We report the 2018 self-consistent values of constants and conversion factors of physics and
chemistry recommended by the Committee on Data of the International Science Council …

Laser spectroscopy of muonic atoms has been recently used to probe properties of light
nuclei with unprecedented precision. We introduce nuclear effects in hydrogen-like atoms …

We review determinations of the electric proton charge radius from a diverse set of low-
energy observables. We explore under which conditions it can be related to Wilson …

The Cottingham formula expresses the electromagnetic part of the mass of a particle in
terms of the virtual Compton scattering amplitude. At large photon momenta, this amplitude …

A comprehensive theory of the Lamb shift in light muonic atoms such as μ H, μ D, μ 3 He+,
and μ 4 He+ is presented, with all quantum electrodynamic corrections included at the …

We consider the role of high-lying Rydberg states of simple atomic systems such as H 1 in
setting constraints on physics beyond the standard model. We obtain highly accurate bound …

A proton is a bound state of a strong interaction, governed by Quantum Chromodynamics
(QCD). The electric charge radius of a proton, denoted by r E p, characterizes the spatial …

The 1S hyperfine splitting in hydrogen is measured to an impressive ppt precision and will
soon be measured to ppm precision in muonic hydrogen. The latter measurement will rely …

We investigate the modification of the transverse electromagnetic interaction between two
pointlike particles when one particle acquires a finite size. It is shown that the correct …

We develop a method for lattice QCD calculation of the two-photon exchange contribution to
the muonic-hydrogen Lamb shift. To demonstrate its feasibility, we present the first lattice …