Pairing correlations and transitions in nuclear systems

Abstract

We discuss several pairing-related phenomena in nuclear systems, ranging from superfluidity in neutron stars to the gradual breaking of pairs in finite nuclei. We describe recent experimental evidence that points to a relation between pairing and phase transitions (or transformations) in finite nuclear systems. A simple pairing interaction model is used in order to study and classify an eventual pairing phase transition in finite fermionic systems such as nuclei. We show that systems with as few as ∼ 10−16 fermions can exhibit clear features reminiscent of a phase transition.

Pairing correlations and thermodynamical quantities inMo96,97

“…The two residual interactions in nuclear physics are shortrange or pairing [7,8] and long-range or quadrupole. The energy gap in the spectra of even-even nuclei and odd-even effect observed in the nuclear masses are manifestation of pairing effect in nuclei.…”