Evidence for a spin-quartet of nucleon resonances at 2 GeV

Results from a multichannel partial wave analysis of elastic and inelastic πN and γN   induced reactions are presented. The analysis evidences the existence of a spin-quartet of nucleon resonances with total angular momenta J^P=1/2⁺,…,7/2⁺$J^P=1/2^{+},\dots ,7/2^{+}$. All states fall into a ±130 MeV mass gap centered at 1.97 GeV. The spin quartet is at variance with S-wave diquark configurations required in classical diquark models.