Preliminary results of a precision measurement of the neutron d2: Probing the Lorentz color force

The quantity d2, related to a twist-three matrix element, is a measure of the average restoring Lorentz color force experienced by a quark inside a polarized nucleon after it is struck by a virtual photon in electron Deep Inelastic Scattering (DIS). With its information encoded in both spin structure functions g1 and g2 in the quark valence region at large Bjorken x, this confining local force is a result of the remnant di-quark system attracting the struck quark. While bag-and chiralsoliton-model calculations for the neutron d2 are consistent with those of lattice Quantum Chromodynamics (QCD), current experimental data differ by approximately two standard deviations from those theoretical results. To address this issue, the experiment E06-014 was carried out from February to March of 2009 at Jefferson Lab. It consisted of measuring doublespin asymmetries and the total cross section by scattering a longitudinally polarized electron beam from a longitudinally or transversely polarized 3He target, allowing ...