Speaker
Description
What happens when a proton is subjected to an electric field? The simple answer from first-year physics is that it would move. The less simple answer is that it would also deform due to the internal structure of the proton. Such is also the case in a magnetic field, and similarly so for the neutron, which obviously would have otherwise remained at rest. These responses to electric and magnetic fields are described by parameters of the nucleon called polarizabilities. The A2 collaboration at the Mainz Microtron has undertaken a multi-experiment project to extract these polarizabilities. This is done by taking polarized photons, provided from tagged Bremsstrahlung, and Compton scattering them off of either polarized or unpolarized protons. The measurements of various observables from these experiments are then compared with theoretical values from dispersion and chiral perturbation calculations. Values for the proton polarizabilities, some of which had not been experimentally determined previously, have been extracted, and plans to improve these values and continue the program on the neutron are underway.
