SU suN) gauge theories with C-periodic boundary conditions (II). Small-volume dynamics

The dynamics of SU( N) gauge theories, especially for N = 3, in a small C-periodic box are investigated. We identify the field that minimize the energy - the torons - and determine which of these "classical" vacua are stable quantum mechanically. The stable torons break cubic symmetry, which has interesting consequences on the spectrum. At any of the stable torons there are also quartic modes. Since all C-periodic boundary conditions are gauge-equivalent, we choose a convenient version, for which the quartic modes are constant modes, and compute the effective hamiltonian to one loop in perturbation theory.