We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the helium-3 nucleus. We calculate $\gamma {}^3\mathrm{He}$ elastic scattering observables using chiral perturbation theory to next-to-leading order [$\mathcal{O}(e^{2}Q)$]. We find 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.

• Received 5 February 2007

DOI:https://doi.org/10.1103/PhysRevLett.98.232303