Speaker
Description
The talk will review the recent series of Hall A experiments at Jefferson Lab to measure the elastic electric and magnetic form factors of the proton and neutron to a large $Q^2$ which would doubled or tripled the $Q^2$ range of previous precision measurements. Two large acceptance spectrometers were used so that the form factors could be measured with high precision. From 2021 to 2024, the neutron form factor experiments used the BigBite Spectrometer to detect electrons and the Super BigBite Spectrometer to detect the quasi-elastically scattered neutrons. The neutron's magnetic form factor was measured up to $Q^2$ = 13.5 GeV$^2$. The neutron's electric form factor was measured up to $Q^2$ = 10 GeV$^2$. In early 2025, the proton's electric form factor will be measured up to $Q^2$ = 12 GeV$^2$ with BigBite Spectrometer replaced by a combination of large acceptance scintillator array and electron calorimeter for the detection of electrons and the SBS detecting the elastically scattered protons. The recent experiments will be discussed in context of previous nucleon form factor experiments and theoretical calculations.
