The charge-radius puzzle
Abstract: The nuclear charge radius is one of the electromagnetic moments of the nucleus and, as such, is independent of the system the nucleus is in. The observed discrepancy between muonic and electronic system, in both hydrogen and deuterium, might indicate unknown interactions that cannot be explained by straightforward modifications of the standard model. In this talk, we will briefly explain methods of high-precision atomic spectroscopy and present results of our recent work. Calculation and inclusion of the surprisingly large contribution, that was previously omitted, effectively resolves the discrepancy in the deuterium and has important implications in the context of the proton radius puzzle.