The three loop slope of the Dirac form factor and the 1S Lamb shift in hydrogen
Abstract
The last unknown contribution to hydrogen energy levels at order m alpha 7, due to the slope of the Dirac form factor at three loops, is evaluated in a closed analytical form. The resulting shift of the hydrogen nS energy level is found to be 3.016/n3 kHz. Using the QED calculations of the 1S Lamb shift, we extract a precise value of the proton charge radius rp=0.883 0.014 fm.
0
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.