Highly excited negative parity baryons in the $1/N_c$ expansion

TL;DR

This paper calculates the masses of highly excited negative parity baryons using the $1/N_c$ expansion, revealing dominant contributions from flavor and spin operators to SU(6) symmetry breaking.

Contribution

It introduces a procedure that reduces the number of operators in the mass formula, providing a more efficient analysis of excited baryons in the $1/N_c$ framework.

Findings

Large, comparable coefficients for flavor and spin operators.

Dominant contribution of these operators to SU(6) symmetry breaking.

Consistent results with known multiplet structures.

Abstract

The masses of experimentally known highly excited baryons of negative parity supposed to belong to the $[{\bf 70},\ell^-]$ multiplets ($\ell$ = 1,2,3) of the $N = 3$ band are calculated in the $1/N_c$ expansion method to order $1/N_c$ by using a procedure which allows to considerably reduce the number of linearly independent operators entering the mass formula. The numerical fits to present data show that the coefficients encoding the QCD dynamics have large, comparable values, for the flavor and spin operators. It implies that these operators contribute dominantly to the flavor-spin SU(6) symmetry breaking, like for the $[{\bf 70},1^-]$ multiplet of the $N = 1$ band.