Quark spin content of the proton, hyperon semileptonic decays, and the decay width of the $Θ^{+}$ pentaquark

dc.creatorYang, Ghil-Seok
dc.creatorKim, Hyun-Chul
dc.creatorGoeke, Klaus
dc.date2007-01-20
dc.date2007-04-19
dc.date.accessioned2026-07-07T10:22:17Z
dc.date.available2026-07-07T10:22:17Z
dc.descriptionUsing the exisiting experimental data for hyperon semileptonic decays and the flavor-singlet axial-vector charge $g_{A}^{(0)}$ from polarized deep inelastic scattering of the proton, we derive the decay width of the $Θ^{+}$ 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 $Θ^{+}$ pentaquark baryon as a function of the pion-nucleon sigma term $Σ_{πN}$ and investigate the dependence of the decay width of the $Θ^{+}$ on the $g_{A}^{(0)}$, varying the $g_{A}^{(0)}$ within the range of the experimental uncertainty. We demonstrate that the combined values of all known semileptonic decays with the generally accepted value of $g_{A}^{(0)} \approx 0.3$ for the proton are compatible with a small decay width $Γ_{ΘKN}$ of the $Θ^{+}$ pentaquark, i.e. $Γ_{ΘKN} \leq 1$ MeV.
dc.description11 pages, 2 figures. Title has been changed, some of the text has been modified, and more references have been added. The final version accepted for publication in Phys. Rev. D
dc.identifierhttps://arxiv.org/abs/hep-ph/0701168
dc.identifierhttp://arxiv.org/abs/hep-ph/0701168
dc.identifierPhys.Rev.D75:094004,2007
dc.identifierdoi:10.1103/PhysRevD.75.094004
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/175465
dc.subjectHigh Energy Physics - Phenomenology
dc.titleQuark spin content of the proton, hyperon semileptonic decays, and the decay width of the $Θ^{+}$ pentaquark
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