A measurement of the neutron electric form factor at very large momentum transfer using polarized electrons scattering from a polarized helium-3 target.

摘要

Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q2 and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized 3He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. GEn was measured to be 0.0242 +/- 0.0020(stat) +/- 0.0061(sys) and 0.0247 +/- 0.0029(stat) +/- 0.0031(sys) at Q2 = 1.7 and 2.5 GeV2, respectively.