1. Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from C12 and Al27
- Author
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Androić, D, Armstrong, DS, Asaturyan, A, Bartlett, K, Beminiwattha, RS, Benesch, J, Benmokhtar, F, Birchall, J, Carlini, RD, Christy, ME, Cornejo, JC, Dusa, S Covrig, Dalton, MM, Davis, CA, Deconinck, W, Dowd, JF, Dunne, JA, Dutta, D, Duvall, WS, Elaasar, M, Falk, WR, Finn, JM, Forest, T, Gal, C, Gaskell, D, Gericke, MTW, Gray, VM, Guo, F, Hoskins, JR, Jones, DC, Kargiantoulakis, M, King, PM, Korkmaz, E, Kowalski, S, Leacock, J, Leckey, JP, Lee, AR, Lee, JH, Lee, L, MacEwan, S, Mack, D, Magee, JA, Mahurin, R, Mammei, J, Martin, JW, McHugh, MJ, Meekins, D, Mesick, KE, Michaels, R, Mkrtchyan, A, Mkrtchyan, H, Narayan, A, Ndukum, LZ, Nelyubin, V, Nuruzzaman, van Oers, WTH, Owen, VF, Page, SA, Pan, J, Paschke, KD, Phillips, SK, Pitt, ML, Radloff, RW, Rajotte, JF, Ramsay, WD, Roche, J, Sawatzky, B, Seva, T, Shabestari, MH, Silwal, R, Simicevic, N, Smith, GR, Solvignon, P, Spayde, DT, Subedi, A, Subedi, R, Suleiman, R, Tadevosyan, V, Tobias, WA, Tvaskis, V, Waidyawansa, B, Wang, P, Wells, SP, Wood, SA, Zang, P, and Zhamkochyan, S
- Subjects
Clinical Research ,nucl-ex - Abstract
We report measurements of the parity-conserving beam-normal single-spinelastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained withan electron beam polarized transverse to its momentum direction. Thesemeasurements add an additional kinematic point to a series of previousmeasurements 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 energyof 1.158 GeV. The average lab scattering angle for both targets was 7.7degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppmfor $^{12}$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 arecompared to existing data. When scaled by Z/A, the Q-dependence of all thefar-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can bedescribed by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data fromother experiments in the same Q range are consistent with a slope about twiceas steep.
- Published
- 2021