T. W. Donnelly

Considerations of polarization in inclusive electron scattering from nuclei

Inclusive electron scattering of either unpolarized or polarized electrons, (e, e′) or (e, e′), from polarized nuclei is considered. General formulas are given for arbitrary nuclear transitions and polarizations, in the extreme relativistic limit for the electron, and examples where the nuclear states involved have specific angular momenta and parities are discussed in some detail.

Intermediate-energy semileptonic probes of the hadronic neutral current☆

The present status and future prospects of intermediate-energy semileptonic neutral current studies are reviewed. Possibilities for using parity-violating electron scattering from nucleons and nuclei to study hadron structure and nuclear dynamics are emphasized, with particular attention paid to probes of strangeness content in the nucleon. Connections are drawn between such studies and tests of the electroweak gauge theory using electron or neutrino scattering. Outstanding theoretical issues in the interpretation of semileptonic neutral current measurements are highlighted and the prospects for undertaking parity-violating electron or neutrino scattering experiments in the near future are surveyed.

Polarization in Coincidence Electron Scattering From Nuclei

Abstract Theoretical analysis of the uses of leptonic and nuclear polarization degrees of freedom in the extraction of information on nuclear structure and dynamics from exclusive electron-nucleus scattering is presented. The formalism is discussed in its most general form in terms of multipole matrix elements of the hardronic current with all particles polarized and is then specialized to a variety of cases of interest in intermediate-energy nuclear physics. These studies suggest that control of polarization degrees of freedom will provide an important means to extend the usefulness of lepton-scattering experiments for the measurement of the electromagnetic properties of nuclei.

-Measurement of the proton's electric to magnetic form factor ratio from 1H(over -->)(e(over -->),e'p).

We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared Q2 from 0.15 to 0.65 (GeV/c)(2). Significantly improved results on the proton electric and magnetic form factors are obtained in combination with existing cross-section data on elastic electron-proton scattering in the same Q2 region.

Measurement of the proton's electric to magnetic form factor ratio from H→1(e→,e′p)

We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared Q2 from 0.15 to 0.65 (GeV/c)(2). Significantly improved results on the proton electric and magnetic form factors are obtained in combination with existing cross-section data on elastic electron-proton scattering in the same Q2 region.

Isospin dependences in parity-violating electron scattering

Abstract The role of the isospin structure of nuclear states in parity-violating single-arm electron scattering from nuclei is examined. Specific examples of elastic scattering from even-even N = Z (0 + , M T = 0, nominally T = 0) nuclei, which are supposed to be ideally suited for studying the electroweak interaction, are considered in detail. The aim is to find when nuclear structure effects due to isospin impurities significantly enter into the parity-violating asymmetry, and hence to determine the level of precision at which one can hope to extract the underlying weak neutral current couplings in a relatively model-independent way. The formalism is then extended to the general case of J > 0 states and even-even N ≠ Z nuclei. Finally, it is shown that measurement of the parity-violating asymmetry may provide a determination of the neutron distribution in nuclei.

Using electron scattering superscaling to predict charge-changing neutrino cross sections in nuclei

Superscaling analyses of few-GeV inclusive electron scattering from nuclei are extended to include not only quasielastic processes, but also the region where {delta} excitation dominates. With reasonable assumptions about the basic nuclear scaling function extracted from data and information from other studies of the relative roles played by correlation and meson-exchange-current effects, it is shown that the residual strength in the resonance region can be accounted for through an extended scaling analysis. One observes scaling upon assuming that the elementary cross section by which one divides the residual to obtain a new scaling function is dominated by the N{yields}{delta} transition and employing a new scaling variable suited to the resonance region. This yields a good representation of the electromagnetic response in both the quasielastic and {delta} regions. The scaling approach is then inverted and predictions are made for charge-changing neutrino reactions at energies of a few GeV, with focus placed on nuclei that are relevant to neutrino oscillation measurements. For this, a relativistic treatment of the required weak interaction vector and axial-vector currents for both quasielastic and {delta}-excitation processes is presented.

Quasielastic scattering from relativistic bound nucleons: Transverse longitudinal response

Predictions for electron induced proton knockout from the

Meson-exchange currents and quasielastic antineutrino cross sections in the SuperScaling Approximation

p_{1/2}

Pionic effects in quasielastic electron scattering

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