BCS-BEC crossover in relativistic Fermi systems

Abstract

We review the BCS-BEC crossover in relativistic Fermi systems, including the QCD matter at finite density. In the first part we study the BCS-BEC crossover in a relativistic four-fermion interaction model and show how the relativistic effect affects the BCS-BEC crossover. In the second part, we investigate both two-color QCD at finite baryon density and pion superfluid at finite isospin density, by using an effective Nambu--Jona-Lasinio model. We will show how the model describes the weakly interacting diquark and pion condensates at low density and the BEC-BCS crossover at high density.

Comments: 44 Pages, 20 figures, accepted by International Journal of Modern Physics A. arXiv admin note: substantial text overlap with arXiv:1007.1920, arXiv:1202.3490, arXiv:hep-ph/0703042