Pairing and alpha-like quartet condensation in N=Z nuclei
  We discuss the treatment of isovector pairing by an alpha-like quartet condensate which conserves exactly the particle number, the spin and the isospin. The results show that the quartet condensate describes accurately the isovector pairing correlations in the ground state of systems with an equal number of protons and neutrons 
N. Sandulescu, J. Dukelsky, D. Negrea
nucl-th