First Determination of the 27Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement
Creators: name: QWeak Collaboration
name: Androic, D.
name: Armstrong, D. S.
name: Bartlett, K.
name: Beminiwattha, R. S.
name: Benesch, J.
name: Benmokhtar, F.
name: Birchall, J.
name: Carlini, R. D.
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: Elaasar, 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: Grimm, K.
name: Guo, F.
name: Hoskins, J. R.
name: Jones, D. C.
name: Jones, M. K.
name: Kargiantoulakis, M.
name: King, P. M.
name: Korkmaz, E.
name: Kowalski, S.
name: Leacock, J.
name: Leckey, J.
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: Mei, J.
name: Mesick, K. E.
name: Michaels, R.
name: Micherdzinska, A.
name: Mkrtchyan, A.
name: Mkrtchyan, H.
name: Narayan, A.
name: Ndukum, L. Z.
name: Nelyubin, V.
name: Nuruzzaman
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: Suleiman, R.
name: Tadevosyan, V.
name: Tobias, W. A.
name: Tvaskis, V.
name: Waidyawansa, B.
name: Wang, P.
name: Wells, S. P.
name: Wood, S. A.
name: Yang, S.
name: Zang, P.
name: Zhamkochyan, S.
name: Christy, M. E.
name: Horowitz, C. J.
name: Fattoyev, F. J.
name: Lin, Z.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the first measurement of the parity-violating elastic electron scattering asymmetry on 27Al. The 27Al elastic asymmetry is A_PV = 2.16 +- 0.11 (stat) +- 0.16 (syst) ppm, and was measured at =0.02357 +- 0.0001 GeV^2, = 7.61 +- 0.02 degrees, and = 1.157 GeV with the Qweak apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the 27Al neutron radius R_n = 2.89 +- 0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_n-R_p = -0.04 +- 0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the 27Al weak radius R_w = 3.00 +- 0.15 fm, and the weak skin thickness R_wk - R_ch = -0.04 +- 0.15 fm. The weak form factor at this Q^2 is F_wk = 0.39 +- 0.04.
description: Revised version after referee's comments and suggestions. Some improvements and clarification to the text, no changes to the figures, tables, results or conclusions. 7 pages, 3 figures, 3 tables