Document Type

Article

Publication Date

2019

DOI

10.1016/j.physletb.2018.12.065

Publication Title

Physics Letters B

Volume

789

Pages

426-431

Abstract

The beam spin asymmetry of the exclusive pseudoscalar channel →ep→e′p′η was measured for the first time in the deep-inelastic regime (W > 2 GeV/c2 and Q2 > 1 GeV2 /c2) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q2, xB, −t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin ϕ moments is a clear indication of a substantial contribution to the polarized cross-section from transversely polarized virtual photons. In the framework of generalized parton distributions (GPDs) this contribution is expressed via longitudinal-transverse interference between chiral-even and chiral-odd GPDs. The experimental results are compared to the existing theoretical models demonstrating the sensitivity to the product of chiral-odd and chiral-even GPDs and provide new constraints to the existing GPD parameterizations.

Comments

© 2019 The Authors. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Original Publication Citation

Zhao, B., Kim, A., Joo, K., Bedlinskiy, I., Kim, W., Kubarovsky, V., . . . Zhao, Z. W. (2019). Measurement of the beam spin asymmetry of →ep→e′p′η in the deep-inelastic regime with CLAS. Physics Letters B, 789, 426-431. doi:10.1016/j.physletb.2018.12.065

ORCID

0000-0003-2243-6836 (Kuhn)

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