Nucleon scattering from lattice QCD

Abstract

Recent results from lattice QCD on baryon resonances and meson-baryon, baryon-baryon scattering are presented. Such scattering processes and resonances can be determined in lattice QCD by first obtaining the finite-volume energy spectrum of stationary states involving meson-baryon and baryon-baryon systems. A well-known quantization condition involving the scattering $K$-matrix and a complicated ``box matrix'' also yields a finite-volume energy spectrum. By appropriately parametrizing the scattering $K$-matrix, the best fit values of the $K$-matrix parameters are those which produce a finite-volume spectrum which best matches that obtained from lattice QCD. The $\Delta$ resonance, a recent study of the two-pole nature of scattering near the $\Lambda(1405)$, and $NN$ scattering in the $SU(3)$ flavor limit are highlighted.