High-density QCD pairing in compact star structure

Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo Rua do Matão 1226, (05508-900) São Paulo SP, Brazil e-mail: foton@astro.iag.usp.br

Corresponding author: G. Lugones, glugones@astro.iag.usp.br

Received: 2 December 2002
Accepted: 14 February 2003

Abstract

Strange quark matter in a color flavor locked (CFL) state can be the true ground state of hadronic matter for a much wider range of the parameters of the model (the gap of the QCD Cooper pairs Δ, the strange quark mass m_s and the Bag Constant B) than the state without any pairing. We review the equation of state (EOS) of CFL strange matter and study the structure of stellar objects made up of this phase, highlighting the novel features of the latter. Although the effects of pairing on the equation of state are thought to be small, we find that CFL stars may be in fact much more compact than strange stars (SS). This feature may be relevant in view of some recent observations claiming the existence of exotic and/or deconfined phases in some nearby neutron stars (NS).