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Measurement of the $^{3}$He and Neutron Spin Structure at Low Q$^{2}$

ORAL

Abstract

The Gerasimov-Drell-Hearn (GDH) sum rule was originally derived for real photon absorption (corresponding to Q$^{2}$=0) and has been generalized to finite Q$^{2}$. The goal of Jefferson Lab experiment E97-110 is to perform a precise measurement of the generalized GDH integral and the moments of the neutron spin structure functions in order to study their Q$^{2}$ dependence between 0.02 and 0.3 (GeV/c)$^{2}$. This Q$^{2}$ range will allow us to test the dynamics of Chiral Perturbation Theory, extrapolate to the integral's real photon point for $^{3}$He and the neutron, and will complement a previous experiment at higher Q$^{2}$. The measurement will provide new constraints on the $^{3}$He and neutron spin structure and contribute to the understanding of the nucleon resonances. The acquisition of data was completed using the Jefferson Lab high polarization continuous-wave electron beam, the Hall A polarized $^{3}$He target, and one of the Hall A septum magnets, which allow measurements at forward angles of 6 and 9 degrees. The status and prospects will be discussed.

Authors

  • Vincent Sulkosky

    The College of William and Mary