Speaker
Description
In a relativistic quantum field theory like Quantum Chromodynamics (QCD), there is no upper bound on the spin of a hadron. Baryon resonances have been experimentally confirmed for the Nucleon and ∆ baryons up to spin Jᴾ = 15/2⁺ range with varying certainty. Of the higher-spin baryons, generally meaning baryons with J > 3/2, only a select few have been treated using functional methods such as Bethe-Salpeter equations (BSE) – in part, because these calculations quickly escalate in complexity in the three-body picture of the baryon. The diquark picture, which views baryons as quark-diquark bound states, on the other hand, provides an interesting venue to study higher-spin resonances, where most of these complications are absent. In this approach the bound-state equation for the diquark takes, apart from its color structure, the same shape as the meson BSE. The resulting diquark Bethe-Salpeter-amplitude is combined with the remaining quark and diquark ingredients in a rainbow-ladder truncation into a quark-diquark BSE, which is solved by converting it to an eigenvalue problem.
The corresponding spectrum of light, spin J = 1/2 and 3/2 baryons has been extensively studied in the past. As an extension of these considerations, this talk focuses on the expansion of the light quark-diquark baryon spectrum into the higher-spin regime.