QCD symmetries in excited hadrons
Abstract
Recent developments for chiral and restorations in excited hadrons are reviewed. We emphasize predictions of the chiral symmetry restoration scenario for axial charges and couplings to Goldstone bosons. Using very general chiral symmetry arguments it is shown that strict chiral restoration in a given excited nucleon forbids its decay into the channel. We confront this prediction with the coupling constants extracted from the decay widths and observe a 100 % correlation of these data with the spectroscopic parity doublet patterns. These results suggest that the lowest approximate chiral parity doublet is the pair. In the meson sector we discuss predictions of the chiral symmetry restoration for still missing states and a signature of the higher symmetry observed in new data. We conclude with the exactly solvable chirally symmetric and confining model that can be considered as a generalization of the 1+1 dimensional 't Hooft model to 4 dimensions. Complete spectra of mesons demonstrate a fast chiral restoration with increasing and a slow one with increasing .
Cite
@article{arxiv.0710.0978,
title = {QCD symmetries in excited hadrons},
author = {L. Ya. Glozman},
journal= {arXiv preprint arXiv:0710.0978},
year = {2008}
}
Comments
10 pp, Invited talk at MENU 2007, September 10 - 14, 2007, Juelich, Germany