Beam Spin Asymmetry Measurements of Deeply Virtual π⁰ Production with CLAS12

Authors

The CLAS Collaboration
A. Kim
S. Diehl
K. Joo
V. Kubarovsky
P. Achenbach
Z. Akbar
J. S. Alvarado
Whitney R. Armstrong
H. Atac
H. Avakian
C. Ayerbe Gayoso
L. Barion
M. Battaglieri
I. Bedlinskiy
B. Benkel
A. Bianconi
A. S. Biselli
M. Bondi
M. Zureck
et al.

Document Type

Article

Publication Date

2024

DOI

10.1016/j.physletb.2024.138459

Publication Title

Physics Letters B.

Volume

849

Pages

138459 (1-6)

Abstract

The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive π⁰ production in a wide kinematic region with the photon virtualities Q² up to 6.6 GeV²and the Bjorken scaling variable 𝓍_B in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD E¯_T, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the nucleon's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities.

Rights

© 2024 The Authors.

This article is published under a Creative Commons Attribution 4.0 International (CC BY 4.0) License.

Data Availability

Article states: Data will be made available on request.

Original Publication Citation

Kim, A., Diehl, S., Joo, K., Kubarovsky, V., Achenbach, P., Akbar, Z., Alvarado, J. S., Armstrong, W. R., Atac, H., Avakian, H., Ayerbe Gayoso, C., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Bianconi, A., Biselli, A. S., Bondi, M., Bossù, F., . . . Zurek, M. (2024). Beam spin asymmetry measurements of deeply virtual π⁰ production with CLAS12. Physics Letters B, 849, 1-6, Article 138459. https://doi.org/10.1016/j.physletb.2024.138459

ORCID

0000-0003-2086-2807 (Hattawy), 0000-0002-1265-2212 (Hauenstein), 0000-0003-2243-6836 (Kuhn), 0000-0002-3598-4594 (Pandey), 0000-0001-6345-2360 (Poudel)

Repository Citation

The CLAS Collaboration; Kim, A.; Diehl, S.; Joo, K.; Kubarovsky, V.; Achenbach, P.; Akbar, Z.; Alvarado, J. S.; Armstrong, Whitney R.; Atac, H.; Avakian, H.; Ayerbe Gayoso, C.; Barion, L.; Battaglieri, M.; Bedlinskiy, I.; Benkel, B.; Bianconi, A.; Biselli, A. S.; Bondi, M.; Zureck, M.; and et al., "Beam Spin Asymmetry Measurements of Deeply Virtual π⁰ Production with CLAS12" (2024). Physics Faculty Publications. 831.
https://digitalcommons.odu.edu/physics_fac_pubs/831