Pairing in low-density Fermi gases

We consider pairing in a dilute system of fermions with a short-range inter action. While the theory is ill-defined for a contact interaction, the BCS equations can be solved in the leading order of low-energy effective held t heory. The integrals are evaluated with the dimensional regularization tech nique. giving analytic formulas relating the pairing gap, the density, and the energy density to the two-particle scattering length. [S0556-2813(99)04 804-9].