Alternate 1/N_c Expansions and SU(3) Breaking from Baryon Lattice Results

TL;DR

This paper demonstrates that combined 1/N_c and SU(3) breaking expansions accurately describe baryon mass spectra, confirming previous results across different quark representations and lattice simulation variations.

Contribution

It extends the validity of baryon mass relations to antisymmetric quark representations and alternative baryon identification methods within the large N_c framework.

Findings

Mass relations hold for antisymmetric quarks.

Lattice simulations confirm robustness of 1/N_c relations.

Results are consistent across different baryon identification schemes.

Abstract

A combined expansion in the number of QCD colors 1/N_c and SU(3) flavor breaking parameter epsilon has long been known to provide an excellent accounting for the mass spectrum of the lightest spin-1/2, 3/2 baryons when the quarks are taken to transform under the fundamental SU(N_c) representation, and in the final step N_c \to 3 and epsilon is set to its physical value ~0.3. Subsequent work shows that placing quarks in the two-index antisymmetric SU(N_c) representation leads to quantitatively equally successful mass relations. Recent lattice simulations allow for varying the value of epsilon and confirm the robustness of the original 1/N_c relations. In this paper we show that the same conclusion holds for the antisymmetric quarks, and demonstrate that the mass relations also hold under alternate prescriptions for identifying physical baryons with particular members of the large N_c multiplets.