Higgs and Coulomb/confining phases in "twisted-mass" deformed CP(N-1) model

We consider nonsupersymmetric two-dimensional CP(N-1) model deformed by a term presenting the bosonic part of the twisted-mass deformation of N=2 supersymmetric version of the model. Our deformation has a special form preserving a ZN symmetry at the Lagrangian level. In the large mass limit the model is weakly coupled. Its dynamics is described by the Higgs phase, with ZN spontaneously broken. At small masses it is in the strong coupling Coulomb/confining phase. The ZN symmetry is restored. Two phases are separated by a phase transition. We find the phase transition point in the large-N limit. It lies at strong coupling. As was expected, the phase transition is related to broken versus unbroken ZN symmetry in these two respective phases. The vacuum energies for these phases are determined too.