Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities

Abstract

Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^{\circ }$, $125^{\circ }$, and $135^{\circ }$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and difference of the isospin-averaged nucleon polarizabilities, $\hat{I}{\pm }_N+{\hat{I}}_N^2=17.4\pm 3.7$ and $\hat{I}{\pm }_N-{\hat{I}}_N^2=6.4\pm 2.4$ (in units of $10^{-4}$ fm${}^3$), have been determined. By combining the latter with the global-averaged value for $\hat{I}{\pm }_p-{\hat{I}}_p^2$ and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of $\hat{I}{\pm }_n=8.8\pm 2.4$(total) $\pm 3.0$(model) and ${\hat{I}}_n^2=6.5\mp 2.4$(total) $\mp 3.0$(model), respectively.

4 pages, 2 figures, revtex. The text is substantially revised. The cross sections are slightly different due to improvements in the analysis