Unified BCS-Like Model of Pairing and Alpha-Correlations

We construct a BCS-like model that combines nucleonic pairing correlations and possible quartic correlations of alpha-type in a single variational wave function and derive corresponding gap equations. In the approximation of large logarithms typical for the BCS approach, we show that the system reveals two possible types of a condensate which cannot coexist. If the alpha-type condensate prevails at N = Z, the growth of the neutron excess will naturally lead to the first order phase transition to the nucleon condensates.