Emergence of a newSU(4)symmetry in the baryon spectrum

M. Denissenya, ∗ L. Ya. Glozman, † and M. Pak ‡ Institut fur Physik, FB Theoretische Physik, Universitat Graz, Universitatsplatz 5, 8010 Graz, Austria Recently a large degeneracy of J = 1 mesons, that is larger than the SU(2)L × SU(2)R × U(1)A symmetry of the QCD Lagrangian, has been discovered upon truncation of the near-zero modes from the valence quark propagators. It has been found that this degeneracy represents the SU(4) group that includes the chiral rotations as well as the mixing of leftand right-handed quarks. This symmetry group turnes out to be a symmetry of confinement in QCD. Consequently, one expects that the same symmetry should persist upon the near-zero mode removal in other hadron sectors as well. It has been shown that indeed the J = 2 mesons follow the same symmetry pattern upon the low-lying mode elimination. Here we demonstrate the SU(4) symmetry of baryons once the near-zero modes are removed from the quark propagators. We also show a degeneracy of states belonging to different irreducible representations of SU(4). This implies a larger symmetry, that includes SU(4) as a subgroup.