Condensation of four-particle clusters: a soluble model

Abstract

Illustrates the gap type of equation for four-particle vertices discussed recently by means of a simple soluble model involving N (where N to infinity ) spin-1/2 fermions psi a(a=1,...,N) in 2+ epsilon space-time dimensions with the interaction -(1/2N)g0 mod psi TC psi mod 2 in the limit N to infinity . The model exhibits a condensate of four-particle clusters if the renormalised coupling constant g exceeds some critical value gc.