0000000000178627
AUTHOR
Michael Dugger
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.
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…
Angular distribution of scattered electrons associated with collimated bremsstrahlung and the tagging technique
Abstract We investigate the angular correlation between a bremsstrahlung photon and its corresponding post-bremsstrahlung electron within the context of a magnetic tagging spectrometer with the aim of improving the instrument's efficiency. Our results are given in terms of angular distributions of the post-bremsstrahlung electron associated with photons that pass through a circular collimator centered in the forward direction. We start from the fully differential Bethe–Heitler (first Born approximation) cross-section, including the Moliere screening correction, which is then integrated over the photon azimuthal angle and over the photon polar angle defined by the collimator. These integrati…