Speaker
Description
Effective field theories are exceptionally suited to define and determine the proton radius and its relatives from low energy observables. They not only provide a unified and unambiguous definition of the low energy constants that naturally includes electromagnetic corrections, but they also yield a robust determination of the theoretical uncertainty. In this talk, I will present the effective field theory that allows us to extract the proton charge radius and its relatives from spectroscopic measurements. As an application, I will review the determination of the proton radius and the Zemach radius from measurements of the Lamb shift and the hyperfine splitting in regular and muonic hydrogen, emphasizing on the advantages of using effective field theories.