Probing for N*s with Linearly Polarized Photons in Hall B of JLab

由一束线偏振光子提供的探测器使人们能够在光核反应中获得几个可观测到的东西，否则这些东西是无法测量的。光子束的偏振轴破坏了反应的方位对称性，从而在微分截面中引入了方位依赖关系。这种关于角度相关性的附加信息打开了测量一系列可观测物质的大门，这些可观测物质只有通过一束线偏振光子才能获得；因此，它对光子-核子反应的性质提供了重要的约束。这样的极化观测对于提取宽重叠重子共振的自旋/宇称是必要的。爱达荷州立大学的两名博士生将分析JLab B厅的g8b数据集。他们的论文主题将主要集中在寻找分别通过Rho介子或超子通道衰变的重子共振(N*S)。PI一直非常积极地与拉丁美洲的核物理学家协调研究工作。在过去的六年里，他获得了五项NSF奖学金，旨在促进北美和南美机构的教职员工和学生之间的对话。通过这些努力，他寻求加强现有联系，并在国际核物理界的广泛范围内建立新的联系。此外，这种学术关系将进一步加强我们各自大陆之间的科学研究计划。国际和平基金会希望利用这个NSF奖作为一个平台，为这些更广泛的影响活动吸引更多的赠款资金。

The probe afforded by a beam of linearly-polarized photons allows one to gain access to several observables in photonucleon reactions, which otherwise would not be measureable. This polarization axis of the photon beam breaks the azimuthal symmetry of the reaction, thereby introducing an azimuthal dependence in the differential cross section. This additional information on the angular dependence opens the door to the measurement of a host of observables which are accessible only with a beam of linearly-polarized photons; consequently it provides important constraints on the nature of the photon-nucleon reaction. Such polarization observables are necessary for extracting the spin/parity of the broadly overlapping baryon resonances. Two PhD students at Idaho State University will analyze the g8b data set from Hall B of JLab. Their thesis topics will primarily focus on the search for baryon resonances (N*s) that decay though either the rho meson or hyperon channel, respectively.The PI has been very active in coordinating research efforts with nuclear physicists in Latin America. Over the past six years, he has been awarded five NSF grants, which serve to promote dialog among faculty members and students of North American and South American institutions. Through these efforts, he seeks to strengthen existing links and forge new ones within the broad scope of the international nuclear physics community. Such academic relationships, moreover, will further serve to strengthen the scientific research program between our respective continents. The PI expects to use this NSF award as a platform towards attracting additional grant money for these broader impact activities.