Low-lying {Lambda} baryons with spin 1/2 in two-flavor lattice QCD

Journal Article · Mon Feb 01 00:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.034505· OSTI ID:21409191

Takahashi, Toru T ^[1]; Oka, Makoto ^[2]

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1. Yukawa Institute for Theoretical Physics, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
2. Department of Physics, H-27, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan)

Low-lying {Lambda} baryons with spin 1/2 are analyzed in full (unquenched) lattice QCD. We construct 2x2 cross correlators from flavor SU(3) octet and singlet baryon operators, and diagonalize them so as to extract information of two low-lying states for each parity. The two-flavor CP-PACS gauge configurations are used, which are generated in the renormalization-group improved gauge action and the O(a)-improved quark action. Three different {beta}'s, {beta}=1.80, 1.95, and 2.10, are employed, whose corresponding lattice spacings are a=0.2150, 0.1555, and 0.1076 fm. For each cutoff, we use four hopping parameters, ({kappa}{sub val},{kappa}{sub sea}), which correspond to the pion masses ranging about from 500 MeV to 1.1 GeV. Results indicate that there are two negative-parity {Lambda} states nearly degenerate at around 1.6 GeV, while no state as low as {Lambda}(1405) is observed. By decomposing the flavor components of each state, we find that the lowest (1st-excited) negative-parity state is dominated by flavor-singlet (flavor-octet) component. We also discuss meson-baryon components of each state, which has drawn considerable attention in the context of multiquark pictures of {Lambda}(1405).

• OSTI ID: 21409191
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 3; Other Information: DOI: 10.1103/PhysRevD.81.034505; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CONFIGURATION
FLAVOR MODEL
GEV RANGE 01-10
LAMBDA-1405 BARYONS
MASS
MEV RANGE 100-1000
PARITY
PERTURBED ANGULAR CORRELATION
PIONS
QUANTUM CHROMODYNAMICS
QUARKS
RENORMALIZATION
SPIN
ANGULAR CORRELATION
ANGULAR MOMENTUM
BARYONS
BOSONS
COMPOSITE MODELS
CORRELATIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FIELD THEORIES
GEV RANGE
HADRONS
HYPERONS
LAMBDA BARYONS
MATHEMATICAL MODELS
MESONS
MEV RANGE
PARTICLE MODELS
PARTICLE PROPERTIES
PSEUDOSCALAR MESONS
QUANTUM FIELD THEORY
QUARK MODEL
STRANGE PARTICLES