Dynamical probes of pairing correlations: two-particle transfer and two-particle break-up reactions

We investigate the role played by pairing correlations in two typical classes of nuclear reactions specifically involving pairs of particles: two-particle transfer reactions, where a pair of nucleons is exchanged between the reaction partners, and two-particle break-up reactions, where a pair of nucleons is emitted. In both cases we find that, although the process is mainly induced by the repeated action on each particle by the one-body field created by the reaction partner, a coherent enhancing effect is generated by the pair correlation present in the initial wave function, acting during the process and again present (in the case of two-particle transfer) in the final wave function. In the case of reactions involving weakly-bound nuclei the low-density features characterizing the vicinity of the drip line and the suggested consequent enhancement of the pairing correlations should show up as clear signature in both processes. From the point of view of their theoretical description, the vicinity of the drip lines will involve heavily the continuum part of the spectrum and we will test in simple models the validity of different discretization procedures used in the description of both structure and reaction.