### Session EF: Mini-Symposium on Hadron Structure and QCD in High Energy Processes II

9:00 AM–12:00 PM, Friday, October 16, 2009
Room: Kohala 3

Chair: Misak Sargsian, Florida International University

Abstract ID: BAPS.2009.HAW.EF.6

### Abstract: EF.00006 : Target Single-Spin Asymmetry Measurements in Quasi-Elastic $^{3}$He$\uparrow$(e, e$'$)

10:15 AM–10:30 AM

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#### Author:

Bo Zhao
(College of William and Mary)

The target single-spin asymmetry for the neutron, $A_{y}$, was measured using the inclusive quasi-elastic $^{3}$He$\uparrow$(e, e$'$) reaction in Hall A at Jefferson Lab with a vertically polarized $^{3}$He target for $Q^{2}$ = 0.13, 0.46 and 0.97 GeV$^{2}$. Since the target single-spin asymmetry is expected to be zero in the one-photon exchange approximation, the non-zero results from this experiment clearly demonstrate the effects due to two-photon exchange. They establish the two-photon exchange process as a powerful tool to probe hadron structure, such as information on Generalized Parton Distributions. The ongoing analysis of this experiment will be presented.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.HAW.EF.6