Semi-Inclusive πº Target and Beam-Target Asymmetries From 6 GeV Electron Scattering With CLAS

Authors

S. Koirala, Old Dominion University
S E. KuhnFollow
D. Adikaram, Old Dominion University
M. J. Amaryan, Old Dominion UniversityFollow
S. Bültmann, Old Dominion UniversityFollow
G. Charles, Old Dominion University
Gail Dodge, Old Dominion UniversityFollow
N. Guler, Old Dominion University
M. Khachatryan, Old Dominion University
A. Klein, Old Dominion UniversityFollow
Y. Prok, Old Dominion UniversityFollow
L. B. Weinstein, Old Dominion UniversityFollow
Z. W. Zhao, Old Dominion University

Document Type

Article

Publication Date

2018

DOI

10.1016/j.physletb.2018.06.014

Publication Title

Physics Letters B

Volume

782

Pages

662-667

Abstract

We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic ¹⁴NH₃ target, and extracted double and single target spin asymmetries for ep → e′π⁰X in multidimensional bins in four-momentum transfer (1.0 < Q² < 3.2 GeV²), Bjorken-x (0.12 < x < 0.48), hadron energy fraction (0.4 < z < 0.7), transverse pion momentum (0 < P_T < 1.0 GeV), and azimuthal angle ϕ_h between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x and P_T, which provide access to transverse-momentum distributions of longitudinally polarized quarks. The double spin asymmetries depend weakly on P_T. The sin 2ϕ_h moments are zero within uncertainties, which is consistent with the expected suppression of the Collins fragmentation function. The observed sin ϕ_h moments suggest that quark gluon correlations are significant at large x.

Comments

© The Authors. This is an open access article under the CC BY license.

Original Publication Citation

Jawalkar, S., Koirala, S., Avakian, H., Bosted, P., Griffioen, K. A., Keith, C., . . . Zhao, Z. W. (2018). Semi-inclusive π⁰ target and beam-target asymmetries from 6 gev electron scattering with CLAS. Physics Letters B, 782, 662-667. doi:10.1016/j.physletb.2018.06.014

ORCID

0000-0003-2243-6836 (Kuhn), 0000-0003-1582-2376 (Dodge), 0000-0001-5416-2900 (Weinstein)

Repository Citation

Koirala, S.; Kuhn, S E.; Adikaram, D.; Amaryan, M. J.; Bültmann, S.; Charles, G.; Dodge, Gail; Guler, N.; Khachatryan, M.; Klein, A.; Prok, Y.; Weinstein, L. B.; and Zhao, Z. W., "Semi-Inclusive πº Target and Beam-Target Asymmetries From 6 GeV Electron Scattering With CLAS" (2018). Physics Faculty Publications. 233.
https://digitalcommons.odu.edu/physics_fac_pubs/233