This article reviews recent developments in tests of fundamental physics using atoms and
molecules, including the subjects of parity violation, searches for permanent electric dipole …

Recent developments in frequency metrology and optical clocks have been based on
electronic transitions in atoms and singly charged ions as references. The control over all …

The surprising discrepancy between results from different methods for measuring the proton
charge radius is referred to as the proton radius puzzle. In particular, measurements using …

At the core of the “proton radius puzzle” is a four–standard deviation discrepancy between
the proton root-mean-square charge radii (rp) determined from the regular hydrogen (H) and …

High-resolution laser spectroscopy is an established powerful tool in the study of nuclear
shape, size and multipole moments. Measurements of the hyperfine structures and isotope …

The proton size, specifically its charge radius, was thought known to about 1% accuracy.
Now a new method probing the proton with muons instead of electrons finds a radius about …

We present a measurement of the hydrogen 2 S 1/2-8 D 5/2 transition performed with a
cryogenic atomic beam. The measured resonance frequency is ν= 770 649 561 570.9 (2.0) …

We review the spectrum and electromagnetic properties of baryons described as relativistic
three-quark bound states within QCD. The composite nature of baryons results in a rich …

We highlight the progress, current status, and open challenges of QCD-driven physics, in
theory and in experiment. We discuss how the strong interaction is intimately connected to a …

This new edition of The Standard Model and Beyond presents an advanced introduction to
the physics and formalism of the standard model and other non-abelian gauge theories. It …