Baryon resonances coupled to Pion-Nucleon states in lattice QCD

TL;DR

This paper investigates baryon resonances decaying into pion-nucleon states using lattice QCD, focusing on the nucleon spectrum and addressing computational challenges in multi-particle systems.

Contribution

It introduces a method to study baryon resonances and pion-nucleon interactions on the lattice, including explicit Wick contraction calculations and symmetry considerations.

Findings

Correlation functions for single and multi-particle states computed.

Results for $n_f=2$ light quark masses presented.

Analysis of symmetry effects in moving frames.

Abstract

In recent years the study of two particle systems on the lattice has led to excellent results in the meson sector of the QCD spectrum, however baryon resonances mostly remain unexplored. We present a study of pion-nucleon systems as decay product of baryon resonances in different channels, with special focus on the nucleon spectrum. We evaluate the correlation functions of single and multi particle interpolators. All the Wick contributions are explicitly computed and the consequences of reduced symmetries in moving frames are taken into account. We discuss the theoretical setup together with results for $n_f=2$ mass degenerate light quarks.