Broken Symmetry in Nuclear Matter

The stability of uniform nuclear matter is investigated by optimizing the energy of a broken-symmetry state having a periodic density wave. The instability is a finite amplitude one. It does not occur until the amplitude is large, and it requires also a severe distortion of the Fermi surface. The binding energy is increased by 1.5 MeV per nucleon. Additionally, an infinite slab of nuclear matter, 12 fm thick, is found to have an extra binding energy of 0.9 MeV, which implies that the surface energy changes sign when the surface curvature becomes small.