Wigner symmetry, large Nc, and renormalized one-boson exchange potentials

Wigner symmetry in nuclear physics provides a unique example of a nonperturbative medium and long distance symmetry, a symmetry strongly broken at short distances. We analyze the consequences of such a concept within the framework of one-boson exchange potentials in NN scattering and keeping the leading Nc contributions. Phenomenologically successful relations between singlet 1S0 and triplet 3S1 scattering phase shifts are provided in the entire elastic region. We establish symmetry breaking relations among noncentral phase shifts which are successfully fulfilled by even-L partial waves and strongly violated by odd-L partial waves, in full agreement with large Nc requirements