Scattering of light and atoms in a Fermi-Dirac gas with Bardeen-Cooper-Schrieffer pairing - art. no. 033605

We theoretically study the optical properties of a Fermi-Dirac gas in the p resence of a superfluid state. We calculate the leading quantum-statistical corrections to the standard column density result of the electric suscepti bility. We also consider the Bragg diffraction of;atoms by means of Light-s timulated transitions of photons between two intersecting laser beams. Bard een-Cooper-Schrieffer pairing between atoms in different internal levels ma gnifies incoherent scattering processes. The absorption linewidth of a Ferm i-Dirac gas is broadened and shifted. Bardeen-Cooper-Schrieffer pairing int roduces a collisional local-field shift that may dramatically dominate the Lorentz-Lorenz shift. For the case of the Bragg spectroscopy the static str ucture function may be significantly increased due to superfluidity in the near-forward scattering.