Impact of recent hadron structure results on precision atomic physics calculations
Prof. Dr. Carl E. Carlson (The College of Williams & Mary, Physics Department, Williamsburg)

We will discuss the impact nuclear/particle physics experiments can have upon precision atomic physics of simple systems, and vice versa. We will be particularly interested in hydrogen hyperfine splitting, and will give some introduction about what that is (just in case), what it is good for, why one might like to calculate it accurately, and how to do so. The hyperfine splitting of the hydrogen ground state is measured to 13 figures, and is famously used by radio astronomers to map the universe. Calculating to the greatest accuracy possible, currently about a part per million accuracy, is a theoretical challenge.
The least certain part of the calculation comes from terms dependent on proton structure. We will show how to import the relevant information, and give some results and anticipations for the future.