Spin and Resonant States in QCD

Abstract

I make the case that the nucleon excitations do not exist as isolated higher spin states but are fully absorbed by (K/2,K/2)*[(1/2,0)+ (0,1/2)] multiplets taking their origin from the rotational and vibrational excitations of an underlying quark--diquark string. The Δ(1232) spectrum presents itself as the exact replica (up to Δ(1600)) of the nucleon spectrum with the K- clusters being shifted upward by about 200 MeV. QCD inspired arguments support legitimacy of the quark-diquark string. The above K multiplets can be mapped (up to form-factors) onto Lorentz group representation spaces of the type ψ_μ_1...μ_K, thus guaranteeing covariant description of resonant states. The quantum ψ_μ_1...μ_K states are of multiple spins at rest, and of undetermined spins elsewhere.

Added Ref. M. Kirchbach, D.V. Ahluwlalia, Phys. Lett. B529, 131 (2002) as the source of Figure 1. No further changes