Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction ${{}^3\mathrm{He}}^{\uparrow }\left(e,e^{\text{'}}\right)X$

Journal Article · Tue Jul 01 00:00:00 EDT 2014 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.113.022502· OSTI ID:1136703

Katich, J.; Qian, X.; Zhao, Y. X.; Allada, K.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. -P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E. ; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, C.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H. -J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z. -E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J. C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qiang, Y.; Rakhman, A.; Ransome, R. D.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L. -G.; Tobias, A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wang, Y.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y.; Zhang, Y. -W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.

We report the first measurement of the target single-spin asymmetry in deep-inelastic scattering from the inclusive reaction ³He^↑(e,e')X on a ³He gas target polarized normal to the lepton plane. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7<2.9 GeV, 1.0²<4.0 GeV² and 0.16<0.65. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-³He cross section ratios. The measured neutron asymmetries are negative with an average value of (-1.04+/-0.38)×10^-2 for invariant mass W>2 GeV, which is non-zero at the 2.75 sigma level. Theoretical calculations, which assume two-photon exchange with quasi-free quarks, predict a neutron asymmetry of O(10^-4) when both photons couple to one quark, and O(10^-2) for the photons coupling to different quarks. Our measured asymmetry agrees both in sign and magnitude with the prediction that uses input based on the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1136703
• Report Number(s): JLAB-PHY-13-1802; DOE/OR/23177-2898; arXiv:1311.0197; PRLTAO
• Journal Information: Physical Review Letters, Vol. 113, Issue 2; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English