1. Measurement of the single-spin asymmetry $A_y^0$ in quasi-elastic $^3$He$^\uparrow$($e,e'n$) scattering at $0.4 < Q^2 < 1.0$ GeV$/c^2$
- Author
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Long, E., Zhang, Y. W., Mihoviloviv, M., Jin, G., Sulkosky, V., Kelleher, A., Anderson, B., Higinbotham, D. W., Sirca, S., Allada, K., Annand, J. R. M., Averett, T., Bertozzi, W., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chudakov, E., De Leo, R., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Hansen, J. -O., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kang, H., Katich, J., Khanal, H. P., King, P. M., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M., Shahinyan, A., Shoenrock, B., John, J. St., Subedi, R., Tobias, W. A., Tireman, W., Urciuoli, G. M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., and Zhu, L.
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FOS: Physical sciences ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment - Abstract
Due to the lack of free neutron targets, studies of the structure of the neutron are typically made by scattering electrons from either $^2$H or $^3$He targets. In order to extract useful neutron information from a $^3$He target, one must understand how the neutron in a $^3$He system differs from a free neutron by taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry $A_y^0$ is an ideal probe of such effects, as any deviation from zero indicates effects beyond plane wave impulse approximation. New measurements of the target single spin asymmetry $A_y^0$ at $Q^2$ of 0.46 and 0.96 (GeV/$c)^2$ were made at Jefferson Lab using the quasi-elastic $^3\mathrm{He}^{\uparrow}(e,e'n)$ reaction. Our measured asymmetry decreases rapidly, from $>20\%$ at $Q^2=0.46$ (GeV/$c)^2$ to nearly zero at $Q^2=0.96$ (GeV$/c)^2$, demonstrating the fall-off of the reaction mechanism effects as $Q^2$ increases. We also observed a small $��$-dependent increase in $A_y^0$ compared to previous measurements, particularly at moderate $Q^2$. This indicates that upcoming high $Q^2$ measurements from the Jefferson Lab 12 GeV program can cleanly probe neutron structure from polarized $^3$He using plane wave impulse approximation., 6 pages, 5 figures
- Published
- 2019
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