The stability of nuclear matter in the Nambu–Jona-Lasinio model Original Research Article

Using the Nambu–Jona-Lasinio model to describe the nucleon as a quark–diquark state, we discuss the stability of nuclear matter in a hybrid model for the ground state at finite nucleon density. It is shown that a simple extension of the model to simulate the effects of confinement leads to a scalar polarizability of the nucleon. This, in turn, leads to a less attractive effective interaction between the nucleons, helping to achieve saturation of the nuclear matter ground state. It is also pointed out that that the same effect naturally leads to a suppression of “Z-graph” contributions with increasing scalar potential.