학술논문
Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from C12 and Al27
Document Type
article
Author
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; Zhamkochyan, S
Source
Physical Review C. 104(1)
Subject
Language
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.