Multi-Quark Clustering in Neutron-Star Matter from Color-Spin Molecular Dynamics

TL;DR

This paper investigates the equation of state of neutron-star matter using color-spin molecular dynamics, revealing multi-quark clustering and the influence of strangeness on neutron-star radii.

Contribution

It introduces a framework that includes color and spin degrees of freedom to study quark clustering and its effects on neutron-star properties.

Findings

Multi-quark clusters tend to have sizes that are multiples of three.

Isolated quark-like configurations do not appear under the studied conditions.

Strangeness significantly impacts neutron-star radii.

Abstract

We study the equation of state of neutron-star matter with color-spin molecular dynamics. The calculation includes the internal color and spin degrees of freedom and their time evolution. The matter composition, including strangeness under beta equilibrium, is determined by energy minimization. We find two main trends. First, within the present CSMD framework and under the adopted clustering criterion along the stable neutron-star branch, isolated quark-like configurations do not appear; instead, color-magnetic interactions favor the self-consistent formation of multi-quark clusters. Within the same criterion, the cluster-size distribution is concentrated at quark numbers that are multiples of three, corresponding to integer baryon numbers. Second, the interaction between strange and light quarks has a strong impact on neutron-star radii. This suggests that future radius measurements may help constrain flavor-sector interactions, including those involving strangeness.