Isoscalar Pairing and Pairs in Nuclei

International audienceThe question whether isoscalar pairing between neutrons and protons gives rise to correlationeffects similar to those observed for the isovector pairing between identical nucleons remainsunanswered. Some schematic properties of “ideal” isoscalar-pair condensates are pointed out.Isoscalar-pairing correlations can be probed with deuteron transfer reactions, which are thesubject of an experimental programme at GANIL. It is shown that simple predictions based on theassumption of a pair vibrational behaviour can assist in the interpretation of such experiments. Adifferent but related question is whether the low-energy structure of N~Z nuclei can be interpretedin terms of spin-aligned isoscalar pairs. This hypothesis can be tested, for example by measuringmagnetic and quadrupole moments of isomeric levels in odd-odd N=Z nuclei, such as for instance94Ag or 90Rh, which is one of the aims of the S3 project in preparation at GANIL