Precise Determination of the Deuteron Spin Structure at Low to Moderate Q² with CLAS and Extraction of the Neutron Contribution

Authors

The CLAS Collaboration
N. Guler, Old Dominion University
S E. KuhnFollow
Y. Prok, Old Dominion UniversityFollow
K. P. Adhikari, Old Dominion University
D. Adikaram, Old Dominion University
M. J. Amaryan, Old Dominion UniversityFollow
L. El Fassi, Old Dominion University
C. E. Hyde, Old Dominion UniversityFollow
A. Klein, Old Dominion UniversityFollow
L. B. Weinstein, Old Dominion UniversityFollow
Z. W. Zhao, Old Dominion University

Document Type

Article

Publication Date

2015

DOI

10.1103/PhysRevC.92.055201

Publication Title

Physical Review C

Volume

92

Issue

5

Pages

055201 (21 pages)

Abstract

We present the final results for the deuteron spin structure functions obtained from the full data set collected in 2000–2001 with Jefferson Lab's continuous electron beam accelerator facility (CEBAF) using the CEBAF large acceptance spectrometer (CLAS). Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.8 GeV were scattered from deuteron (¹⁵ND₃ ) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double-spin asymmetry, the virtual photon absorption asymmetry A^d₁ and the polarized structure function g^d₁ were extracted over a wide kinematic range (0.05GeV² < Q2 < 5GeV² and 0.9 GeV < W < 3GeV ). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions Aⁿ₁ and gⁿ₁ of the (bound) neutron, which are so far unknown in the resonance region, W < 2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations, as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x , a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the operator product expansion.

Comments

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Original Publication Citation

The CLAS Collaboration, Guler, N., Fersch, R. G., Kuhn, S. E., Bosted, P., Griffioen, K. A., . . . Zonta, I. (2015). Precise determination of the deuteron spin structure at low to moderate Q² with CLAS and extraction of the neutron contribution. Physical Review C, 92(5), 055201. doi:10.1103/PhysRevC.92.055201

ORCID

0000-0003-2243-6836 (Kuhn), 0000-0001-7282-8120 (Hyde),0000-0001-5416-2900 (Weinstein)

Repository Citation

The CLAS Collaboration; Guler, N.; Kuhn, S E.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; El Fassi, L.; Hyde, C. E.; Klein, A.; Weinstein, L. B.; and Zhao, Z. W., "Precise Determination of the Deuteron Spin Structure at Low to Moderate Q² with CLAS and Extraction of the Neutron Contribution" (2015). Physics Faculty Publications. 224.
https://digitalcommons.odu.edu/physics_fac_pubs/224