Separated Structure Functions for the Exclusive Electroproduction of $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ Final States

Abstract

We report measurements of the exclusive electroproduction of $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ final states from a proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions ${\sigma }_T$, ${\sigma }_L$, ${\sigma }_{TT}$, and ${\sigma }_{LT}$ were extracted from the $\Phi$- and $\epsilon$-dependent differential cross sections taken with electron beam energies of 2.567, 4.056, and 4.247 GeV. This analysis represents the first ${\sigma }_L/{\sigma }_T$ separation with the CLAS detector, and the first measurement of the kaon electroproduction structure functions away from parallel kinematics. The data span a broad range of momentum transfers from $0.5\le Q^2\le 2.8$ GeV${}^2$ and invariant energy from $1.6\le W\le 2.4$ GeV, while spanning nearly the full center-of-mass angular range of the kaon. The separated structure functions reveal clear differences between the production dynamics for the $\Lambda$ and ${\Sigma }^0$ hyperons. These results provide an unprecedented data sample with which to constrain current and future models for the associated production of strangeness, which will allow for a better understanding of the underlying resonant and non-resonant contributions to hyperon production.

61 pages, 26 figures, 5 tables

References in corpus (23)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Differential Cross Sections for gamma + p --> K+ + Y for Lambda and Sigma0 Hyperons
• Measurement of gamma p --> K+ Lambda and gamma p --> K+ Sigma0 at photon energies up to 2.6 GeV
• Evidence for a missing nucleon resonance in kaon photoproduction
• Strange Decays of Nonstrange Baryons
• Hyperon Photoproduction 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
• Gauge-invariant tree-level photoproduction amplitudes with form factors
• Photo- and Electroproduction of Eta Mesons
• Beam polarization asymmetries for the p(gamma,K+)Lambda and p(gamma,K+)Sigma0 reactions at Egamma=1.5-2.4 GeV
• Decays of Baryon Resonances into K Lambda, K^+ Sigma^0 and K^0 Sigma^+
• Kaon photoproduction: background contributions, form factors and missing resonances
• Differential cross section and photon beam asymmetry for the gamma n -> K+ Sigma- reaction at Egamma=1.5-2.4 GeV
• First Measurement of Transferred Polarization in the Exclusive e p --> e' K+ Lambda Reaction
• Separation of the Longitudinal and Transverse Cross Sections in the p(ee'K)Lambda and p(ee'K)Sigma Reactions
• The role of hyperon resonances in p(gamma,K+)Lambda processes
• QED Radiative Corrections in Processes of Exclusive Pion Electroproduction
• A Genetic Algorithm Analysis of N* Resonances in $p(\gamma ,K^{+})\Lambda$ Reactions
• Electroproduction of strangeness above the resonance region
• Constraints on background contributions from K+ Lambda electroproduction
• Ratio of ${\sigma }_L/{\sigma }_T$ for $p(e,e^{\prime }{K}^{+})\Lambda$ Extracted from Polarization Transfer
• From known to undiscovered resonances

Cited by in corpus (36)

• Baryon spectroscopy
• Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction
• Electroexcitation of nucleon resonances
• 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
• Model Analysis of the $ep\to e{p}^{\prime }{\pi }^{+}{\pi }^{-}$ Electroproduction Reaction on the Proton
• Strong QCD Insights from Excited Nucleon Structure Studies with CLAS and CLAS12
• 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
• Electromagnetic production of kaon near threshold
• Electroproduction of kaons from the proton in a Regge-plus-resonance approach
• Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ for $p(\vec{e},e^{\prime }{K}^{+})\Lambda$ in the Nucleon Resonance Region
• 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 and Rosenbluth separations in 1H(e, e'K+)Lambda up to Q2=2.35 GeV2
• Electromagnetic production of $K\Sigma$ on the nucleon near threshold
• Separated Structure Functions for Exclusive $K^{+}\Lambda$ and $K^{+}{\Sigma }^0$ Electroproduction at 5.5 GeV with CLAS
• Exclusive electroproduction of K+ Lambda and K+ Sigma^0 final states at Q^2 = 0.030-0.055 (GeV/c)^2
• 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
• Strangeness Suppression in q-qbar Creation Observed in Exclusive Reactions
• Beam-Recoil Transferred Polarization in $K^{+}Y$ Electroproduction in the Nucleon Resonance Region with CLAS12
• $K^{+}\Lambda$ electroproduction above the resonance region
• Progress and Issues in the Electromagnetic Production of Kaon on the Nucleon
• Theory of the electromagnetic production of hyperons
• Nucleon Resonance Structure Studies Via Exclusive KY Electroproduction
• Photon induced K$\Lambda$ production on the proton in the low energy region
• Gerasimov-Drell-Hearn Sum Rule and the Discrepancy between the New CLAS and SAPHIR Data
• Charged lepton induced one kaon production off the nucleon
• Polarization of Hyperons in Elementary Photoproduction
• Hyperon Photo and Electro Production at CLAS
• The N* Physics Program at Jefferson Lab
• Meson Production and Baryon Resonances at CLAS
• Instanton-Induced Polarization in Exclusive Hyperon Photoproduction
• Probing the nucleon structure with CLAS
• Excited Baryon Structure Using Exclusive Reactions with CLAS12
• Strangeness Physics with CLAS at JLab