Regge trajectories of excited baryons, quark-diquark models, and quark-hadron duality

Abstract

The parton model relations in conjunction with quark-hadron duality in deep inelastic scattering suggests an asymptotic dominance of quark-diquark type of baryonic excited states with a radial Regge uniformly distributed mass squared spectrum $M_{n}^2 = \mu^2 n + M_0^2$. We argue that this points to a lineary quark-diquark confining potential. We analyze the radial ($n$) and angular-momentum ($J$) Regge trajectories for all light-quark states with baryon number one listed in the 2016 edition of the Particle Data Tables. The parameters of the mass squared trajectories are obtained by linear regression assuming $\Delta M_n^2 \sim M_n \Gamma_n $ weighted with the width $\Gamma_n$ of the resonance and the error analysis is carried out accordingly.