Beam-Normal Single-Spin Asymmetry in ${}^{208}$Pb at low energy: discrepancy resolved or new kinematic puzzle?

A. Esser, N. Kozyrev, K. Aulenbacher +17

A longstanding discrepancy between measured and predicted beam-normal single-spin asymmetries $A_n$ in elastic electron scattering off ${}^{208}$Pb has challenged our understanding…