Lattice baryon spectroscopy with multi-particle interpolators

Abstract

In 2 + 1 flavour lattice QCD the spectrum of the nucleon is presented for both parities using local meson-baryon type interpolating fields in addition to the standard three-quark nucleon interpolators. The role of local five-quark operators in extracting the nucleon excited state spectrum via correlation matrix techniques is explored on dynamical gauge fields with $m_{\pi }$ = 293 MeV, leading to the observation of a state consistent with the S-wave $N\pi$ scattering threshold in the negative-parity sector. Furthermore, the robustness of the variational technique is examined by studying the spectrum on a variety of operator bases. Fitting a single-state ansatz to the eigenstate-projected correlators provides robust energies for the low-lying spectrum that are essentially invariant despite being extracted from qualitatively different bases.

13 Pages, 12 Figures, Updated version as appears in PRD

References in corpus (4)

• A novel quark-field creation operator construction for hadronic physics in lattice QCD
• Chiral dynamics of the S11(1535) and S11(1650) resonances revisited
• Positive-parity Excited-states of the Nucleon in Quenched Lattice QCD
• Isolating the Roper Resonance in Lattice QCD

Cited by in corpus (3)

• Baryons as relativistic three-quark bound states
• Hamiltonian effective field theory study of the ${\mathbf{N}}^{\ast }(1440)$ resonance in lattice QCD
• Electromagnetic Form Factors of Excited Nucleons via Parity-Expanded Variational Analysis