The size of most massive neutron stars may reveal its exotic cores

TL;DR

This paper investigates whether precise radius measurements of the most massive neutron stars can reveal the presence of exotic cores, challenging the idea that mass alone rules out such exotic compositions.

Contribution

It demonstrates that radius measurements, combined with mass data, can help determine the existence of exotic cores in massive neutron stars.

Findings

Radius sensitivity to core composition analyzed

Precise radius measurement can indicate exotic cores

Mass alone is insufficient to determine core composition

Abstract

The recent high precision observation of the most massive pulsar J1614-2230 with $(1.97\pm0.04)$ solar mass ($M_\odot$) was reported with a suggestion that many nuclear models which consider exotic particles in the core could be ruled out. However, many recent calculations could explain this star with various exotic particles, rendering the precise mass measurements insufficient to conclude on exotic cores. We examine the sensitivity of the radius of such a star to the details of its core. With our calculations and analysis, here we show that, for the most massive neutron star, with a precise observation of its radius it is possible to ascertain the presence of exotic cores.