Quartetting in Nuclear Matter
  A general theory for the condensation of strongly bound quartets in infinite nuclear matter is presented. Critical temperatures for symmetric and asymmetric nuclear matter are evaluated. A fully nonlinear theory for the quartet order parameter, based on an analogy of the Gorkov approach to pairing, is presented and solved. The strong qualitative difference with pairing is pointed out. 
Peter Schuck, Takaaki Sogo, and Gerd R\"opke
nucl-th cond-mat.quant-gas