Masses of positive and negative parity excited nucleons and hyperons are calculated in quenched lattice QCD using an O(a^2) improved gluon action and a fat-link clover fermion action in which only the irrelevant operators are constructed with fat links. The results are in agreement with earlier N* simulations with improved actions, and exhibit a clear mass splitting between the nucleon and its parity partner, as well as a small mass splitting between the two low-lying J^P={1/2}^- N* states. Study of different Lambda interpolating fields suggests a similar splitting between the lowest two {1/2}^- Lambda* states, although the empirical mass suppression of the Lambda*(1405) is not seen.
@article{arxiv.hep-lat/0210042,
title = {Excited Baryons from the FLIC Fermion Action},
author = {W. Melnitchouk and J. N. Hedditch and D. B. Leinweber and A. G. Williams and J. M. Zanotti and J. B. Zhang},
journal= {arXiv preprint arXiv:hep-lat/0210042},
year = {2010}
}
Comments
3 pages, 3 figures, Lattice2002(QCD Spectrum and Quark Masses)