Pseudoscalar bosonic excitations in the color-flavor locked phase at moderate densities

TL;DR

This paper investigates pseudoscalar bosonic excitations in the color-flavor locked phase at moderate densities using a Nambu--Jona-Lasinio model, analyzing their masses, decay constants, and bound states.

Contribution

It extends previous analysis to include hidden flavor Goldstone bosons and higher-lying modes, explicitly constructing bosons via Bethe-Salpeter equations.

Findings

Goldstone bosons' masses and decay constants match low-energy predictions.

Identifies a weakly bound SU(3) octet in the non-Goldstone sector.

Singlet mode appears unbound.

Abstract

The properties of pseudoscalar bosonic excitations in the color-flavor locked phase at moderate densities are studied within a model of the Nambu--Jona-Lasinio type. Our previous analysis is extended to Goldstone bosons with hidden flavor and to higher-lying modes which stay massive in the chiral limit. The bosons are constructed explicitly by solving the Bethe-Salpeter equation for quark-quark scattering in random phase approximation. The masses and weak decay constants of the Goldstone bosons are found in good agreement with predictions from the low-energy effective theory. In the non-Goldstone sector we find an SU(3) octet which is weakly bound, while the singlet appears to be unbound.