Gauge symmetry enhancement in the Hamiltonian formalism

Abstract

We study the Hamiltonian structure of the gauge symmetry enhancement in the enlarged CP(N) model coupled with a U(2) Chern-Simons term, which contains a free parameter governing explicit symmetry breaking and symmetry enhancement. After giving a general discussion of the geometry of constrained phase space suitable for the enhancement, we explicitly perform the Dirac analysis of our model and compute the Dirac brackets for the symmetry enhanced and broken cases. We also discuss some related issues. © 2003 The American Physical Society.