Physical Review Letters
Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25 of 3.21 and 4.32 GeV2/c(2), with an absolute precision of about 10(-5). Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at < Q(2)> = 5 GeV2/c(2). Combining d(2)(n) and a newly extracted twist-4 matrix element f(2)(n), the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 30 MeV/fm in magnitude.
Posik, Matthew, et al. "Precision Measurement of the Neutron Twist-3 Matrix Element d 2 n: Probing Color Forces." Physical review letters 113.2 (2014): 022002.