Jefferson Lab > CIO > IR
Privacy and Security Notice


Publication Information

Title Measurement of Single Spin Asymmetry in 3He{up-arrow}(e, e'K^±)X from a Transversely Polarized 3He Target
Authors Yuxiang Zhao
JLAB number JLAB-PHY-15-2332
LANL number (None)
Other number DOE/OR/23177-4091
Document Type(s) (Thesis) 
Supported by U.S. Naval Research: No
Supported by Jefferson Lab LDRD Funding: No
Funding Source: Nuclear Physics (NP)
A PHD thesis
Advisor(s) :
   Jian-Ping Chen (Jlab)
   zheng Zhao (University of Science and Technology)
Publication Abstract: Spin-dependent observables are a powerful tool to probe the internal structure of the nucleon and to study the dynamics of the strong interaction. Experimental study of the nucleon spin structure has provided us with many exciting and often surprising results. The so-called "spin crisis" in the 1980s revealed the limitation of naive quark-parton models and led to a worldwide effort to study the nucleon spin structure. However, this effort has been focused mainly on the nucleon's longitudinal spin structure. Recently, when the pioneer work revealed the significant role that transverse spin plays in understanding the full structure of the nucleon and in understanding the dynamics of the strong interaction, the study of the transverse spin structure became the new focus of the worldwide effort. Jefferson Lab (JLab) is located at Newport News, VA, US. It is equipped with the continuous electron beam accelerator facility (CEBAF) and four experimental halls: A, B, C and D. The accelerator can provide a continuous electron beam (2 ns beam bunch) with high polarization (up to ? 90%) and high current (up to ~ 200?A) for fixed target experiments in all experimental halls. Hall A consists of two standard high-resolution spectrometers (HRS): left HRS (LHRS) and right HRS (RHRS). Another spectrometer, the BigBite spectrometer, can be installed on request by certain experiments. The experiment E06-010 ("Transversity Experiment") at JLab Hall A is the first measurement of the transverse spin structure of the neutron using a transversely polarized 3He target and a 5.89 GeV incident electron beam. The experiment measured target single spin asymmetries (SSA) and beam-target double-pin asymmetries (DSA) in semi-inclusive deep-inelastic scattering (SIDIS) and in deep-inelastic scattering (DIS) processes. It also collected inclusive hadron (pion, kaon and proton) production data parasitically. The scattered electrons were detected in the BigBite spectrometer with associated detectors while the hadrons were detected with the LHRS which had excellent particle identification capabilities. In this dissertation, the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target will be discussed. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematical range of 0.1=0.64 GeV/c, will also be discussed. The asymmetries strongly depend on the flavor of hadron. The pi+ and pi? asymmetries are opposite in sign, demonstrated a strong flavor dependency similar to what has been observed in polarized p{uparrow} +p collisions. These measurements have provided important inputs to the world's data set on the investigation of transverse spin structure of the nucleon. They also laid the foundation for the future high precision study of the subject in the 12-GeV JLab and a future electron-ion collider.
Experiment Numbers: E06-010
Group: Hall A
Document: pdf
Accepted Manuscript:
Supporting Documents:
Supporting Datasets: