The classical pion field in a nucleus
arXiv:0711.1280 · doi:10.1016/j.nuclphysa.2008.10.004
Abstract
A self-consistent symmetry arises when the nucleon angular momentum j and the isospin t are coupled to a grand spin G. Closed G shells become sources of a classical pion field with a hedgehog shape. Although the amplitude of the pion field, as measured by the chiral angle, is small, it is found to perturb significantly the energies of the nucleon orbits.
17 pages, 3 figures, new appendix, revised conclusions