Resurrection of a Symmetry in Nucleon-Nucleus Scattering

Abstract
We reexamine a symmetry in nucleon-nucleus scattering that previously had been proclaimed to be dead. We show that this symmetry is the continuum analog of pseudospin symmetry, a relativistic symmetry which manifests itself in the spectra of nuclei. Using experimental data only, we show that pseudospin symmetry in nucleon-nucleus scattering is not dead but only modestly broken for 800 MeV proton scattering on nuclei.