Collaborative Research: PP2PP, a Comprehensive Elastic proton-proton Scattering Experiment at RHIC

该奖项涵盖研究生和本科生在布鲁克海文国家实验室的相对论重离子对撞机进行PP2PP实验的研究。国际pp2pp合作的目标是全面测量质子-质子弹性散射，最终在一次实验中覆盖一个广泛的、尚未探索的能量（从50到500 GeV）和动量转移（从0.006 GeV^2到1.3 GeV^2）领域。第一次使用极化质子束的数据运行将在2001年秋季进行。将使用两个罗马锅探测器站，每个手臂上一个。在接下来的几年里，将再增加两个站点和中央跟踪。通过实验，并与已有的反质子-质子弹性散射数据进行比较，研究远距离pp相互作用的螺旋结构，研究交换机制，并将其与多胶子交换的QCD计算联系起来。pp弹性散射中有趣的倾斜结构将以高统计量获得。在非常小的动量转移时，PP2PP将测量绝对横截面和前向散射振幅的细节。2003年以后，RHIC机器的特殊调谐将允许最低可达动量转移达到库仑状态。PP2PP实验的小规模使其非常适合本科生参与构建、数据采集和数据分析的各个方面。

The award covers graduate student and undergraduate student researchwith the PP2PP experiment at the Relativistic Heavy Ion Collider atthe Brookhaven National Laboratory. The goal of the internationalPP2PP collaboration is the comprehensive measurement ofproton-proton elastic scattering, eventually covering a wide, andunexplored, domain in energy (from 50 to 500 GeV) and momentumtransfer (from 0.006 GeV^2 to 1.3 GeV^2) within a single experiment.The first data run with polarized proton beams will take place inthe Fall 2001. Two Roman pot detector stations will be used, one ineach arm. Two more stations plus central tracking will be added infollowing years. With the experiment and by comparing with existingantiproton-proton elastic scattering data, the helicity structure ofthe long-distance pp interaction will be investigated, the exchangemechanisms will be studied and connected to QCD calculations ofmulti-gluon exchanges. The intriguing dip structure in pp elasticscattering will be accessible with high statistics. At very smallmomentum transfers PP2PP will measure absolute cross sections andthe details of the forward scattering amplitude. Beyond 2003, aspecial tune of the RHIC machine will allow the lowest accessiblemomentum transfer to reach into the Coulomb regime. The small scaleof the PP2PP experiment makes it ideally suited for participation byundergraduate students in all aspects of construction, data taking,and data analysis.