Forward Meson Production and Spin Asymmetries at RHIC

质子的高能结构和高能质子-质子相互作用依赖于底层夸克和胶子的自旋和角动量。 布鲁克海文相对论重离子对撞机（RHIC）提供了独特的工具，使研究质子成分的自旋在极化质子碰撞中的作用成为可能。RHIC是第一台高能极化质子对撞机，实验人员可以在对撞前准备高能质子的自旋取向。这些极化质子碰撞研究的星星探测器的质心能量高达500 GeV。当相对论质子碰撞时，它们会产生高能碎片，包括中性π介子、等离子体和粒子喷流。正是在非常靠前的区域，粒子的产生对质子自旋的方向最敏感。这项研究涉及测量相对论质子-质子碰撞中的前向碎片。特别是，横向自旋的依赖性进行了研究，使用铅玻璃量热计称为FMS，这是位于前区的星星探测器。 我们的目标是描述这种生产对事件运动学的依赖性。 我们测试QCD相关的预测如何自旋的质子与自旋的夸克，以及如何这可以修改可观察到的横截面。该赠款支持收集新的RHIC FMS数据和分析该数据。 我们的目标是更好地理解关于质子性质的最基本的问题。质子被理解为由夸克和胶子组成，它们被强相互作用结合在一起。 这个项目研究夸克自旋在质子结构中所起的作用。这项调查涉及的建设和正在进行的操作的FMS热量计在星星探测器在布鲁克海文国家实验室。 FMS设备可供星星中的所有其他合作者使用。超过500名星星合作者从事各种物理主题的工作，其中许多都是通过FMS的存在而增强的。 这项研究涉及参与的本科生谁协助制造的电子和分析数据的实验。它涉及研究生，无论是那些支持这个补助金和其他人谁使用我们的仪器。我们还介绍感兴趣的初中或高中学生到我们的工作，并在可能的情况下让他们参与。

Proton high energy structure and the high energy proton-proton interaction depend on the spin and angular momentum of the underlying quarks and gluons. Unique tools are available at the Brookhaven Relativistic Heavy Ion Collider (RHIC), which make it possible to study the role of the spin of the proton constituents in polarized proton collisions. RHIC is the first high energy polarized proton collider, where experimentalists can prepare the spin orientation of high energy protons before they collide. These polarized proton collisions are studied in the STAR detector with center of mass energies up to 500 GeV. When relativistic protons collide, they produce high energy fragments including neutral pions, etas and jets of particles. It is in the very forward region where particle production is most sensitive to the orientation of the proton spin. This research involves measurement of forward fragments in relativistic proton-proton collisions. In particular, transverse spin dependence is studied using a lead-glass calorimeter called the FMS, which is located in the forward region of the STAR detector. The goal is to characterize the dependence of this production on event kinematics. We test QCD related predictions of how the spin of the proton correlates with the spin of quarks and how this can modify the observable cross sections. This grant supports the collection of new RHIC FMS data and the analysis of that data. The objective is better understanding of the most basic questions about the nature of the proton.The proton is understood to consist of quarks and gluons bound together by the strong force. This project investigates the role quark spin plays in the structure of the proton. This investigation involves the construction and ongoing operation of the FMS calorimeter in the STAR detector at Brookhaven National Lab. The FMS apparatus is available to all the other collaborators in STAR. The over 500 STAR collaborators work on a diverse range of physics topics, many of which are enhanced by the presence of the FMS. This research involves participation of undergraduate students who assist in fabrication of electronics and in analysis of data from the experiment. It involves graduate students, both those supported by this grant and others who use our apparatus. We also introduce interested middle school or high school students to our work and involve them where possible.