Neutron star structure with nuclear force mediated by hypothetical X17 boson

TL;DR

This study explores how a hypothetical 17 MeV boson, proposed to explain certain nuclear anomalies, could influence neutron star structure by modifying the nuclear equation of state, resulting in an estimated maximum mass around 2.4 solar masses.

Contribution

It introduces the impact of a hypothetical X17 boson on neutron star equations of state and estimates the maximum neutron star mass considering this new physics.

Findings

Estimated neutron star maximum mass around 2.4 solar masses.

The modified equation of state aligns with recent neutron star merger observations.

The presence of the X17 boson affects the star's radius and mass limits.

Abstract

A reported ${17~}$MeV boson, which has been proposed as an explanation to the $^{8}$Be and $^{4}$He anomaly, is investigated in the context of its possible influence to neutron stars structure. Implementing a $m_{X}$=17 MeV to the nuclear equation of state using different incompressibility values K$_{0}$=245 MeV and K$_{0}$=260 MeV and solving Tolman-Oppenheimer-Volkoff equations, we estimate an upper limit of ${M_{TOV}\thickapprox 2.4M\odot}$ for a non rotating neutron star with span in radius ${R}$ between ${11.5~}$km to ${14~}$km. Moving away from pure - NN with admixture of 10\% protons and simulating possible softening of equation of state due to hyperons, we see that our estimated limits fit quite well inside the newest reported studies, coming from neutron stars merger event, GW190814