Nucleon Excited States in N$_f$=2 lattice QCD

TL;DR

This study explores nucleon excited states using lattice QCD with twisted mass and Clover fermions, analyzing variational methods to identify low-lying positive and negative parity states.

Contribution

It introduces a comparative analysis of variational bases in lattice QCD to extract nucleon excited states at near-physical pion masses.

Findings

Identification of the two lowest positive parity states.

Identification of the two lowest negative parity states.

Analysis of variational basis effectiveness.

Abstract

We investigate the excited states of the nucleon using $N_f=2$ twisted mass gauge configurations with pion masses in the range of about 270 MeV to 450 MeV and one ensemble of $N_f=2$ Clover fermions at almost physical pion mass. We use two different sets of variational bases and study the resulting generalized eigenvalue problem. We present results for the two lowest positive and negative parity states.