关于Pion诱导的Drell-Yan过程中的横向-旋转-依赖的亚齐图斯不对称的最终指南针结果
G D Alexeev1, M G Alexeev2,3, C Alice2,3
1Affiliated with an international laboratory covered by a cooperation agreement with CERN.
Physical review letters
|August 30, 2024
概括
在COMPASS协作测量了自旋依赖的Drell-Yan不对称性,使用 pion 束. 结果为核子横向动量依赖的部分分布函数和QCD预测提供了新的见解.
科学领域:
- 核物理 核物理 核物理
- 粒子物理学 粒子物理学
- 量子色态动力学 量子色态动力学
背景情况:
- 核子的横向动量依赖部分分布函数 (TMD PDF) 编码了关于其内部结构的关键信息.
- 了解TMD PDFs对于测试基本量子染色动力学 (QCD) 原则至关重要.
研究的目的:
- 为了测量Drell-Yan dimuon生产截面中的五个亚齐图斯调制.
- 为了探测核子TMD PDF,包括Sivers,横向性和形性.
- 调查TMD PDFs的普遍性,并测试QCD预测.
主要方法:
- 利用了2015年和2018年的COMPASS实验的数据.
- 采用了190GeV/c的先驱束,撞击了一个横向偏振的氨目标.
- 分析了dumion生产截面,以提取横向旋转依赖的亚齐图斯不对称性 (TSA).
主要成果:
- 提取了五个TSA的振幅,探测了领先的扭曲和下载的TMD PDF.
- 观察到的Sivers TSA与QCD预测的标志变化一致.
- 横向的TSA结果与Boer-Mulders函数的预期符号变化一致.
结论:
- 这些测量为核子TMD PDFs提供了新的约束.
- 结果支持基本的QCD预测,关于时间逆转奇特TMD的标志变化.
- 这项研究促进了对TMD PDF普遍性和核子结构的理解.
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