Medium Energy Spin Physics

我们的研究小组是积极的研究，使用自旋极化光束和自旋极化目标，研究问题的基础和应用物理。目前，我们的主要重点是在寻找新的物理超越了标准模型，通过执行一个精确的测量宇称violationin极化电子散射的非极化电子在液态氢目标。 这项实验目前正在斯坦福大学直线加速器中心进行，最终将提供低能时电弱混合角的最精确测量。最近，我们的团队加入了布鲁克海文的星星合作组织。 这个大型对撞机物理实验目前正在调试一个程序，以散射具有高质心能量的自旋极化质子，以了解质子的内部自旋结构。 首要的问题是“胶子对质子的半自旋有多大贡献”。 预计未来几年的数据将首次直接揭示这一重要问题。 最后，我们的团队还在加州理工学院参与了自旋极化惰性气体的开发，即氦-3和氙-129，用于核物理和磁共振成像。

Our group is active in research that uses spin-polarized beams andspin-polarized targets to study issues in fundamental and applied physics.Currently, our primary focus is in the search for new physics beyond theStandard Model by performing a precision measurement of parity violationin the scattering of polarized electrons by unpolarized electrons in aliquid hydrogen target. The experiment, which is now being performed atthe Stanford Linear Accelerator Center, should eventually provide the mostprecise measurement of the electroweak mixing angle at low energies.Recently, our group has joined the Star Collaboration at Brookhaven. Thislarge collider physics experiment is presently commissioning a program toscatter spin-polarized protons with high center-of-mass energies in orderto learn about the internal spin structure of the proton. The primaryquestion being addressed is 'how much do gluons contribute to the proton'sone-half spin'. Data over the next few years is expected to give thefirst direct glimpse into this important question. Finally, our group isalso involved locally at Caltech in the development of spin-polarizednoble gas, namely helium-3 and xenon-129, for use in nuclear physics andmagnetic resonance imaging.