Low-lying baryon resonances from lattice QCD

Abstract

Recent results studying the masses and widths of low-lying baryon resonances in lattice QCD are presented. The $S$-wave $N\pi$ scattering lengths for both total isospins $I=1/2$ and $I=3/2$ are inferred from the finite-volume spectrum below the inelastic threshold together with the $I=3/2$ $P$-wave containing the $\Delta (1232)$ resonance. A lattice QCD computation employing a combined basis of three-quark and meson-baryon interpolating operators with definite momentum to determine the coupled channel $\Sigma \pi$-$N\overline{K}$ scattering amplitude in the $\Lambda (1405)$ region is also presented. Our results support the picture of a two-pole structure suggested by theoretical approaches based on $SU(3)$ chiral symmetry and unitarity.

Comments: 5 pages, 3 figures, talk presented at the 20th International Conference on Hadron Spectroscopy and Structure (HADRON 2023) in Genova, Italy, June 5th to 9th 2023