The MESA facility at Mainz will test the Standard Model and beyond with low-energy polarized electron scattering. One of the cornerstones of the experimental program at MESA, the P2 experiment, is a ~1.8% measurement of the proton’s weak charge via elastic parity-violating electron scattering (PVES), resulting in a ~0.15% determination of the weak mixing angle. PVES on C-12 is under discussion as an additional avenue for several reasons. First of all, such a measurement will serve as a calibration measurement to study the performance of the P2 experimental apparatus. Moreover, a measurement on C-12 is expected to enhance the physics output of PVES@MESA as it will probe a different isospin combination of effective 4-fermion operators.
This workshop brings together experts in the field of low-energy precision tests of the Standard Model and beyond to give an overview of experimental and theoretical activities in parity violation in electron scattering and in atoms, and coherent neutrino-nucleus scattering. The status and physics reach of the most prominent experiments - running and planned - will be discussed, and an overview of underlying theoretical frameworks within the Standard Model and beyond will be given. We pursue an important goal of fostering a dialogue between different sub-fields. Coherent neutrino scattering, parity-violating electron scattering, tests of fundamental symmetries in atomic systems are brought under the same roof with neutrino oscillations, inelastic neutrino scattering, physics of neutron skins and nuclear beta decays. We will discuss outstanding challenges, common and distinct in each field, and ways how the respective communities can interact to maximize the impact of these exciting experimental and theoretical studies.
