Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction $^{3}\mathrm{He}^{\uparrow}(e,e')X$
J. Katich, X. Qian, Y. X. Zhao, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, M. Canan, … 展开作者
J. Katich, X. Qian, Y. X. Zhao, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, M. Canan, G. D. Cates, C. Chen, J. -P. Chen, W. Chen, K. Chirapatpimol, E. Chudakov, E. Cisbani, J. C. Cornejo, F. Cusanno, M. M. Dalton, W. Deconinck, C. W. de Jager, R. De Leo, X. Deng, A. Deur, H. Ding, P. A. M. Dolph, C. Dutta, D. Dutta, L. El Fassi, S. Frullani, H. Gao, F. Garibaldi, D. Gaskell, S. Gilad, R. Gilman, O. Glamazdin, S. Golge, L. Guo, D. Hamilton, O. Hansen, D. W. Higinbotham, T. Holmstrom, J. Huang, M. Huang, H. F. Ibrahim, M. Iodice, X. Jiang, G. Jin, M. K. Jones, A. Kelleher, W. Kim, A. Kolarkar, W. Korsch, J. J. LeRose, X. Li, Y. Li, R. Lindgren, N. Liyanage, E. Long, H. -J. Lu, D. J. Margaziotis, P. Markowitz, S. Marrone, D. McNulty, Z. -E. Meziani, R. Michaels, B. Moffit, C. Muńoz Camacho, S. Nanda, A. Narayan, V. Nelyubin, B. Norum, Y. Oh, M. Osipenko, D. Parno, J. C. Peng, S. K. Phillips, M. Posik, A. J. R. Puckett, Y. Qiang, A. Rakhman, R. D. Ransome, S. Riordan, A. Saha, B. Sawatzky, E. Schulte, A. Shahinyan, M. H. Shabestari, S. Širca, S. Stepanyan, R. Subedi, V. Sulkosky, L. -G. Tang, A. Tobias, G. M. Urciuoli, I. Vilardi, K. Wang, Y. Wang, B. Wojtsekhowski, X. Yan, H. Yao, Y. Ye, Z. Ye, L. Yuan, X. Zhan, Y. Zhang, Y. -W. Zhang, B. Zhao, X. Zheng, L. Zhu, X. Zhu, X. Zong
备注：
This is the final edited version as published in PRL
本文首次测量了极化$^3$ He气体靶上包含反应$^3$ He $^{\uparrow}\left(e,e' \right)X$的深度非弹性散射中靶-正常单自旋不对称性。假设时间反演不变性，这种不对称性在玻恩近似中严格为零，但如果包括双光子交换贡献，则可以是非零的。该实验在杰斐逊实验室使用5.89 GeV电子束进行，涵盖了$1.7 < W < 2.9$ GeV、$1.0<Q^2<4.0$ GeV、$^2$和$0.16<x<0.65$的范围。利用有效核子极化和测量的质子- $^3$ He截面比提取中子不对称性。测量的中子不对称性是负的，对于不变质量$W>2$ GeV，其平均值为$(-1.09 \pm 0.38) \times10^{-2}$，在$2.89σ$水平上为非零。我们测得的不对称性同意在符号和幅度与双光子交换模型预测，使用从半包容性深非弹性散射获得的Sivers横向动量分布的输入。
英文摘要：
We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction $^3$He$^{\uparrow}\left(e,e' \right)X$ on a polarized $^3$He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be non-zero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of $1.7 < W < 2.9$ GeV, $1.0<Q^2<4.0$ GeV$^2$ and $0.16<x<0.65$. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-$^3$He cross section ratios. The measured neutron asymmetries are negative with an average value of $(-1.09 \pm 0.38) \times10^{-2}$ for invariant mass $W>2$ GeV, which is non-zero at the $2.89σ$ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.
Physics Department, Brookhaven National Laboratory（布鲁克海文国家实验室）；RIKEN BNL Research Center, Brookhaven National Laboratory（布鲁克海文国家实验室）；Joint Institute for Nuclear Research（联合核研究所）
Transverse Single-Spin Asymmetry for Inclusive and Diffractive Electromagnetic Jets at Forward Rapidity in $p^{\uparrow}$+p Collisions at $\sqrt{s} = 200$ GeV and $510$ GeV at STAR
Single/Double-Spin Asymmetry Measurements of Semi-Inclusive Pion Electroproduction on a Transversely Polarized 3He Target through Deep Inelastic Scattering
Study of Two-Photon Exchange via the Beam Transverse Single Spin Asymmetry in Electron-Proton Elastic Scattering at Forward Angles over a Wide Energy Range
Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude
Transverse Spin Structure of the Nucleon through Target Single Spin Asymmetry in Semi-Inclusive Deep-Inelastic $(e,e^\prime π^\pm)$ Reaction at Jefferson Lab
杰斐逊实验室（JLab）12 GeV的能量升级提供了一个黄金机会，可以对质子和中子在价夸克区域的横向自旋和横向动量相关结构进行精确研究。在本文中，我们重点讨论了最近批准的中子实验，作为JLab计划的精度研究的一个例子。新实验将使用11和8.8 GeV电子束，在深度非弹性散射运动学中，从40 cm长的横向极化$^3$ He靶半包容性电产生带电π介子，对靶单自旋不对称性（SSA）进行精确测量。这个新的符合实验在大厅A将采用一个新提出的螺线管光谱仪（SoLID）。大接收谱仪和高偏振光度将通过方位角依赖性提供关于中子的Collins、Sivers和Pretzelocity不对称性的精确四维（$x$、$z$、$P_T$和$Q^2$）数据。实验室中2 $π$全方位角覆盖对于控制系统不确定性至关重要。从这个实验的结果，当结合质子柯林斯不对称性测量和柯林斯碎裂功能确定的e $^+$ e $^-$碰撞数据，将允许夸克味分离，以实现10%的准确度确定张量电荷的d夸克。提取的Sivers和pretzelocity不对称性将为理解夸克轨道角动量和核子自旋之间以及夸克自旋和核子自旋之间的相关性提供重要信息。
Beam-Target Double Spin Asymmetry A_LT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He-3 Target at 1.4<Q^2<2.7 GeV^2
