In-beam study of105In and103In

The effects on pair density fluctuations in superfluid nuclei, associated with the projection on good particle number, are studied. The model, which is based on standard particle number projection techniques, is developed for the case of one and two-body density fluctuations in spherical superfluid nuclei. The results, for the case of some even mass isotopes of Sn, show that pair density fluctuations and the derivative of the one body density almost coincide in a number projected BCS treatment of pairing correlations.