New relativistic effective interaction for finite nuclei, infinite nuclear matter, and neutron stars

Abstract

We carry out the study for finite nuclei, infinite nuclear matter and neutron star properties with the newly developed relativistic force named as the Institute Of Physics Bhubaneswar-I(IOPB-I). Using this force, we calculate the binding energies, charge radii and neutron-skin thickness for some selected nuclei. From the ground state properties of superheavy nuclei (Z=120), it is noticed that considerable shell gaps appear at neutron numbers N=172, 184 and 198, manifesting the magicity at these numbers. The low-density behavior of the equation of state for pure neutron matter is compatible with other microscopic models. Along with the nuclear symmetry energy, its slope and curvature parameters at the saturation density are consistent with those extracted from various experimental data. We calculate the neutron star properties with the equation of state composed of nucleons and leptons in beta − equilibrium which are in good agreement with the X-ray observations by Steiner and Nättilä. Based on the recent observation GW170817 with a quasi-universal relation, L. Rezzolla et. al. have set a limit for the maximum mass that can be supported against gravity by a nonrotating neutron star is in the range 2.01 ± 0.04 M (M ) 2.16 ± 0.03. We find that the maximum mass of the neutron star for the IOPB-I parametrization is 2.15M . The radius and tidal deformability of a canonical neutron star mass 1.4M are 13.2 km and 3.9×10 36 g cm 2 s 2 respectively. PACS numbers: 26.60.+c, 26.60.Kp, 95.85.Sz

Constraining twin stars with GW170817

“…As for the limits on the radius of 1.4 M , several works have reported values for stars of a given mass [48,[51][52][53][54][55][56][57][58][59][60] and we have collected them in Table II. Also, we recall that in Ref.…”

“…The recent detection by the Advanced LIGO and Virgo collaborations [49,50] of gravitational waves from merging compact stars, GW170817, has provided important new insights on the maximum mass and on the radius of neutron stars by means of the measurement of tidal deformabilities in a binary system [43,[45][46][47][48][51][52][53][54][55][56][57][58][59][60]. We recall that the tidal deformability measures the induced quadrupole moment of a star in response to the tidal field of its companion, i.e., it determines how easily a star is deformed in a binary system [61].…”

Implications of the fermion vacuum term in the extended SU(3) quark meson model on compact star properties

“…The resulting equations of state (EoSs) have been used to calculate mass radius relations of compact stars. These mass radius relations have to respect the 2M ⊙ limit [45][46][47][48] and the constraints coming from the analysis of the tidal deformabilities of the GW170817 neutron star merger event [50,[54][55][56][57][58][59][60]. We compare our results from the extended mean field approximation (eMFA) with the mean field approximation (MFA).…”

“…(48) on a logarithmic scale for a 1.4M ⊙ star as a function of the radius of a 1.4M ⊙ star. The shaded area fulfills both constraints on either R ≤ 13.5 km [54][55][56][57][58][59][60][61] and Λ ≤ 720 [50]. The c 2 s curve corresponds to the MIT Bag model EoS p = c 2 s ǫ − 4B, and is obtained for different values of the vacuum pressure constant B.…”

“…The GW170817 measurement on the tidal deformability deduces Λ = 300 +420 −230 for a 1.4M ⊙ star [50]. Inferred from that measurement, the radius of a 1.4M ⊙ star cannot be larger than R ≥ 13.5 km [54][55][56][57][58][59][60][61]. The mass radius relations of the eMFA are compared to those of the standard mean field approximation (MFA).…”