Transverse Asymmetries from Nuclei in Electron Scattering

Measurements at Jefferson Lab of the transverse asymmetry $A_T$ in few-GeV electron scattering from various nuclei at forward angles will be presented. The electron's spin is polarized transverse to its momentum. The asymmetry arises from the interference of one-photon and two-photon exchange and is a potentially important systematic for parity-violating electron scattering experiments. The nuclei measured are H, ${}^2$H, ${}^4$He, ${}^{12}$C, and ${}^{208}$Pb at corresponding kinematics ($E$, $\theta$) (GeV, degrees) = (3.18, 6), (6.06, 13), (2.75, 6), (1.05, 5) and (1.05, 5). The asymmetries are a few parts per million (ppm) and will be compared to available theoretical calculations.