Speaker
Description
The electromagnetic scalar polarizabilities ($\alpha$,$\beta$) are fundamental structure constants of the nucleon, and precise experimental measurements of these are vital for a complete understanding of the nucleon’s internal structure. The scalar polarizabilities can be accessed via Compton scattering reactions on light nuclei targets like $^1$H, $^2$H, and $^3$He. Such cross section measurements can be used to benchmark the chiral effective field theory($\chi$EFT) models. To this end, a series of Compton scattering experiments is underway at the High Intensity Gamma-Ray Source (HI$\gamma$S) at Triangle Universities Nuclear Laboratory, with the goal of extracting the electromagnetic scalar polarizabilities of the neutron ($\alpha_n$, $\beta_n$). The recently completed experiment performed Compton scattering on a liquid deuterium target at incident photon energies of 61 and 81 MeV. Backward-angle scattering cross sections were measured using two large-volume high-resolution NaI detectors. The combined effect of the quasi-monoenergetic beam at HI$\gamma$S and the excellent energy resolution of these detectors was adequate to resolve the inelastic contribution at two backward angles ($115^{\circ}$, $150^{\circ}$). Preliminary elastic and inelastic cross section data at 61 MeV will be presented.
| speaker affiliation | University of Kentucky |
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