1. Precision measurements of A1n in the deep inelastic regime
- Author
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S. Choi, Mustafa Canan, Kalyan Allada, H. Yao, M. Friend, A. Deur, Wouter Deconinck, Nuruzzaman, J. P. Chen, B. Sawatzky, F. Garibaldi, M. H. Shabestari, G. D. Cates, S. K. Nanda, Yujie Qiang, R. Subedi, A. Camsonne, N. Muangma, A. Shahinyan, Vincent Sulkosky, O. Glamazdin, Z. Ye, B. E. Norum, V. Mamyan, J. Huang, R. A. Lindgren, J. J. LeRose, Olfred Hansen, Bogdan Wojtsekhowski, X. Deng, X. Zhan, W. Troth, Y. Zhang, D. Flay, A. Lukhanin, B. Moffit, G. Jin, M. Posik, Douglas Higinbotham, C. Dutta, X. Zheng, Zein-Eddine Meziani, Diana Parno, William A. Tobias, D. McNulty, Arijit Saha, P. Solvignon, J. Gomez, Jen-Chieh Peng, S. Golge, Chunhui Chen, S. Širca, Haiyan Gao, Y. X. Ye, Wolfgang Korsch, L. Yuan, X. Jiang, Whitney Armstrong, G. Kumbartzki, B. Zhao, Yiyang Zhang, William Bertozzi, Yingxiao Wang, Amrendra Narayan, Joseph M. Katich, Shalev Gilad, C. W. de Jager, G. B. Franklin, M. M. Dalton, T. Holmstrom, S. Riordan, D. Wang, Ronald Gilman, R. Michaels, Abdurahim Rakhman, L. Guo, E. Long, M. Mihovilovič, A. Kelleher, Vladimir Nelyubin, Young Do Oh, H. F. Ibrahim, E. Chudakov, A. Kolarkar, Nilanga Liyanage, T. Averett, C. E. Hyde, F. Cusanno, Fatiha Benmokhtar, X. Yan, Xin Qian, and L. El Fassi
- Subjects
Quantum chromodynamics ,Physics ,Nuclear physics ,Quark ,Nuclear and High Energy Physics ,Proton ,media_common.quotation_subject ,Up quark ,Neutron ,Parton ,Deep inelastic scattering ,Asymmetry ,media_common - Abstract
We have performed precision measurements of the double-spin virtual-photon asymmetry A 1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3 He target. Our data cover a wide kinematic range 0.277 ≤ x ≤ 0.548 at an average Q 2 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 A 1 n zero crossing near x = 0.5 . We find no evidence of a transition to a positive slope in ( Δ d + Δ d ¯ ) / ( d + d ¯ ) up to x = 0.548 .
- Published
- 2015