Nuclei: A superfluid condensate of particles? A study within the interacting-boson model

The authors have studied the question of whether pairs of neutrons and pairs of protons of the usual superfluid phases form a bound state to give rise to a superfluid condensate of " particles." They indeed find indications for this to be the case from a BCS-like study for bosons using the proton-neutron interacting-boson model as well as from an even-odd effect in the number of pairs using experimental binding energies.