Speaker
Description
The cross section for elastic electron-nucleus scattering is described by nuclear form factors: fundamental quantities that describe the spatial structure of the nucleus. By going to low energy and forward angle, the contributions of the magnetic form factor $G_M(Q^2)$ are minimized, which allows for an accurate extraction of the charge form factor $G_E(Q^2)$ without having to perform a Rosenbluth separation. The RMS radius of the nucleus is proportional to the slope, $dG_E/dQ^2$, as $Q^2 \to 0$, so by measuring the electric form factor of a target at very low $Q^2$, we can measure the nuclear radius.
The primary aim of my work is the extraction of the cross section from data collected in Jefferson Lab Hall A experiment E12-11-112, which measured elastic scattering from the mirror nuclei 3He and 3H at low momentum transfer $Q^2 \approx 0.1$ GeV$^2$. I will also determine the ratio of the 3He and 3H elastic cross sections since many of systematic uncertainties that enter into the absolute cross section extraction cancel in this ratio. The new results will be used to improve global fits that examine the difference between the 3H and 3He charge radii. In particular, these results will help fit the normalization of previous elastic tritium measurement and thus will dramatically improve the global fit.
