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[en] The coherent 3He(e,eπ+)3H reaction was measured at Q2 = 0.4 (GeV/c)2 and W = 1.6 GeV for two values of the virtual photon polarization, ε, allowing the separation of longitudinal and transverse cross sections. The results from the coherent process on 3He were compared to H(e,eπ+)n data taken at the same kinematics. This marks the first direct comparison of these processes. At these kinematics (pπ = 1.1 GeV/c), pion rescattering from the spectator nucleons in the 3He(e,eπ+)3H process is expected to be small, simplifying the comparison to π+ production from the free proton

[en] The quasielastic (e,e[prime]p) reaction was studied on targets of deuterium, carbon, and iron up to a value of momentum transfer Q2 of 8.1 (GeV/c)2. A nuclear transparency was determined by comparing the data to calculations in the plane-wave impulse approximation. The dependence of the nuclear transparency on Q2 and the mass number A was investigated in a search for the onset of the color transparency phenomenon. We find no evidence for the onset of color transparency within our range of Q2. A fit to the world's nuclear transparency data reflects the energy dependence of the free-proton-nucleon cross section

[en] Kaon electroproduction on hydrogen, deuterium and helium targets has been measured at a beam energy of 3.245 GeV and four-momentum transfer, Q², ranging from 0.34 to 0.5 GeV². Associated hyperon production off a nucleon in the deuteron exhibits a quasifree production mechanism. Excess yield close to the respective thresholds for Λ and Σ production is observed. This can be accounted for by final-state interaction between the electroproduced hyperon and the spectator nucleon. The effects predicted from three different hyperon-nucleon potentials are compared to the data. The measurement on the helium targets is the first ever performed. Very preliminary results are presented

[en] The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q² approx. 0.35 GeV² at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed

[en] The A(e,eiK+)YX reaction on H, D, ³He, and ⁴He was investigated in Hall C at CEBAF. Data were obtained for Q² ∼ 0.35 and 0.5 GeV² at 3.245 GeV. The missing mass spectra for both H and D are fitted with Monte-Carlo simulations incorporating peaks corresponding to Lambda production on the proton and Sigma production on both the proton and neutron. For D, the cross section ratio Sigma⁰/Sigma^- ∼ 2, and excess yield close to the thresholds for Lambda and Sigma production can be attributed to final-state interactions; models are compared to the data. The analysis of the data for the He targets is in a more preliminary state with broader quasi-free peaks resulting from the higher Fermi momenta. Evidence for bound Lambda-hypernuclear states is seen and other structure may be present