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Title: Measurement of the proton $$A_1$$ and $$A_2$$ spin asymmetries. Probing Color Forces

The Spin Asymmetries of the Nucleon Experiment (SANE) measured the proton spin structure function $$g_2$$ in a range of Bjorken x, 0.3 < x < 0.8, where extraction of the twist-3 matrix element $$d_2^p$$ (an integral of $$g_2$$ weighted by $x^2$) is most sensitive. The data was taken from $Q^2$ equal to 2.5 $GeV^2$ up to 6.5 $GeV^2$. In this polarized electron scattering off a polarized hydrogen target experiment, two double spin asymmetries, A∥ and A⊥ were measured using the BETA (Big Electron Telescope Array) Detector. BETA consisted of a scintillator hodoscope, gas Cerenkov counter, lucite hodoscope and a large lead glass electromagnetic calorimeter. With a unique open geometry, a threshold gas Cerenkov detector allowed BETA to cleanly identify electrons for this inclusive experiment. A measurement of $$d_2^p$$ is compared to lattice QCD calculations.
Authors:
 [1]
  1. Temple University, Philadelphia, PA (United States)
Publication Date:
OSTI Identifier:
1190860
Report Number(s):
JLAB-PHY--15-2094; DOE/OR/23177--3454
DOE Contract Number:
AC05-06OR23177
Resource Type:
Thesis/Dissertation
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS