0000000000178476
AUTHOR
K. Joo
Precise Measurement of the Neutron Magnetic Form FactorGMnin the Few-GeV2Region
The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.
Measurement of the interference structure functionRLTfor the12C(e,e′p)reaction in the quasielastic region
The coincidence cross section and the interference structure function, ${R}_{\mathrm{LT}},$ were measured for the ${}^{12}\mathrm{C}{(e,e}^{\ensuremath{'}}p){}^{11}\mathrm{B}$ reaction at quasielastic kinematics and central momentum transfer of $|\stackrel{\ensuremath{\rightarrow}}{q}|=400\mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{c}.$ The measurement was at an opening angle of ${\ensuremath{\theta}}_{\mathrm{pq}}=11\ifmmode^\circ\else\textdegree\fi{},$ covering a range in missing energy of ${E}_{m}=0$ to 65 MeV. The ${R}_{\mathrm{LT}}$ structure function is found to be consistent with zero for ${E}_{m}g50\mathrm{MeV},$ confirming an earlier study which indicated that ${R}_{L}$ vanishes in this…
Measurement of the Longitudinal, Transverse, and Longitudinal-Transverse Structure Functions in theH2(e,e′p)nReaction
We have separated the longitudinal ({ital f}{sub 00}), transverse ({ital f}{sub 11}), and longitudinal-transverse interference ({ital f}{sub 01}) structure functions in the {sup 2}H({ital e},{ital e}{prime}{ital p}){ital n} reaction at {ital q}{searrow}{parallel}{approx_equal} 400 MeV/{ital c} and {omega}{approx_equal}110 MeV. A nonrelativistic calculation which includes effects due to final state interactions, meson exchange currents, and isobar configurations agrees with the measured {ital f}{sub 11} and {ital f}{sub 01} but overpredicts {ital f}{sub 00} by 25{percent} (2{sigma}). The data are also compared to the results of previous structure function measurements. {copyright} {ital 1996…
Beam-Helicity Asymmetries in Double-Charged-Pion Photoproduction on the Proton
Beam-helicity asymmetries for the two-pion-photoproduction reaction gamma + p --> p pi+ pi- have been studied for the first time in the resonance region for center-of-mass energies between 1.35 GeV and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. Beam-helicity-dependent angular distributions of the final-state particles were measured. The large cross-section asymmetries exhibit strong sensitivity to the kinematics and dynamics of the reaction. The data are compared with the results of various phenomenological model calculations, and show that these…
Relativistic Effects and Two-Body Currents inH2(e→,e′p)nUsing Out-of-Plane Detection
Measurements of the (2)H((-->)e,e(')p)n reaction were performed with the out-of-plane magnetic spectrometers (OOPS) at the MIT-Bates Linear Accelerator. The longitudinal-transverse, f(LT) and f(')(LT), and the transverse-transverse, f(TT), interference responses at a missing momentum of 210 MeV/c were simultaneously extracted in the dip region at Q2 = 0.15 (GeV/c)(2). In comparison to models of deuteron electrodisintegration, the data clearly reveal strong effects of relativity and final-state interactions and the importance of two-body meson-exchange currents and isobar configurations. We demonstrate that such effects can be disentangled by extracting these responses using the novel out-of…