Goldstone boson counting in linear sigma models with chemical potential

Abstract

We analyze the effects of finite chemical potential on spontaneous breaking of internal symmetries within the class of relativistic field theories described by the linear sigma model. Special attention is paid to the emergence of ``abnormal'' Goldstone bosons with quadratic dispersion relation. We show that their presence is tightly connected to nonzero density of the Noether charges, and formulate a general counting rule. The general results are demonstrated on an SU(3)xU(1) invariant model with an SU(3)-sextet scalar field, which describes one of the color-superconducting phases of QCD.

10 pages, REVTeX4, 4 eps figures, v2: general discussion in Sec. IV expanded and improved, references added, other minor corrections throughout the text

References in corpus (1)

• Color superconductor with a color-sextet condensate

Cited by in corpus (6)

• Pion and Kaon Condensation at Finite Temperature and Density
• BCS-BEC crossover in dense relativistic matter: Collective excitations
• Goldstone bosons in presence of charge density
• Gluonic phases, vector condensates, and exotic hadrons in dense QCD
• Mesons and diquarks in neutral color superconducting quark matter with $\beta$-equilibrium
• Dynamical stabilization of runaway potentials and landscape of vacua at finite density