We measure the spectrum of low-lying nucleon resonances using Bayesian fitting methods. We compare the masses obtained in the quenched approximation to those obtained with two flavours of dynamical fermions at a matched lattice spacing. At the pion masses employed in our simulations, we find that the mass of the first positive-parity nucleon excitation is always greater than that of the parity partner of the nucleon.
@article{arxiv.hep-lat/0209165,
title = {Excitations of the nucleon with dynamical fermions},
author = {UKQCD collaboration and C. M. Maynard and LHP collaboration and D. G. Richards},
journal= {arXiv preprint arXiv:hep-lat/0209165},
year = {2014}
}