Highlights of JLab Neutron (3He) Spin Program

Conference · Wed Jul 01 00:00:00 EDT 2009 · AIP conference proceedings

DOI:https://doi.org/10.1063/1.3203303· OSTI ID:980901

Chen, Jian-ping

Nucleon spin structure has been an active, exciting and intriguing subject of interest for the last three decades. Recent precision spin-structure data from Jefferson Lab have significantly advanced our knowledge of nucleon structure at low Q2. In particular, it has improved our understanding of spin sum rules and higher-twist effects. First, results of neutron spin sum rules and polarizabilities in the low to intermediate Q2 region are presented. Comparison with theoretical calculations, in particular with Chiral Perturbation Theory (ChPT) calculations, are discussed. Surprising disagreements of ChPT calculations with experimental results on the generalized spin polarizability, delta_LTⁿ, were found. Results of precision measurements of the g2 structure function to study higher-twist effects are presented. The data indicate a significant higher-twist (twist-3 or higher) effect. The second moment of the spin structure functions and the twist-3 matrix element d2 results were extracted. The high Q2 result was compared with a Lattice QCD calculation. Finally, other neutron spin structure results, such as the resonance data for quark-hadron duality study and a precision measurement of the neutron spin asymmetry in the valence quark (high-x) region are briefly discussed.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 980901
• Report Number(s): JLAB-PHY-09-1045; DOE/OR/23177-0949; JLAB-EXP-94-010; TRN: US1003966
• Journal Information: AIP conference proceedings, Vol. 1155; Conference: Spin Structure At Long Distance, 12-13 Mar 2009, Jefferson Lab, Newport News, Virginia
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ACCURACY
ASYMMETRY
DATA
DISTANCE
DUALITY
MATRIX ELEMENTS
NEUTRONS
NUCLEONS
PERTURBATION THEORY
POLARIZABILITY
QUANTUM CHROMODYNAMICS
QUARKS
RESONANCE
SPIN
STRUCTURE FUNCTIONS
SUM RULES
VALENCE