Dynamical nature of the nuclear pseudospin and its isospin asymmetry

Abstract

Pseudospin symmetry in nuclei is investigated by solving the Dirac equation with Woods-Saxon scalar and vector radial potentials. We relate the pseudospin interaction with a pseudospin-orbit term in a Schroedinger-like equation for the lower component of the Dirac spinor. We show that this term gives a large contribution to the energy splittings of pseudospin partners, so that the near pseudospin degeneracy arises from a significant cancellation among the different terms in that equation. This is a manifestation of the dynamical character of this symmetry in the nucleus. We analyze the isospin dependence of the pseudospin symmetry in a nuclear isotope chain by including a vector-isovector potential V_rho and a Coulomb potential and conclude that V_rho gives the main contribution to the observed pseudospin isospin asymmetry.

4 pages, 2 figures, uses World Scientific style file. Contribution presented at the VIII International Workshop on Hadron Physics, Bento Goncalves, RS, Brazil, April 14-19, 2002. To be published by World Scientific in the proceedings of the "International Workshop on Hadron Physics 2002"