PD Dr. Michaela Thiel (JGU Mainz): 208Pb and the last crusade: high-precision electron scattering experiments at MAMI and MESA

Where do the neutrons go? The study of neutron-rich matter provides fundamental insights into the structure of heavy nuclei as well as neutron stars. Although they differ in size by orders of magnitude, both are governed by the same underlying physics, which is enshrined in the nuclear Equation of State (EoS). An accurate and model-independent determination of the neutron-skin thickness of 208Pb, using parity-violating electron scattering, would provide significant constraints on the density dependence of the nuclear symmetry energy, a key parameter of the EoS, and, ultimately, on some critical properties of neutron stars. For the analysis of these parity-violation measurements at the precision frontier, it is crucial to go beyond the Born approximation and include higher-order corrections. Corresponding measurements of the beam-normal single spin asymmetry An, an observable sensitive to two-photon exchange processes, led to unexpected results.
Focusing on ongoing and future electron scattering experiments at MAMI and MESA, this talk aims to highlight how these precision measurements provide essential constraints for understanding the structure and behavior of neutron-rich matter.
Cookies, tea