skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Strong decays of excited baryons in Large Nc QCD

Abstract

We present the analysis of the strong decays widths of excited baryons in the framework of the 1/Nc expansion of QCD. These studies are performed up to order 1/Nc and include both positive and negative parity excited baryons.

Authors:
 [1];  [2];  [3];  [4];  [4]
  1. Physics Dept., Hampton University, Hampton, VA 23668 (United States)
  2. (United States)
  3. Lab. TANDAR, CNEA, Av.Libertador 8250, 1429 Buenos Aires (Argentina)
  4. (Argentina)
Publication Date:
OSTI Identifier:
21054883
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 884; Journal Issue: 1; Conference: 6. Latin American symposium on nuclear physics and applications, Iguazu (Argentina), 3-7 Oct 2005; Other Information: DOI: 10.1063/1.2710649; (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; BARYONS; EXCITED STATES; GAUGE INVARIANCE; HADRONIC PARTICLE DECAY; PARITY; PARTICLE WIDTHS; QUANTUM CHROMODYNAMICS

Citation Formats

Goity, J. L., TJNAF, Newport News, VA 23606, Scoccola, N. N., CONICET, Rivadavia 1917, 1033 Buenos Aires, and Universidad Favaloro, Solis 453, 1078 Buenos Aires. Strong decays of excited baryons in Large Nc QCD. United States: N. p., 2007. Web. doi:10.1063/1.2710649.
Goity, J. L., TJNAF, Newport News, VA 23606, Scoccola, N. N., CONICET, Rivadavia 1917, 1033 Buenos Aires, & Universidad Favaloro, Solis 453, 1078 Buenos Aires. Strong decays of excited baryons in Large Nc QCD. United States. doi:10.1063/1.2710649.
Goity, J. L., TJNAF, Newport News, VA 23606, Scoccola, N. N., CONICET, Rivadavia 1917, 1033 Buenos Aires, and Universidad Favaloro, Solis 453, 1078 Buenos Aires. Mon . "Strong decays of excited baryons in Large Nc QCD". United States. doi:10.1063/1.2710649.
@article{osti_21054883,
title = {Strong decays of excited baryons in Large Nc QCD},
author = {Goity, J. L. and TJNAF, Newport News, VA 23606 and Scoccola, N. N. and CONICET, Rivadavia 1917, 1033 Buenos Aires and Universidad Favaloro, Solis 453, 1078 Buenos Aires},
abstractNote = {We present the analysis of the strong decays widths of excited baryons in the framework of the 1/Nc expansion of QCD. These studies are performed up to order 1/Nc and include both positive and negative parity excited baryons.},
doi = {10.1063/1.2710649},
journal = {AIP Conference Proceedings},
number = 1,
volume = 884,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}
  • We present the analysis of the strong decays widths of excited baryons in the framework of the 1/Nc expansion of QCD. These studies are performed up to order 1/Nc and include both positive and negative parity excited baryons.
  • We use the 1/Nc expansion of QCD to analyse the spectrum of positive parity resonances with strangeness S = 0, -1, -2 and -3 in the 2-3 GeV mass region, supposed to belong to the [56,4+] multiplet. The mass operator is similar to that of [56,2+], previously studied in the literature. The analysis of the latter is revisited. In the [56,4+] multiplet we find that the spin-spin term brings the dominant contribution and that the spin-orbit term is entirely negligible in the hyperfine interaction, in agreement with the constituent quark model practice, where this interaction is usually neglected. More datamore » are strongly desirable, especially in the strange sector in order to fully exploit the power of this approach. We discuss possibilities of extending the calculations to other excited baryons belonging to the N = 2 or the N = 4 band.« less
  • We present the analysis of the decay widths of excited baryons in the framework of the 1/Nc expansion of QCD. These studies are performed up to order 1/Nc and include both positive and negative parity excited baryons.
  • The decays of non-strange positive parity baryons via emission of a pseudo-scalar meson are studied in the framework of the 1/Nc expansion to order 1/Nc. In particular, the pionic decays of the l=0 Roper baryons and of the l=2 baryons in the mass interval 1680-1950 MeV are analyzed using the available partial decay widths. Decay widths by emission of an eta meson are shown to be suppressed by a factor 1/Nc{sup 2} with respect to the pionic ones.
  • The masses of the negative parity 70-plet baryons are analyzed in large N{sub c} QCD to order 1/N{sub c} and to first order in SU(3) symmetry breaking. The existing experimental data are well reproduced and twenty new observables are predicted. The leading order SU(6) spin-flavor symmetry breaking is small and, as it occurs in the quark model, the subleading in 1/N{sub c} hyperfine interaction is the dominant source of the breaking. It is found that the Lambda(1405) and Lambda(1520) are well described as three-quark states and spin-orbit partners. New relations between splittings in different SU(3) multiplets are found.