Excited nucleon spectrum with two flavors of dynamical fermions

TL;DR

This study calculates the excited nucleon spectrum using lattice QCD with dynamical fermions, employing optimized operators and the variational method to identify multiple excited states and their spins.

Contribution

It introduces a method to extract excited nucleon states with dynamical fermions using optimized operators and the variational approach on anisotropic lattices.

Findings

Multiple excited states identified for each irrep.

Continuum spin assignment for lowest-lying states including J^P=5/2^-.

Successful extraction of excited nucleon spectrum with dynamical fermions.

Abstract

We compute the spectrum of excited nucleons using the anisotropic Wilson lattice with two flavors of dynamical fermions. Using optimized sets of operators which transform irreducibly under the octahedral group, matrices of correlation functions are computed. We apply the variational method to these matrices to extract excited energy eigenstates. We obtain several states for each irrep and identify the continuum spin for the lowest-lying states, including a $J^P={5/2}^-$ state.