Precision measurements of $A_1^n$ in the deep inelastic regime

Journal Article · Fri May 01 00:00:00 EDT 2015 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2015.03.067· OSTI ID:1197802

Parno, D. S. ; Flay, D.; Posik, M.; Allada, K.; Armstrong, W.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. -P.; Choi, S.; Chudakov, E.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; Deng, X. ; Deur, A.; Dutta, C.; El Fassi, L.; Franklin, G. B.; Friend, M.; Gao, H.; Garibaldi, F.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Gomez, J.; Guo, L.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Hyde, C.; Ibrahim, H. F.; Jiang, X.; Jin, G.; Katich, J.; Kelleher, A.; Kolarkar, A.; Korsch, W.; Kumbartzki, G.; LeRose, J. J.; Lindgren, R.; Liyanage, N.; Long, E.; Lukhanin, A.; Mamyan, V.; McNulty, D.; Meziani, Z. -E.; Michaels, R.; Mihovilovič, M.; Moffit, B.; Muangma, N.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Nuruzzaman,; Oh, Y.; Peng, J. C.; Qian, X.; Qiang, Y.; Rakhman, A.; Riordan, S.; Saha, A.; Sawatzky, B.; Shabestari, M. H.; Shahinyan, A.; Širca, S.; Solvignon, P.; Subedi, R.; Sulkosky, V.; Tobias, W. A.; Troth, W.; Wang, D.; 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.

We have performed precision measurements of the double-spin virtual-photon asymmetry A₁ on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized ³He target. Our data cover a wide kinematic range 0.277 ≤ x ≤ 0.5480 at an average Q² value of 3.078 (GeV/c)², doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of an View the MathML source A₁ⁿ zero crossing near x=0.5. We find no evidence of a transition to a positive slope in (Δd+Δd¯)/(d+d¯) up to x=0.548.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Virginia, Charlottesville, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Contributing Organization: Jefferson Lab Hall A Collaboration; The Jefferson Lab Hall A Collaboration
• Grant/Contract Number: FG02-87ER40315; FG02-94ER40844; AC05-06OR23177; AC02-06CH11357; SC0014325
• OSTI ID: 1197802
• Alternate ID(s): OSTI ID: 1177738; OSTI ID: 1208854; OSTI ID: 1215513; OSTI ID: 1417864
• Report Number(s): JLAB-PHY-14-1899; DOE/OR/23177-3138; arXiv:1406.1207; S0370269315002427; PII: S0370269315002427
• Journal Information: Physics Letters B, Journal Name: Physics Letters B Vol. 744 Journal Issue: C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
spin structure functions
nucleon structure
parton distribution functions
polarized electron scattering