bulk nuclear matter and neutron star properties and neutron skin of ${}^{208}\mathrm{Pb}$ for DBHP parametrization.