With the advent of the new MESA facility in 2019, Mainz will become a forefront laboratory for testing the Standard Model and beyond with low-energy parity-violating electron scattering (PVES). The main focus of the PVES program with MESA is a 1.5 % measurement of the proton’s weak charge. There is also the possibility of a 0.3 % measurement of the weak charge of the carbon-12 nucleus. Along with solving the purely experimental issues, this will require that the theoretical Standard Model calculations have an adequate accuracy. The main goal of this scientific program will be to lay out the theoretical foundations and possible impact of this experimental program.
The MESA PVES program does not exist isolated from other low-energy tests, and it is our aim to put the corresponding theoretical issues into a global context. While the field of low-energy tests of the Standard Model is very broad, we will concentrate on those processes which are of direct relevance for other Mainz-based experimental programs. Our program will therefore have the following cornerstones:
- Weak charge measurements with PVES at MESA.
- Parity violation in atomic systems with the goal to determine weak nuclear charges and anapole moments in isotope chains.
- The neutron distribution in heavy nuclei and the physics of neutron skins. A good knowledge of neutrons in nuclei will be needed for the interpretation of experimental results and corresponding measurements will be performed with PVES at MAMI and MESA.
- Ultra-cold neutron beta-decay with the TRIGA facility at Mainz and super-allowed nuclear beta decay and the extraction of the CKM-matrix element Vud.
In the first week, we plan to focus mostly on topics 2 and 4 (parity violation in atoms and nuclei, and beta-decay), and on topics 1 and 3 (neutron skins and weak charge measurements with PVES) in the second week. A more precise schedule will be determined at a later moment as we will try to accommodate the availability of the corresponding participants as far as possible.
Confirmed speakers are: D. Armstrong, D. Budker, V. Cirigliano, J. Hardy, W. Heil, B. Holstein, C. Horowitz, K. Kumar, F. Maas, W. Marciano, H. Meyer, M. Ramsey-Musolf, C. Sfienti, P. Souder.