Document Type
Article
Department/Program
Physics
Journal Title
Physical Review C
Pub Date
7-2021
Volume
104
Issue
1
Abstract
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries Bn on 12C and 27Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of Bn on 12C and provide a first measurement on 27Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average laboratory scattering angle for both targets was 7.7∘, and the average Q2 for both targets was 0.024 37 GeV2 (Q=0.1561 GeV). The asymmetries are Bn=−10.68±0.90(stat)±0.57(syst) ppm for 12C and Bn=−12.16±0.58(stat)±0.62(syst) ppm for 27Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q dependence of all the far-forward angle (θ<10∘) data from 1H to 27Al can be described by the same slope out to Q≈0.35 GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep.
Recommended Citation
Androic, D.; Armstrong, David S.; and et al., Measurement of the Beam-normal Single-spin Asymmetry for Elastic Electron Scattering from ^12C and ^27Al (2021). Physical Review C, 104(1).
https://doi.org/10.1103/PhysRevC.104.014606
DOI
https://doi.org/10.1103/PhysRevC.104.014606
Publisher Statement
This work is made available for educational and personal use only. Copyright is credited to the authors. Any other uses should be directed to the publisher.
