Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from and

D Androić, DS Armstrong, A Asaturyan, K Bartlett… - Physical Review C, 2021 - APS
D Androić, DS Armstrong, A Asaturyan, K Bartlett, RS Beminiwattha, J Benesch…
Physical Review C, 2021APS
We report measurements of the parity-conserving beam-normal single-spin elastic scattering
asymmetries B n on C 12 and Al 27, 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 C 12 and provide a first measurement on Al 27. The
experiment utilized the Q weak 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 Q …
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries on and , 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 on and provide a first measurement on . The experiment utilized the apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average laboratory scattering angle for both targets was , and the average for both targets was 0.024 37 ( GeV). The asymmetries are ppm for and ppm for . The results are consistent with theoretical predictions, and are compared to existing data. When scaled by , the dependence of all the far-forward angle () data from to can be described by the same slope out to GeV. Larger-angle data from other experiments in the same range are consistent with a slope about twice as steep.
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