Investigating the Electromagnetic Structure of the Nucleon and Light Nuclei at Jefferson Lab

该研究项目的主要目标是继续在弗吉尼亚州纽波特纽斯的托马斯杰斐逊国家加速器设施（“杰斐逊实验室”）的合作努力，该实验室专门针对使用高能电子束探测核子的结构。这项工作将与杰斐逊实验室A厅的超级大咬光谱仪（SBS）合作完成。在此资助期间，杰斐逊实验室将从过去的过渡“升级期”阶段出现-将束流能量从6 GeV升级到12 GeV -并开始使用专门为更高能量设计和建造的设备。该提案包括一项计划，以确保持续的科学贡献和学生培训与早期运行的A厅实验（实验不仅关注核子结构，而且关注轻核的结构-特别是triton三核子系统），但主要的重点仍然是与一系列具体的后期相关的准备/开发项目，运行SBS实验，将探测核子结构功能在非常高的动量转移。这个项目的各个方面的驱动物理目标都与提高对从大约1到几个费米（强子自由度最合适）的相对较大距离尺度的“强（非微扰）QCD”政权过渡到更短距离尺度的“微扰QCD”政权的理解有关。

The primary objective of this research project is to continue collaborative efforts at the Thomas Jefferson National Accelerator Facility ("Jefferson Lab") in Newport News, Virginia, which are specifically aimed at probing the structure of the nucleon using a high energy electron beam. This work will be accomplished in collaboration with the Super BigBite Spectrometer (SBS) Collaboration in Hall A at Jefferson Lab. During this grant period, Jefferson Lab will be emerging from the past transition "upgrade period" phase - having upgraded the beam energy from 6 GeV to 12 GeV - and beginning to utilize equipment specifically designed and built for the higher energy. This proposal includes a plan to ensure continued scientific contributions and student training with the early-running Hall A experiments (experiments focusing not only on nucleon structure, but also on that of light nuclei - particularly the triton three-nucleon system), but with primary emphasis remaining on preparation/development projects associated with a series of specific later-running SBS experiments that will probe nucleon structure functions at very high momentum transfers. The driving physics goals of all aspects of this project are related to improving understanding of the transition from the 'strong (non-perturbative) QCD' regime of relatively large distance scales of approximately 1 to a few fermis (where hadronic degrees of freedom are most appropriate), to the 'perturbative QCD' regime of much shorter distance scales.