Speaker
Dr
Judith McGovern
(The University of Manchester)
Description
The scalar and spin electromagnetic polarisabilities of the proton and neutron are still not particularly
well determined by Compton scattering experiments, with uncertainties ranging from somewhat less that
10% to over 100%. In the absence of free neutron targets, neutron properties must be extracted from light
nuclei, particularly the deuteron and 3He, but that requires a good understanding of the contribution of
nuclear effects and two-body currents which substantially modify the cross sections.
Chiral effective field theory provides a unied framework for the analysis of the low-energy properties
of both nucleons and light nuclei. World Compton scattering data has been used to give good constraints
on the proton scalar polarisabilities alpha and Beta [1], with progress also being made on the spin polarisabisabities [2] and prospects from a new generation of polarised scattering experiments [3, 4]. Progress is also
being made on the theoretical and experimental front for Compton scattering from light nuclei [5, 6] and
experiments are planned at both MAMI and HIgS. In this talk I will review progress in the field, and talk about future plans.
