STRONG-COUPLING ANALYSIS OF THE LATTICE CPN-1 MODELS IN THE PRESENCE OF A THETA-TERM

A theta term, which couples to topological charge, is added to the lat tice CPN-1 model. The strong-coupling character expansion is developed . The series for the free energy and mass gap are, respectively, compu ted to tenth order and fourth order. Several features of the strong-co upling analysis emerge. One is the loss of superconfinement. Another i s that, in the intermediate coupling constant region, there are indica tions of a transition to a deconfining phase when theta is sufficientl y large. The transition is like the one which has been observed in Mon te Carlo simulations of a similar lattice CPN-1 action.