Critical temperature for kaon condensation in color-flavor locked quark matter

TL;DR

This paper investigates the temperature at which kaon Bose-Einstein condensation melts in color-flavor-locked quark matter, using an effective bosonic theory to determine the transition temperature relevant for transport properties.

Contribution

It provides a self-consistent calculation of the melting temperature of kaon condensation in CFL quark matter using the two-particle irreducible effective action approach.

Findings

Determined the temperature-dependent kaon masses.

Calculated the transition temperature for kaon condensation.

Analyzed implications for transport properties like bulk viscosity.

Abstract

We study the behavior of Goldstone bosons in color-flavor-locked (CFL) quark matter at nonzero temperature. Chiral symmetry breaking in this phase of cold and dense matter gives rise to pseudo-Goldstone bosons, the lightest of these being the charged and neutral kaons K^+ and K^0. At zero temperature, Bose-Einstein condensation of the kaons occurs. Since all fermions are gapped, this kaon condensed CFL phase can, for energies below the fermionic energy gap, be described by an effective theory for the bosonic modes. We use this effective theory to investigate the melting of the condensate: we determine the temperature-dependent kaon masses self-consistently using the two-particle irreducible effective action, and we compute the transition temperature for Bose-Einstein condensation. Our results are important for studies of transport properties of the kaon condensed CFL phase, such as bulk viscosity.