Speaker
Description
Charge, magnetic and Zemach radii of light nuclei characterize the distribution of electromagnetic charge inside the corresponding nuclei and are a perfect tool to test modern high-precision nuclear forces. Experimentally, these radii can be extracted from electron scattering and the laser spectroscopy of normal and muonic atoms with precision often reaching sub-percent level. Theoretical description with a similar accuracy level requires a very good understanding of two- and three-body forces, two-body electromagnetic currents, and various relativistic effects.
We present a high-accuracy calculation of electromagnetic form factors of A=2,3,4 nuclei based on the latest two- and three-nucleon forces, electromagnetic current operators derived up through the fifth order in the chiral effective field theory. We predict electric and magnetic structure radii and perform a comprehensive and systematic analysis of various sources of uncertainty. Using the predicted values of the ${}^2$H and ${}^4$He structure radii combined with the spectroscopic measurements of the deuteron-proton charge radius difference and ${}^4$He charge radius we extract the neutron and proton charge radii.
