Experimental studies at low $Q^2$ of the spin structure of the nucleon at Jefferson Lab

Abstract

We summarize the experimental program of Jefferson Lab that studies the nucleon spin structure at low $Q^2$. This program completes the precise experimental mapping of the nucleon spin structure functions $g_1(\nu ,Q^2)$ and $g_2(\nu ,Q^2)$ and their moments started at SLAC, CERN and DESY at high $Q^2$, and continued at Jefferson Lab at intermediate $Q^2$. The results presented cover the domain where Chiral Effective Field Theory ($\chi$EFT) should describe the strong interaction. They provide a comprehensive set of benchmark measurements for $\chi$EFT. The preliminary conclusion is that nucleon spin structure data are still challenging for $\chi$EFT in spite of the notable improvements in these calculations.

arXiv comment7 pages, 2 figures. Contribution to the proceedings of the 9th International workshop on Chiral Dynamics (PoS CD18)

References in corpus (11)

• Adler Function, Bjorken Sum Rule, and the Crewther Relation to Order alpha_s^4 in a General Gauge Theory
• High precision determination of the $Q^2$-evolution of the Bjorken Sum
• Nucleon spin structure and pQCD frontier on the move
• Determination of the Proton Spin Structure Functions for 0.05 < Q^2 < 5 GeV^2 using CLAS
• Moments of the Spin Structure Functions g_1^p and g_1^d for 0.05 < Q^2 < 3.0 GeV^2
• Gold-plated moments of nucleon structure functions in baryon chiral perturbation theory
• Precise Determination of the Deuteron Spin Structure at Low to Moderate $Q^2$ with CLAS and Extraction of the Neutron Contribution
• Nucleon spin structure at low momentum transfers
• Measurement of the Q^2 Dependence of the Deuteron Spin Structure Function g_1 and its Moments at Low Q^2 with CLAS
• 3He Spin-Dependent Cross Sections and Sum Rules
• Measurement of Target and Double-spin Asymmetries for the $\vec{e}\vec{p}\to e{\pi }^{+}(n)$ Reaction in the Nucleon Resonance Region at Low $Q^2$