Symmetry Energy of 2+1-flavor dense quark matter from perturbative QCD

TL;DR

This paper extends the concept of symmetry energy to dense quark matter using perturbative QCD, revealing small skewness and potential non-monotonic behavior in the symmetry energy at high densities.

Contribution

It develops a symmetry energy expansion for quark matter and applies next-to-leading-order pQCD calculations including realistic quark masses.

Findings

pQCD at electroweak equilibrium shows a small skewness in symmetry energy

Predicted a non-monotonic dip in symmetry energy if nuclear EoS matches pQCD

Derived symmetry energy properties unique to quark matter compared to hadronic matter

Abstract

The symmetry energy expansion was developed to connect isospin symmetric matter probed in nuclear experiments to asymmetric matter found in neutron stars. Using the isospin asymmetry derived from the Gell-Mann-Nishijima formula, we derive the symmetry energy expansion for quark matter that has unique properties compared to hadronic matter. To test our methods, we use perturbative Quantum Chromodynamics (pQCD) calculations at next-to-leading-order, where realistic quark masses can be included. We find that pQCD at electroweak equilibrium is not isospin symmetric but rather obtains a small skewness term in the symmetry energy expansion. We predict that if equations of state for nuclear matter must match pQCD results, then a non-monotonic dip in the symmetry energy would appear.