

This experiment will measure the target singlespin asymmetry, A_{y} , for the neutron using the inclusive quasielastic ^{3}He^{↑}(e,e') reaction in Hall A with a vertically polarized ^{3}He target at Q^{2} = 1.0 and 2.3 GeV^{2}. In the onephoton exchange approximation, A_{y} is identically zero due to timereversal invariance. However, it is also sensitive to the twophoton exchange amplitude which can be nonzero and enters A_{y} through the interference between the one and twophoton amplitudes. For large enough Q^{2}, where the scattering predominantly occurs from asymptoticallyfree partons, there are contributions from both the elastic and inelastic nucleon response during twophoton exchange. Calculation of the elastic response is straightforward and yields an asymmetry of A^{n}_{y,elas} ≅ 0.005 for the neutron at the kinematics of this experiment. The inelastic response was recently calculated using models of Generalized Parton Distributions (GPD's) as input and is on the order of A^{n}_{y,inel} ≅ 0.01, which gives a total expected asymmetry of A^{n}_{y} ≅ 0.015. Two different moments, each containing two of the GPD's, are needed to fully describe the inelastic response. However for the neutron, A_{y} is dominated by just one of these moments that contains the GPD's, H^{q} and E^{q}, that are also related to the nucleon form factors and the total angular momentum contribution to the nucleon spin from the quarks. This experiment will be performed using the standard Hall A spectrometers and a vertically polarized ^{3}He target and will measure A^{n}_{y} with an absolute statistical uncertainty of δA_{y} ≅ 0.0023 at each Q^{2} (15% relative to the prediction above). This experiment will be the first to firmly establish a nonvanishing A_{y}, a Todd quantity that is identically zero in the Born approximation, providing new constraints on GPD models and new information on the dynamics of the twophoton exchange process. 

