Precision Measurement of sin2(theta_w) at MESA
  A forthcoming experiment of low-energy elastic electron proton scattering at the new MESA facility in Mainz is planned to provide a high-precision measurement of the parity-violating polarisation asymmetry. This experiment is expected to lead to a precision determination of the weak mixing angle, competitive with Z-pole data. We discuss the challenges for theory to derive predictions with the required accuracy. 
R. Bucoveanu, M. Gorchtein, H. Spiesberger
hep-ph