Dibaryon Condensate in Nuclear Matter: Exact Analysis in One-Dimensional Models

Phase transitions of nuclear matter to the quark-gluon plasma with subsequent restoration of chiral symmetry have been widely discussed in the literature. We investigate the possibility for occurrence of dense nuclear matter with a dibaryon Bose-Einstein condensate as an intermediate state below the quark-gluon phase transition. An exact analysis of this state of matter is presented in a one-dimensional model. The analysis is based on a reduction of the quantization rules for theN-body problem toNcoupled algebraic transcendental equations. We observe that when the Fermi momentum approaches the resonance momentum, the one-particle distribution function increases near the Fermi surface. When the Fermi momen- tum is increased beyond the resonance momentum, the equation of state becomes softer. The observed behavior can be interpreted in terms of formation of a Bose-Einstein condensate of two-fermion resonances (e.g., dibaryons). In cold nuclear matter, it should occur at 2(m_N+ɛ_F)⩾m_Dwherem_Nandm_Dare the nucleon and dibaryon masses andɛ_Fis the nucleon Fermi energy.