Quark spin content of the proton, hyperon semileptonic decays, and the decay width of the {theta}{sup +} pentaquark

Journal Article · Tue May 01 04:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.75.094004· OSTI ID:21020476

Yang, Ghil-Seok; Goeke, Klaus ^[1]; Kim, Hyun-Chul ^[2]

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1. Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)
2. Department of Physics, and Nuclear Physics and Radiation Technology Institute (NuRI), Pusan National University, 609-735 Busan (Korea, Republic of)

Using the exisiting experimental data for hyperon semileptonic decays and the flavor-singlet axial-vector charge g{sub A}{sup (0)} from polarized deep inelastic scattering of the proton, we derive the decay width of the {theta}{sup +} pentaquark baryon. We take into account the effects of flavor SU(3) symmetry breaking within the framework of the chiral quark-soliton model. All dynamical parameters of the model are fixed by using the five experimental hyperon semileptonic decay constants and flavor-singlet axial-vector charge. We obtain the numerical results of the decay width of the {theta}{sup +} pentaquark baryon as a function of the pion-nucleon sigma term {sigma}{sub {pi}}{sub N} and investigate the dependence of the decay width of the {theta}{sup +} on the g{sub A}{sup (0)}, varying the g{sub A}{sup (0)} within the range of the experimental uncertainty. We demonstrate that the combined values of all known semileptonic decays with the generally accepted value of g{sub A}{sup (0)}{approx_equal}0.3 for the proton are compatible with a small decay width {gamma}{sub {theta}}{sub KN} of the {theta}{sup +} pentaquark, i.e. {gamma}{sub {theta}}{sub KN}{<=}1 MeV.

• OSTI ID: 21020476
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 75; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRALITY
DEEP INELASTIC SCATTERING
FLAVOR MODEL
HYPERONS
MEV RANGE
PARTICLE WIDTHS
PION-NUCLEON INTERACTIONS
PIONS
PROTONS
QUARKS
REST MASS
SEMILEPTONIC DECAY
SOLITONS
SPIN
SU-3 GROUPS