Extraction of the Nuetron Electric Form Factor from Measurements of Inclusive Double Spin Asymmetries

Background: Measurements of the neutron charge form factor, GnE , are challenging because the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting GnE with different targets and techniques provides an important test of our handling of these effects. Purpose: The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of 1(GeV/c)2 . This technique has very different systematic uncertainties than traditional exclusive measurements and thus serves as an independent check of whether nuclear effects have been taken into account correctly. Method: The inclusive quasielastic reaction 3→He(→e,e′) was measured at Jefferson Laboratory. The neutron electric form factor, GnE , was extracted at Q2=0.98(GeV/c)2 from ratios of electron-polarization asymmetries measured for two orthogonal target spin orientations. This Q2 is high enough that the sensitivity to GnE is not overwhelmed by the neutron magnetic contribution, and yet low enough that explicit neutron detection is not required to suppress pion production. Results: The neutron electric form factor, GnE , was determined to be 0.0414 ± 0.0077 (stat) ± 0.0022 (syst) , providing the first high-precision inclusive extraction of the neutron\u27s charge form factor. Conclusions: The use of the inclusive quasielastic 3→He(→e,e′) with a four-momentum transfer near 1(GeV/c)2 has been used to provide a unique measurement of GnE . This new result provides a systematically independent validation of the exclusive extraction technique results and implies that the nuclear corrections are understood. This is contrary to the proton form factor where asymmetry and differential cross section measurements have been shown to have large systematic differences

Determination of the Titanium Spectral Function From (e, e\u27p) Data

The E12-14-012 experiment, performed in Jefferson Lab Hall A, has measured the (e,e′p) cross section in parallel kinematics using a natural titanium target. In this paper, we report the analysis of the dataset obtained in different kinematics for our solid natural titanium target. Data were obtained in a range of missing momentum and missing energy between 15 ≲ pm ≲ 250  MeV/c and 12 ≲ Em ≲ 80  MeV, respectively, and using an electron beam energy of 2.2 GeV. We measured the reduced cross section with ∼7% accuracy as a function of both missing momentum and missing energy. Our Monte Carlo simulation, including both a model spectral function and the effects of final-state interactions, satisfactorily reproduces the data