Skip to main content
Browse by:
GROUP

Until further notice, in-person public events have been canceled. This includes recruitment events, tours, student programs, reunions, performances, conferences and social events.
Event listings include how to access online content. Contact event sponsor with questions.
Please note that all visitors to campus must comply with Duke’s community safety measures, which include wearing a mask,
check https://returnto.duke.edu/campus-visitors/ before coming to campus, and follow direction provided by campus personnel.

TUNL Lecture Series on Compton Scattering - Chiral Effective Field Theory: Pions, Nucleons and Nuclei

Event Image
Icon calendar
Thursday, July 02, 2020
Icon time
10:00 am - 11:30 am
Icon speaker
Harald W. Griesshammer
Icon series
TUNL Lecture Series on Compton Scattering

Compton scattering probes the symmetries and strengths of nucleonic and nuclear interactions and provides a bridge between data and lattice-QCD computations of fundamental hadron properties. The polarizabilities of the nucleon parametrize its stiffness against deformations in electric and magnetic fields. In these lectures, I first review the scattering of light by objects in classical electrodynamics. I introduce Effective Field Theories (EFTs) as the modern tool to describe the Natural World by a separation between short- and long-range phenomena. Nuclear Physics uses Chiral EFT, the extension of Chiral Perturbation Theory to one- and few-nucleon systems. I present formalism, recipes and limitations, and how to quantify theory uncertainties by Bayesian techniques. In the second week, I discuss the theory to extract the polarizabilities of the proton and neutron from data. We confront the results with lattice-QCD computations, and explore the impact on the neutron-proton mass difference and the Anthropic Principle. The spin polarizabilities parametrize the stiffness of the spin (nucleonic bi-refringence/Faraday effect) and probe the spin-dependent component of the pion-nucleon interaction, dictated by chiral symmetry. I review how sensitive observables for each nucleon, the deuteron and 3He are on each scalar and spin polarizability, and to their combinations.

Contact: Barry Wilson