2003/01/24 by Thomas D. Cohen, Richard F. Lebed, Richard. F. Lebed · 51 citations
Physics and Astronomy · #Baryon #Context (archaeology) #Coupling (piping) #Excited state #High-Energy Particle Collisions Research #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quark #hep-ph
paper · pdf · doi:10.1103/physrevd.67.096008
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 67(9) (American Physical Society) · 13 pages, ReVTeX4
arxiv created 2003/01/24 · openalex publication_date 2003/05/29 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze excited baryon properties via a 1/Nc expansion from two perspectives: as resonances in meson-nucleon scattering, and as single-quark excitations in the context of a simple quark model. For both types of analysis one can derive novel patterns of degeneracy that emerge as Nc\ensuremath→\ensuremath∞, and that are shown to be compatible with one another. This helps justify the single-quark excitation picture and may give some insight into its successes. We also find that in the large Nc limit one of the S11 baryons does not couple to the \ensuremathπ\ensuremath-N channel but couples to the \ensuremathη\ensuremath-N channel. This is empirically observed in the N(1535), which couples very weakly to the \ensuremathπ\ensuremath-N channel and quite strongly to the \ensuremathη\ensuremath-N channel. The comparatively strong coupling of the N(1650) to the \ensuremathπ\ensuremath-N channel and weak coupling to \ensuremathη\ensuremath-N channel is also predicted. In the context of the simple quark model picture we reproduce expressions for mixing angles that are accurate up to O(1/Nc) corrections and are in good agreement with mixing angles extracted phenomenologically.