Measurement of the Beam-Normal Single-Spin Asymmetry for Elastic Electron Scattering from $^{12}$C and $^{27}$Al
Creators: name: QWeak Collaboration
name: Androic, D.
name: Armstrong, D. S.
name: Asaturyan, A.
name: Bartlett, K.
name: Beminiwattha, R. S.
name: Benesch, J.
name: Benmokhtar, F.
name: Birchall, J.
name: Carlini, R. D.
name: Christy, M. E.
name: Cornejo, J. C.
name: Dusa, S. Covrig
name: Dalton, M. M.
name: Davis, C. A.
name: Deconinck, W.
name: Dowd, J. F.
name: Dunne, J. A.
name: Dutta, D.
name: Duvall, W. S.
name: Elassar, M.
name: Falk, W. R.
name: Finn, J. M.
name: Forest, T.
name: Gal, C.
name: Gaskell, D.
name: Gericke, M. T. W.
name: Gray, V. M.
name: Guo, F.
name: Hoskins, J. R.
name: Jones, D. C.
name: Kargiantoulakis, M.
name: King, P. M.
name: Korkmaz, E.
name: Kowalski, S.
name: Leacock, J.
name: Leckey, J. P.
name: Lee, A. R.
name: Lee, J. H.
name: Lee, L.
name: MacEwan, S.
name: Mack, D.
name: Magee, J. A.
name: Mahurin, R.
name: Mammei, J.
name: Martin, J. W.
name: McHugh, M. J.
name: Meekins, D.
name: Mesick, K. E.
name: Michaels, R.
name: Mkrtchyan, A.
name: Mkrtchyan, H.
name: Narayan, A.
name: Ndukum, L. Z.
name: Nuruzzaman
name: Nelyubin, V.
name: van Oers, W. T. H
name: Owen, V. F.
name: Page, S. A.
name: Pan, J.
name: Paschke, K. D.
name: Phillips, S. K.
name: Pitt, M. L.
name: Radloff, R. W.
name: Rajotte, J. F.
name: Ramsay, W. D.
name: Roche, J.
name: Sawatzky, B.
name: Seva, T.
name: Shabestari, M. H.
name: Silwal, R.
name: Simicevic, N.
name: Smith, G. R.
name: Solvignon, P.
name: Spayde, D. T.
name: Subedi, A.
name: Subedi, R.
name: Tadevosyan, V.
name: Tobias, W. A.
name: Waidyawansa, B.
name: Wang, P.
name: Wells, S. P.
name: Wood, S. A.
name: Zang, P.
name: Zhamkochyan, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, 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 $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. 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 (theta &lt; 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep.
description: Minor changes after refereeing; version as accepted for Physical Review C. Cosmetic changes to several figures, one author added. 22 pages, 8 figures