Colored condensates deep inside neutron stars

TL;DR

This paper develops a QCD-inspired model to describe the equation of state inside neutron stars, highlighting the role of diquark condensates and symmetry restoration at high densities.

Contribution

It introduces a model based on QCD symmetries to describe dense matter in neutron stars, incorporating color and chiral symmetry dynamics.

Findings

Strong diquark condensates support the existence of massive neutron stars.

Chiral symmetry is restored at high densities in the model.

Color symmetry is broken by diquark formation in dense quark matter.

Abstract

It is demonstrated how in the absence of solutions for QCD under conditions deep inside compact stars an equation of state can be obtained within a model that is built on the basic symmetries of the QCD Lagrangian, in particular chiral symmetry and color symmetry. While in the vacuum the chiral symmetry is spontaneously broken, it gets restored at high densities. Color symmetry, however, gets broken simultaneously by the formation of colorful diquark condensates. It is shown that a strong diquark condensate in cold dense quark matter is essential for supporting the possibility that such states could exist in the recently observed pulsars with masses of 2 $M_\odot$.