The 50<Eg< 70 MeV tagged photons were scattered from a liquid deuterium target and detected simultaneously in three (nominal 10" x 12") NaI detectors. The average laboratory angles investigated were 45, 130, and 135 deg. Measurements were made at two backward angles because of greatly enhanced experimental sensitivity. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing-energy spectrum. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment, resulting in 18 data points in total. The extracted cross sections are in good agreement with those measured at Illinois reported by Lucas et al.
The calculations of Levchuk and L'vov were fit to the data to extract the difference between the electric and magnetic isospin-averaged polarizabilities of the nucleon inside the deuteron, holding the sum fixed at 15 (10-4 fm3). The result of the fit implies that the electric and magnetic polarizabilities of the neutron are identical to those of the proton within the estimated experimental uncertainties.
This work was supported by the Swedish Natural Science Research Council and the Royal Physiographic Society in Lund, Sweden.