Medium Energy Spin Physics

0072192 Hughes该基金资助的物理学项目旨在研究电弱和强相互作用。 从技术上讲，该计划的重点是使用极化电子束散射极化和非极化目标。 实验在弗吉尼亚州的杰斐逊实验室和加州的斯坦福大学线性加速器中心（SLAC）进行。 在SLAC，固定目标计划目前致力于电弱理论的精确测试。 通过在液氢靶中非极化电子散射高能量极化电子，我们能够在一个新的能量范围内进行电弱混合角的精确测试。 这个实验的结果将对新粒子和新相互作用的存在很敏感。 在杰斐逊实验室，固定目标计划的重点是极化氦-3对极化电子的散射，以了解中子内部自旋结构的信息。 在很宽的能量范围内测量中子自旋结构函数，可以测试基本的强相互作用和规则，并提供夸克对中子自旋的贡献的细节。

0072192Hughes The physics program funded by this grant is directed at the study of the electroweak and strong interactions. Technically, the program focuses on the use of polarized electron beams scattering off polarized and unpolarized targets. The experiments take place at the Jefferson Laboratory in Viriginia and the Stanford Linear Accelerator Center (SLAC) in California. At SLAC, the fixed target program is presently devoted to a precision test of the electroweak theory. By scattering polarized electrons at high energies off unpolarized electrons in a liquid hydrogen target, we are able to perform a precision test of the electroweak mixing angle in a new energy range. The results from this experiment will be sensitive to the existence of new particles and new interactions. At Jefferson Lab, the fixed target program is focused on the scattering of polarized electrons by polarized helium-3 in order to learn information on the internal spin structure of the neutron. Measurements of the neutron spin structure function over a wide range of energies allows for tests of fundamental strong interaction sum rules and provides details on the quark contribution to the neutron's spin.