Simultaneous explanation of XTE J1814-338 and HESS J1731-347 objects using ${K^{-}}$ and ${\bar{K}^{0}}$ condensates

TL;DR

This paper explores the presence of exotic kaon condensates in neutron stars to explain observed properties of specific compact objects, proposing a dual-branch model for diverse astrophysical phenomena.

Contribution

It introduces a novel relativistic mean field model incorporating ${K^{-}}$ and ${ar{K}^{0}}$ condensates to explain neutron star observations and suggests a two-branch scenario for different nuclear matter compositions.

Findings

Kaon condensates can account for observed neutron star masses and radii.

A dual-branch model explains the diversity of astrophysical objects.

The approach aligns with recent pulsar observations.

Abstract

The recent observation of the compact star XTE J1814-338 with a mass of $M=1.2^{+0.05}_{-0.05}~{\rm M_{\odot}}$ and a radius of $R=7^{+0.4}_{-0.4}$ km, together with the HESS J1731-347, which has a mass of $M=0.77^{+0.20}_{-0.17}~{\rm M_{\odot}}$ and a radius of $R=10.4^{+0.86}_{-0.78}$ km, shows they provide evidence for the possible presence of exotic matter in the core of neutron stars and significantly enhance our understanding of the equation of state for the dense nuclear matter. In the present study, we investigate the possible existence of negative charged kaons and neutral anti-kaons in neutron stars by employing the relativistic mean field model with first order kaonic (${K^{-}}$ and ${\bar{K}^{0}}$) condensates. To the best of our knowledge, this represents a first alternative attempt aimed to explain the bulk properties of the XTE J1814-338 object and at the same time the HESS J1731-347 object, using a mixture of kaons condensation in dense nuclear matter. In addition, we compare our analysis approach with the recent observation of PSR J0437-4715 and PSR J1231-1411 pulsars, proposing that to simultaneously explain the current variety of astrophysical objects, it is essential to resurrect a scenario of two distinct branches, each corresponding to a different composition of nuclear matter.