Hybrid Baryons in QCD

TL;DR

This study uses lattice QCD to identify and analyze hybrid baryons, revealing a spectrum of states with gluonic excitations that are consistent with a common color octet gluonic excitation pattern.

Contribution

First comprehensive lattice QCD analysis of hybrid baryons, identifying their spectrum and gluonic excitation characteristics.

Findings

Identified hybrid baryon states with specific quantum numbers.

Found energy scale of hybrid excitations above conventional baryons.

Observed compatibility with gluonic excitation patterns in hybrid mesons.

Abstract

We present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbers N_1/2+, N_1/2+, N_3/2+, N_3/2+, N_5/2+ and Delta_1/2+, Delta_3/2+ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible with a color octet gluonic excitation having J^P=1+ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.