High Energy Theory Seminar

We show how to construct quiver-like (0,2) sigma models starting from few copies of (2,2) CP(N-1) models. These "quivers" present a natural generalization of the non-minimally deformed (2,2) model with an extra (0,2) fermion superfield on tangent bundle T CP(N-1)xC^{1} considered previously. Witten's index for this heterotically modified model vanishes,and spontaneous breaking of supersymmetry occurs.  Although the index vanishes in the quiver models as well a remarkable feature of the models is an absence of the spontaneous breaking of supersymmetry. We study supersymmetric vacua and determine the particle spectrum in the large-N limit. It is argued that (0,2) supersymmetry is not spontaneously broken even beyond the leading-N approximation. We then examine the exact beta functions of our quiver (0,2) sigma models and show that under certain conditions they develop an infrared fixed point in the perturbative domain.