Fragmentation of the Giant Pairing Vibration in ^{14}C Induced by Many-Body Processes

We present a theoretical framework for treating the full excitation spectrum of J^{π}=0^{+} pair addition modes, including the well-known low-lying and bound pairing vibrations on par with the predicted high-lying pairing vibrations, often called giant pairing vibrations. Our formalism includes the coupling to low-energy collective quadrupolar modes of the core, in such a way that both single-particle self-energy effects and the pairing interaction induced by phonon exchange are accounted for. The coupling with the continuum plays an important role and is also taken into account. The theory is applied to the case of the excitation spectrum of ^{14}C, recently populated by two-neutron transfer reactions.