Title: The Flavor Structure of the Excited Baryon Spectra from Lattice QCD

Abstract

Excited state spectra are calculated using lattice QCD for baryons that can be formed from $$u$$, $$d$$ and $$s$$ quarks, namely the $$N$$, $$\Delta$$, $$\Lambda$$, $$\Sigma$$, $$\Xi$$ and $$\Omega$$ families of baryons. Baryonic operators are constructed from continuum operators that transform as irreducible representations of SU(3)$$_F$$ symmetry for flavor, SU(4) symmetry for Dirac spins of quarks and O(3) symmetry for orbital angular momenta. Covariant derivatives are used to realize orbital angular momenta. Using the operators, we calculate matrices of correlation functions in order to extract excited states. The resulting lattice spectra have bands of baryonic states with well-defined total spins up to $J=7/2$. Each state can be assigned a dominant flavor symmetry and the counting of states of each flavor and spin reflects $$SU(6) \times O(3)$$ symmetry for the lowest negative-parity and positive-parity bands. States with strong hybrid content are identified through the dominance of chromo-magnetic operators.

Authors:

Edwards, Robert G. ^[1]; Mathur, Nilmani ^[2]; Richards, David G. ^[1]; Wallace, Stephen J ^[3]

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+ Show Author Affiliations

1. JLAB
2. Tata Institute
3. Maryland U.

Publication Date:

2013-03-01

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1076592

Report Number(s):

JLAB-THY-12-1680; DOE/OR/23177-2513; arXiv:1212.5236

DOE Contract Number:  

AC05-06OR23177

Resource Type:

Journal Article

Journal Name:

Phys. Rev. D

Additional Journal Information:

Journal Volume: 87; Journal Issue: 5

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS