Two Nucleon-States in a Chiral Quark-Diquark Model
High Energy Physics - Phenomenology
2009-11-11 v2
Abstract
We study the ground and first excited states of nucleons in a chiral quark-diquark model. We include two quark-diquark channels of the scalar-isoscalar and axial-vector-isovector types for the nucleon states. The diquark correlation violating the spin-flavor SU(4) symmetry allows to treat the two quark-diquark channels independently. Hence the two states appear as the superpositions of the two quark-diquark channels; one is the nucleon and the other is a state which does not appear in the SU(4) quark models. With a reasonable choice of model parameters, the mass of the excited state appears at around 1.5 GeV, which we identify with the Roper resonance N(1440).
Cite
@article{arxiv.hep-ph/0506193,
title = {Two Nucleon-States in a Chiral Quark-Diquark Model},
author = {Keitaro Nagata and Atsushi Hosaka},
journal= {arXiv preprint arXiv:hep-ph/0506193},
year = {2009}
}
Comments
11 pages, 5 figures. Errors are corrected. Conclusions are not affected