Structure of Matter below Nuclear Saturation Density

Abstract

It is found that just below nuclear saturation density more stable forms of dense matter exist than the near-spherical nuclei or bubbles customarily assumed. Because of the large effect of the Coulomb lattice energy, cylindrical and planar geometries can occur, both as nuclei and as bubbles. It is suggested that in order to approximate more complicated kinds of short-range order, the dimensionality should be regarded as a continuous variable ranging from $d=3$ (spheres) to $d=1$ (planes). The dependence of $d$ on density is illustrated, and its dependence on nuclear models discussed.