First Measurement of Hard Exclusive π−Δ++ Electroproduction Beam-Spin Asymmetries off the Proton
First Measurement of Hard Exclusive π−Δ++ Electroproduction Beam-Spin Asymmetries off the Proton
复制标题
首次测量质子外电产生束自旋不对称性
DOI：
10.1103/physrevlett.131.021901
复制
发表时间：
2023
影响因子：
8.6
通讯作者：
Baltzell, N. A.
中科院分区：
文献类型：
--
作者：
Diehl, S.;Trotta, N.;Joo, K.;Achenbach, P.;Akbar, Z.;Armstrong, W. R.;Atac, H.;Avakian, H.;Baashen, L.;Baltzell, N. A.
使用入射电子束和杰斐逊实验室的 CLAS12 光谱仪，基于束自旋不对称测量，提取了非极化氢靶硬排他电生产的极化横截面比。这项研究首次观察了深非弹性区域中的该通道，重点关注价态中的正向π介子运动学以及从 到 的光子虚拟性。该反应提供了一种了解核子夸克含量和跃迁广义部分子分布的新方法。提供了与硬排他和电生产的现有结果的比较，这显示了以跃迁广义部分子分布编码的激励机制对不对称性的明显影响。
The polarized cross-section ratiofrom hard exclusiveelectroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using aincident electron beam and the CLAS12 spectrometer at Jefferson Lab. The study, which provides the first observation of this channel in the deep-inelastic regime, focuses on very forward-pion kinematics in the valence regime, and photon virtualities ranging fromup to. The reaction provides a novel access to the-quark content of the nucleon and totransition generalized parton distributions. A comparison to existing results for hard exclusiveandelectroproduction is provided, which shows a clear impact of the excitation mechanism, encoded in transition generalized parton distributions, on the asymmetry.