The Coherent BREMS Project: Baryon Resonance and Exotic Meson Search

我们试图在早期工作的基础上，通过探测带有极化光子的质子来研究共振重子态的性质。构成G8运行第一阶段的一系列实验于2001年夏天(6/04/01-8/13/01)在杰斐逊实验室B厅进行。这些实验利用了相干韧致辐射产生的一束线偏振光子，这是杰斐逊实验室首次使用这样的探测器。八国集团第二阶段会议将于2005年夏季举行(2005年6月20日至2005年8月31日)。G8的科学目的是提高对核子中夸克自由度的基本对称性、入射光子与目标核子之间宇称交换的性质以及电磁反应中相关奇异性产生的机制的理解。利用标记和准直的线偏振光子的高质量光束，以及Hall-B光谱仪的几乎完全的角覆盖，我们试图提取在1.10到2.25GeV的光子能量范围内产生矢量介子和介子的微分截面和偏振观测值。这项拟议的研究已经产生了两个博士和两个硕士论文，以及一个NSF研究生研究奖学金。这项提案的很大一部分资金将为一名博士生提供支持。

We seek to build upon our earlier work and investigate the nature of resonant baryon states by probing protons with polarized photons. The set of experiments forming the first phase of the g8 run took place in the summer of 2001 (6/04/01 - 8/13/01) in Hall B of Jefferson Lab. These experiments made use of a beam of linearly-polarized photons produced through coherent bremsstrahlung and represent the first time such a probe has been employed at Jefferson Lab. The second phase of g8 will take place in the summer of 2005 (6/20/05 - 8/31/05). The scientific purpose of g8 is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. With the high-quality beam of the tagged and collimated linearly-polarized photons and the nearly complete angular coverage of the Hall-B spectrometer, we seek to extract the differential cross sections and polarization observables for the photoproduction of vector mesons and kaons at photon energies ranging between 1.10 and 2.25 GeV. This proposed research has already yielded two PhD and two Master's theses, as well as one NSF Graduate Research Fellowship. A good part of the funding for this proposal will provide support for one PhD student.