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Spontaneous symmetry breaking in the linear sigma model at finite chemical potential: One-loop corrections

Tomas Brauner
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Abstract

We investigate spontaneous symmetry breaking within the linear sigma model with the SU(2)xU(1) internal symmetry at finite chemical potential, which was suggested as a model for kaon condensation in the CFL phase of dense quark matter. One-loop corrections to the scalar field effective potential as well as its propagator are calculated. Particular attention is paid to the type-II Goldstone boson that appears in the Bose--Einstein condensed phase. Furthermore, we show that the type-I Goldstone boson -- the superfluid phonon -- is allowed to decay due to the nonlinearity of its dispersion relation at high momentum, and determine its decay width.

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Tomas Brauner. 2006-09-22. Spontaneous symmetry breaking in the linear sigma model at finite chemical potential: One-loop corrections. https://doi.org/10.1103/physrevd.74.085010

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