INSTABILITY OF INFINITE NUCLEAR-MATTER IN THE SIGMA-OMEGA MODEL

We demonstrate that, within the relativistic σ-ω model, the uniform mean-field solution for infinite nuclear matter is unstable for certain values of the scalar mass. For scalar masses greater than about 690 MeV, there is a state of nuclear matter which has a spatially periodic density and is lower in energy than the uniform state. We also demonstrate that the periodic state of nuclear matter has a lower compressibility than the uniform state, and that the density of the periodic state can be interpreted in terms of alpha-particle clustering. Furthermore, the secondary effects of the instability of nuclear matter can be seen in relativistic calculations of finite nuclei and similar effects are present in electron scattering data. © 1990 The American Physical Society.