Abstract:

The BEC-BCS crossover has been realized in cold fermion gases with the aid of Feshbach resonances. The effect of interactions, e.g., the mean field and pairing, has been probed experimentally by radio-frequency spectroscopy, which measures the spin correlation of the system. However, the symmetry of the system imposes constraints on the spin correlation functions through sum rules.  I conduct a self-consistent calculation of the spin correlation functions within the Hartree-Fock-BCS theory. Our result reproduces the mean field shift and pairing signal observed in the experiments.