Field-Theoretical description of the crossover between BCS and BEC in a non-Fermi superconductor

Using the field-theoretical methods we studied the evolution from BCS description of a non-Fermi superconductor to that of Bose-Einstein condensation (BEC) in one loop approximation. We showed that the repulsive interaction between composite bosons is determined by the exponent $\alpha$ of the Anderson propagator in a two dimensional model. For $\text{a}\mathrm{\ne }0$ the crossover is also continous and for $\text{a}=0$ we obtain the case of the Fermi liquid.