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Title: Restoration of QCD classical symmetries in excited hadrons

Abstract

Restoration of chiral and U(1)A symmetries in excited hadrons is reviewed. A connection of these restorations with the semiclassical regime in highly excited hadron is discussed. A solvable confining field-theoretical toy model that exhibits chiral restoration is presented. Implications of the string description of the highly excited hadrons that suggests an additional dynamical symmetry of the spectra on the top of U(2)L U(2)R are presented.

Authors:
 [1]
  1. Institute for physics/Theoretical physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria)
Publication Date:
OSTI Identifier:
21056859
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714344; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BARYON SPECTROSCOPY; CHIRAL SYMMETRY; CHIRALITY; EXCITED STATES; HADRONS; MESON SPECTROSCOPY; QUANTUM CHROMODYNAMICS; SEMICLASSICAL APPROXIMATION; U-1 GROUPS; U-2 GROUPS; UNITARY SYMMETRY

Citation Formats

Glozman, L. Ya. Restoration of QCD classical symmetries in excited hadrons. United States: N. p., 2007. Web. doi:10.1063/1.2714344.
Glozman, L. Ya. Restoration of QCD classical symmetries in excited hadrons. United States. doi:10.1063/1.2714344.
Glozman, L. Ya. Tue . "Restoration of QCD classical symmetries in excited hadrons". United States. doi:10.1063/1.2714344.
@article{osti_21056859,
title = {Restoration of QCD classical symmetries in excited hadrons},
author = {Glozman, L. Ya.},
abstractNote = {Restoration of chiral and U(1)A symmetries in excited hadrons is reviewed. A connection of these restorations with the semiclassical regime in highly excited hadron is discussed. A solvable confining field-theoretical toy model that exhibits chiral restoration is presented. Implications of the string description of the highly excited hadrons that suggests an additional dynamical symmetry of the spectra on the top of U(2)L U(2)R are presented.},
doi = {10.1063/1.2714344},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}
  • In this paper, we discuss the transition to the semiclassical regime in excited hadrons, and consequently, the restoration of chiral symmetry for these states. We use a generalized Nambu-Jona-Lasinio model with the interaction between quarks in the form of the instantaneous Lorentz-vector confining potential. This model is known to provide spontaneous breaking of chiral symmetry in the vacuum via the standard self-energy loops for valence quarks. It has been shown recently that the effective single-quark potential is of the Lorentz-scalar nature, for the low-lying hadrons, while, for the high-lying states, it becomes a pure Lorentz vector and hence the modelmore » exhibits the restoration of chiral symmetry. We demonstrate explicitly the quantum nature of chiral symmetry breaking, the absence of chiral symmetry breaking in the classical limit, as well as the transition to the semiclassical regime for excited states, where the effect of chiral symmetry breaking becomes only a small correction to the classical contributions.« less
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