Analyzing the effects of neutron polarizabilities in elastic Compton scattering off 3He Original Research Article

Motivated by the fact that a polarized 3He nucleus is expected to behave approximately as a polarized neutron, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate both unpolarized and double-polarization observables using chiral perturbation theory to next-to-leading order (O(e2Q)) at energies, ω≲mπ, where mπ is the pion mass. Our results show that the unpolarized differential cross-section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities.