Roper Resonance in 2+1 Flavor QCD

Journal Article · Tue May 24 04:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3587582· OSTI ID:21516878

Mahbub, M Selim; Kamleh, Waseem; Leinweber, Derek B; Williams, Anthony G ^[1]; Moran, Peter J ^[1]

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1. Special Research Centre for the Subatomic Structure of Matter, Adelaide, South Australia 5005 and Department of Physics, University of Adelaide, South Australia 5005 (Australia)

The low-lying even-parity states of the nucleon are explored in lattice QCD using the PACS-CS collaboration 2+1-flavor dynamical-QCD gauge-field configurations. The established correlation-matrix approach is used, in which various fermion source and sink smearings are utilized to provide an effective basis of interpolating fields to span the space of low-lying energy eigenstates. Of particular interest is the nature of the first excited state of the nucleon, the N(1/2){sup +} Roper resonance of P{sub 11} pion-nucleon scattering. The Roper state of the present analysis approaches the physical mass, displaying significant chiral curvature at the lightest quark mass. These full QCD results, providing the world's first insight into the nucleon mass spectrum in the light-quark regime, are significantly different from those of quenched QCD and provide interesting insights into the dynamics of QCD.

• OSTI ID: 21516878
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1354; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR CORRELATION
BARYONS
BOSONS
CHIRALITY
COMPOSITE MODELS
CONFIGURATION
CONSTRUCTIVE FIELD THEORY
CORRELATIONS
D QUARKS
ELEMENTARY PARTICLES
ENERGY LEVELS
EXCITED STATES
FERMIONS
FIELD THEORIES
FLAVOR MODEL
GAUGE INVARIANCE
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
INTERPOLATION
INVARIANCE PRINCIPLES
LATTICE FIELD THEORY
MASS
MASS SPECTRA
MATHEMATICAL MODELS
MATHEMATICAL SOLUTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
N BARYONS
N*BARYONS
N-1440 BARYONS
NUCLEONS
NUMERICAL SOLUTION
PARITY
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PERTURBED ANGULAR CORRELATION
PION-NUCLEON INTERACTIONS
PIONS
PSEUDOSCALAR MESONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK MODEL
QUARKS
SINKS
SPECTRA
U QUARKS