[en] The article presents the results of studies of the characteristics of lead tungstate crystals (PbWO₄). Measurements of light transmission and light output from the passage of cosmic muons were carried out. The average light transmittance of crystals in the transverse direction is 62.82, 68.38 and 75.68% at wavelengths λ = 360, 420 and 620 nm, and the light output is ~16 pe/MeV. A prototype of electromagnetic calorimeter was designed and built from crystals arranged in 4 × 4 matrix which has been tested by cosmic muons. The results obtained confirm conclusions of other groups in the Electron-Ion Collider collaboration that quality of the crystals produced by CRYTUR meets requirements for the electromagnetic calorimeter, and that they can serve as basis for its construction

[en] We propose to measure pion electroproduction off ¹H, ², ¹²C, ⁶⁴Cu, and ¹⁹⁷Au, and extract the pion transparency through the nuclear medium between Q² = 1 and 5 (GeV/c)². The pion transparency is predicted to be a signature of the onset of nuclear filtering and/or Color Transparency. Recent experiments have reported evidence for Color Transparency effects at Q² approx 10 (GeV/c)². The occurrence of nuclear filtering could potentially explain the apparent discrepancy between (proton) nuclear transparencies found in quasielastic A(e,e'p) and A(p,2p) experiments. The occurrence of these effects is an effective signature of the approach to the factorization regime in meson electroproduction experiments, necessary for the access to Generalized Parton Distributions. Measurable effects of approx. 40% are predicted for this region of Q². The proposed experiment seeks to measure the pion transparency with 5-10% uncertainties, dominated by systematics, up to Q² = 5 (GeV/c)²

[en] We studied the reaction 12C(e,e'p) in quasielastic kinematics at momentum transfers between 0.6 and 1.8 (GeV/c)² covering the single-particle region. From this the nuclear transparency factors are extracted using two methods. The results are compared to theoretical predictions obtained using a generalization of Glauber theory described in this paper. Furthermore, the momentum distribution in the region of the 1s-state up to momenta of 300 MeV/c is obtained from the data and compared to the Correlated Basis Function theory and the Independent-Particle Shell model

[en] We have carried out an (e,ep) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment locates by direct measurement the correlated strength predicted by theory

[en] Inclusive electron scattering data are presented for ²H and Fe targets at an incident electron energy of 4.045 GeV for a range of momentum transfers from Q² = 1 to 7 (GeV/c)². Data were taken at Jefferson Laboratory for low values of energy loss, corresponding to values of Bjorken x greater than or near 1. The structure functions do not show scaling in x in this range, where inelastic scattering is not expected to dominate the cross section. The data do show scaling, however, in the Nachtmann variable ξ. This scaling may be the result of Bloom Gilman duality in the nucleon structure function combined with the Fermi motion of the nucleons in the nucleus. The resulting extension of scaling to larger values of ξ opens up the possibility of accessing nuclear structure functions in the high-x region at lower values of Q² than previously believed

[en] An experimental technique for single-Lambda spectroscopy of the light and medium-heavy mass Lambda-hypernuclei developed at the Jlab by the E01-011 Collaboration has been described. The technique is based on the electroproduction of Lambda-hypernuclei by the (e,eK+) reaction and newly constructed 2nd generation high resolution large solid angle kaon spectrometer (HKS)

[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 RSS collaboration has measured the spin structure functions g₁ and g₂ of the proton at Jefferson Lab using the lab's polarized electron beam, the Hall C HMS spectrometer and the UVa polarized solid target. The asymmetries A_parallel and A_perp were measured at the elastic peak and in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q² = 1.3 GeV². The extracted spin structure functions and their kinematic dependence make a significant contribution in the study of higher-twist effects and polarized duality tests

[en] We have measured the nuclear transparency of the A(e,e' pi⁺) process in ²H,¹²C, ²⁷Al, ⁶³Cu and ¹⁹⁷Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q² = 1.1 - 4.7 (GeV/c)². The nuclear transparency was extracted as the super-ratio of σ_Aσ_H from data to a model of pion-electroproduction from nuclei without pi-N final state interactions. The Q² and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations, and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency

[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