Spontaneously broken ground states of the U(n)_L x U(n)_R linear sigma model at large n

Abstract

Symmetry breaking patterns of the U(n)_L x U(n)_R symmetric meson model are investigated in a formulation involving three auxiliary composite fields. The effective potential is constructed at leading order in the 1/n expansion for a condensate belonging to the center of the U(n) group. A wide region is found in the coupling space where in addition to the condensate proportional to the unit matrix, also metastable minima exist, in which a further breakdown of the diagonal U_V(n) symmetry to U_V(n-1) is realized. Application of a moderate external field conjugate to this component of the order parameter changes this state into the true ground state of the system.

ReVTeX4, 10 pages, 5 figures. Extended introduction and conclusion. Version published in Phys. Rev. D

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Cited by in corpus (3)

• Invariant formulation of the Functional Renormalisation Group method for $U(n)\times U(n)$ symmetric matrix models
• Chiral symmetry breaking patterns in the U_L(n)xU_R(n) meson model
• Finite temperature symmetry restoration in the U_L(3)xU_R(3) linear sigma model from a large-n approximation