Strange Meson and Baryon Photoproduction

这项研究的目的是了解不同类型的夸克是如何结合形成短寿命粒子的。这些数据有助于物理学家更多地了解强作用力的基本理论，称为量子色动力学或简称QCD。这与原子核内的质子和中子结合在一起的力是相同的。这里研究的粒子有一个更重的夸克，叫做奇异夸克，它不是在一个稳定的原子核中孤立存在的。相反，这些粒子是利用伽马射线束（高能光子）和固定目标质子之间碰撞的能量产生的，称为光产生。寻找具有奇异夸克的粒子的原因是，具有重夸克的粒子的性质比只有轻夸克的粒子的性质更容易计算。尽管自然界中奇异粒子并不多，但它们帮助我们理解量子cd的理论计算，这也适用于稳定粒子和所有原子的原子核。这项研究更广泛的影响是促进技术进步和培养年轻科学家。技术的进步来自于建造新的粒子探测器，比如淋浴前量热计，它是杰斐逊实验室正在建造的CLAS12探测器的一部分。这个探测器测量撞击它的带电粒子的能量。新材料，如波长移位光纤，以及高速电子设备是该探测器技术的一部分，该探测器部分由美国国家科学基金会资助。年轻的科学家，包括本科生和研究生，都在帮助建造和测试探测器。该项目的毕业生已经在美国和国外的其他实验室、大学和私营企业工作。

The goal of this research is to learn how different types of quarks can combine to form short-lived particles. These data help physicists to understand more about the fundamental theory of the strong force, called quantum chromodynamics or QCD for short. This is the same force that binds together protons and neutrons inside the nucleus of an atom. The particles being studied here have a heavier quark, called the strange quark, which is not found isolated in a stable nucleus. Instead, these particles are created using the energy of a collision between a beam of gamma-rays (high-energy photons) and a stationary target of protons, called photoproduction. The reason to look for particles with the strange quark is that the properties of particles with heavy quarks are easier to calculate than are particles with only light quarks. Even though strange particles are not abundant in nature, they help us understand the theoretical calculations of QCD, which also apply to stable particles and the nuclei of all atoms.The broader impact of this research is to advance technology and to train young scientists. Advances in technology come from building new particle detectors, such as the Pre-shower Calorimeter which is part of the CLAS12 detector being constructed at Jefferson Lab. This detector measures the energy of charged particles that strike it. New materials, such as wavelength-shifting optical fibers, along with high-speed electronics are part of the technology used for this detector, which is funded in part by the NSF. Young scientists, both at the undergraduate and graduate levels, are helping to construct and test the detector. Past graduates of this program have gone on to work at other laboratories, universities and private industry, both in the USA and abroad.