Antikaons and higher order couplings in relativistic-mean field study of neutron stars

Abstract

We investigate the role of higher order couplings, along with the condensation of antikaons ($K^{-}$ and ${\bar{K}}^0$), on the properties of neutron star (NS). We employ extended versions of the relativistic mean-field model, in which kaon-nucleon and nucleon-nucleon interactions are taken on the same footing. We find that the onset of condensation of $K^{-}$ and ${\bar{K}}^0$ highly depends not only on the strength of optical potential but also on the new couplings. The presence of antikaons leads to a softer equation of state and makes the neutron star core symmetric and lepton-deficient. We show that these effects strongly influence the mass-radius relation as well as the composition of neutron star. We also show that the recently observed 1.97$\pm$.04 solar mass NS can be explained in three ways: (i) a stiffer EoS with both antikaons, (ii) a relatively soft EoS with $K^{-}$ and (iii) a softer EoS without antikaons.

References in corpus (9)

• Shapiro delay measurement of a two solar mass neutron star
• Neutron-Rich Nuclei in Heaven and Earth
• Relativistic effective interaction for nuclei, giant resonances, and neutron stars
• The Mass and Radius of the Neutron Star in 4U 1820-30
• An Eccentric Binary Millisecond Pulsar in the Galactic Plane
• A Massive Neutron Star in the Globular Cluster M5
• A Second Relativistic Mean Field and Virial Equation of State for Astrophysical Simulations
• Determination of the mass of the neutron star in SMC X-1, LMC X-4 and Cen X-3 with VLT/UVES
• Role of higher order couplings in the presence of kaons in relativistic mean field description of neutron stars