First Measurement of Transferred Polarization in the Exclusive e p --> e' K+ Lambda Reaction

Abstract

The first measurements of the transferred polarization for the exclusive ep --> e'K+ Lambda reaction have been performed in Hall B at the Thomas Jefferson National Accelerator Facility using the CLAS spectrometer. A 2.567 GeV electron beam was used to measure the hyperon polarization over a range of Q2 from 0.3 to 1.5 (GeV/c)2, W from 1.6 to 2.15 GeV, and over the full center-of-mass angular range of the K+ meson. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A non-relativistic quark model interpretation of our data suggests that the s-sbar quark pair is produced with spins predominantly anti-aligned. Implications for the validity of the widely used 3P0 quark-pair creation operator are discussed.

6 pages, 4 figures

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• Evidence for a missing nucleon resonance in kaon photoproduction
• Kaon photoproduction: background contributions, form factors and missing resonances
• Lambda polarization and single-spin left-right asymmetry in diffractive hadron-hadron collisions

Cited by in corpus (42)

• Baryon spectroscopy
• Electroexcitation of nucleon resonances
• Electromagnetic Meson Production in the Nucleon Resonance Region
• The gamma + p to K+ + Lambda and gamma + p to K+ + Sigma0 reactions at forward angles with photon energies from 1.5 to 2.4 GeV
• First Measurement of Beam-Recoil Observables Cx and Cz in Hyperon Photoproduction
• New Results from the Studies of the $N(1440)1/2^{+}$, $N(1520)3/2^{-}$, and $\Delta (1620)1/2^{-}$ Resonances in Exclusive $ep\to e^{\prime }{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction with the CLAS Detector
• Deeply Virtual Meson Production on the nucleon
• Differential cross section and photon beam asymmetry for the gamma n -> K+ Sigma- reaction at Egamma=1.5-2.4 GeV
• Separated Structure Functions for the Exclusive Electroproduction of $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ Final States
• Model Analysis of the $ep\to e{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction Reaction on the Proton
• A Genetic Algorithm Analysis of N* Resonances in $p(\gamma ,K^{+})\Lambda$ Reactions
• Strong QCD Insights from Excited Nucleon Structure Studies with CLAS and CLAS12
• Pion- and photo-induced transition amplitudes to $\Lambda K$, $\Sigma K$, and $N\eta$
• Beam-Recoil Polarization Transfer in the Nucleon Resonance Region in the Exclusive $\vec{e}p\to e^{\prime }{K}^{+}\vec{\Lambda }$ and $\vec{e}p\to e^{\prime }{K}^{+}{\vec{\Sigma }}^0$ Reactions at CLAS
• Kaon Photoproduction and the $\Lambda$ Decay Parameter ${\alpha }_{-}$
• Longitudinal Spin Transfer to the $\Lambda$ Hyperon in Semi-Inclusive Deep-Inelastic Scattering
• Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ for $p(\vec{e},e^{\prime }{K}^{+})\Lambda$ in the Nucleon Resonance Region
• Electroproduction of kaons from the proton in a Regge-plus-resonance approach
• Exclusive electromagnetic production of strangeness on the nucleon : review of recent data in a Regge approach
• Electroproduction of p π^{+} π^{-} off protons at 0.2<Q^{2}<0.6 GeV^{2} and 1.3<W<1.57 GeV with CLAS
• Cross Sections for the $\gamma p\to K^{\ast 0}{\Sigma }^{+}$ Reaction at $E_{\gamma }=1.7-3.0$ GeV
• Electric and magnetic form factors of strange baryons
• Dynamical coupled-channel model of kaon-hyperon interactions
• Separated Structure Functions for Exclusive $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ Electroproduction at 5.5 GeV with CLAS
• Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model
• New fits to the reaction $\gamma p\to K^{+}\Lambda$
• Induced polarization of Λ(1116) in kaon electroproduction
• Ratio of ${\sigma }_L/{\sigma }_T$ for $p(e,e^{\prime }{K}^{+})\Lambda$ Extracted from Polarization Transfer
• Beam-Recoil Transferred Polarization in $K^{+}Y$ Electroproduction in the Nucleon Resonance Region with CLAS12
• Polarization in Hyperon Photo- and Electro- Production
• Resonances, and mechanisms of Theta-production
• Progress and Issues in the Electromagnetic Production of Kaon on the Nucleon
• Today's View on Strangeness
• Nucleon Resonance Structure Studies Via Exclusive KY Electroproduction
• Transverse Polarization of ${\Sigma }^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS
• Charged lepton induced one kaon production off the nucleon
• First Measurement of ${\Xi }^{-}$ Polarization in Photoproduction
• Hyperon Photo and Electro Production at CLAS
• Instanton-Induced Polarization in Exclusive Hyperon Photoproduction
• Longitudinal Spin Transfer to $\Lambda$ Hyperons in Semi-Inclusive Deep Inelastic Scattering with CLAS12
• Probing the nucleon structure with CLAS
• Excited Baryon Structure Using Exclusive Reactions with CLAS12