Perturbative QCD and the Neutron Star Equation of State

Rahul Somasundaram (1) , Ingo Tews , Jérôme Margueron (1)

1 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon

We construct a physics-agnostic approach to the neutron star (NS) equation of state (EoS) based on a sound speed model, which connects both low-density information from nuclear theory and high-density constraints from perturbative QCD (pQCD). Using this approach, we study the impact of pQCD calculations on NS EoS that have been constrained by astrophysical observations. We find that pQCD affects the EoS mainly beyond the densities realised in NS. Furthermore, we observe an interesting interplay between pQCD and astrophysical constraints, with pQCD preferring softer EoS for the heaviest NS while recent NICER observations suggest the EoS to be stiffer. We explore the sensitivity of our findings to pQCD uncertainties and study the constraining power of pQCD if future observations of heavy NS were to suggest radii larger than 13 km.

Mots clés: quantum chromodynamics: perturbation theory; velocity: acoustic; neutron star; equation of state; density; sensitivity; nucleus

Domaines: Physique Nucléaire Théorique [nucl-th]

Rahul Somasundaram, Ingo Tews, Jérôme Margueron. Perturbative QCD and the Neutron Star Equation of State. Phys.Rev.C, 2023, 107 (5), pp.L052801. ⟨10.1103/PhysRevC.107.L052801⟩. ⟨hal-03668750⟩