Correlations and Pairing in Nuclear

The innuence of correlations on the critical temperature and density for the onset of superruidity in nuclear matter is investigated within the scheme of Nozi eres and Schmitt-Rink 1]. For symmetric nuclear matter a smooth transition from Bose-Einstein condensation (BEC) of deuteron-like bound states at low densities and low temperatures to Bardeen-Cooper-Schrieeer (BCS) pair-ing at higher densities is described. Compared with the mean eld approach a lowering of the critical temperature is obtained for symmetric nuclear matter as well as for pure neutron matter. The Mott transition in symmetric nuclear matter is discussed. Regions in the temperature{density plane are identiied where correlated pairs give the main contribution to the composition of the system, so that approximations beyond the quasi-particle picture are requested.