The Compton scattering cross section from ${}^4\mathrm{He}$ has been measured with high statistical accuracy over a scattering angle range of ${40}^{\circ }-{159}^{\circ }$ using a quasimonoenergetic 61-MeV photon beam at the High Intensity Gamma-Ray Source. The data are interpreted using a phenomenological model sensitive to the dipole isoscalar electromagnetic polarizabilities (${\alpha }_s$ and ${\beta }_s$) of the nucleon. These data can be fit with the model using values of ${\alpha }_s$ and ${\beta }_s$ that are consistent with the currently accepted values. These data will serve as benchmarks of future calculations from effective field theories and lattice quantum chromodynamics.

• Received 22 August 2017

DOI:https://doi.org/10.1103/PhysRevC.96.055209