Many-Body Currents and the Strange-Quark Content of 4he
Abstract
Meson-exchange current (MEC) contributions to the parity-violating (PV) asymmetry for elastic scattering of polarized electrons from He are calculated over a range of momentum transfer using Monte Carlo methods and a variational He ground state wavefunction. The results indicate that MEC's generate a negligible contribution to the asymmetry at low-, where a determination of the nucleon's mean square strangeness radius could be carried out at CEBAF. At larger values of momentum transfer -- beyond the first diffraction minimum -- two-body corrections from the - \lq\lq strangeness charge" operator enter the asymmetry at a potentially observable level, even in the limit of vanishing strange-quark matrix elements of the nucleon. For purposes of constraining the nucleon's strangeness electric form factor, theoretical uncertainties associated with these MEC contributions do not appear to impose serious limitations.
Keywords
Cite
@article{arxiv.nucl-th/9405012,
title = {Many-Body Currents and the Strange-Quark Content of 4he},
author = {M. J. Musolf and R. Schiavilla and T. W. Donnelly},
journal= {arXiv preprint arXiv:nucl-th/9405012},
year = {2009}
}
Comments
32 TEX pages and 7 figures (not included, available from authors upon request), CEBAF Preprint #TH-94-10