Large-$N$ Solution and Effective Action of "Twisted-Mass'' Deformed $\mathbb{CP}(N-1)$ Model

Abstract

We study effective dynamics of the non-supersymmetric two-dimensional $\mathbb{CP}(N-1)$ model in the large $N$ limit. This model is deformed by a mass term $m$ preserving $\mathbb{Z}_N$ symmetry of the Lagrangian. At small $m$ the theory is strongly coupled and resembles the undeformed $\mathbb{CP}(N-1)$ model, while at large $m$ it is in a weakly coupled Higgs phase with spontaneously broken $\mathbb{Z}_N$. We find the phase transition point and discuss the fate of the kink-antikink ``mesons'' at strong coupling. We also resolve an issue of instability that arose in previous studies of this model.