Mapping the Spectrum of Light Quark Mesons and Gluonic Excitations with Linearly Polarized Photons

用线性偏振光子绘制光夸克介子和胶子激发的光谱

• 批准号: SAPPJ-2015-00024
• 负责人: Papandreou, Zisis
• 金额: $ 10.2万
• 依托单位: University of Regina
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614404
• 关键词: Mapping; Spectrum; Light; Quark; Mesons

Subatomic physics seeks to understand nature - and all its laws - at the most fundamental level, down to its elementary constituents and their interactions. Tremendous strides have been made in the last several decades, using accelerators and astrophysical observations, which have strengthened our conviction that the basic model, known as the Standard Model, is essentially a valid description of the subatomic world but not necessarily a complete one. Its success is based fundamentally on the concept of “asymptotic freedom,” which stipulates that the quarks, the most elemental particles, behave as free particles when their separation distance is small (such as in high energy collisions) so that analytical calculations of their weakened interactions can be made. However, when the quarks are bound together to form ordinary matter their interactions are so strong that they cannot be separated and cannot exist as individual free quarks. This is an experimental fact that imposes an additional aspect to the Standard Model, that of “quark confinement.” Its exact nature remains one of the outstanding problems in physics. In the confinement regime, where analytical calculations are not feasible, models have to be constructed with the freedom to adjust inputs, as required by experimental data, in order to learn about fundamental aspects of the problem at hand. For this to lead to a solid understanding of the true nature of confinement, high quality and reliable experimental data are absolutely necessary. The physics goal of the GlueX experiment, then, is to create and identify exotic forms of matter that, by their very nature, exhibit unique signatures among all other particles that will allow theoretical models of confinement to be tested in a most constraining way possible. This is a difficult task requiring experimental conditions that are just now becoming possible in accelerator and detector technology. In particular, the latter has benefited from the recent development of large photo sensors that are completely immune to magnetic fields present in these types of experiments. Our group played a defining role in guiding industry towards the development of these devices and they are now available commercially to the subatomic, medical and nuclear safety fields.

亚原子物理学试图在最基本的层面上理解自然及其所有定律，直到其基本成分及其相互作用。在过去的几十年里，利用加速器和天体物理学观测取得了巨大的进步，这加强了我们的信念，即被称为标准模型的基本模型本质上是对亚原子世界的有效描述，但不一定是完整的。它的成功基本上是基于“渐近自由”的概念，它规定夸克，最基本的粒子，当它们的分离距离很小时（如在高能碰撞中），表现为自由粒子，以便可以对它们的弱相互作用进行分析计算。然而，当夸克结合在一起形成普通物质时，它们的相互作用是如此之强，以至于它们不能被分离，也不能作为单独的自由夸克存在。这是一个实验事实，它给标准模型增加了一个额外的方面，即“夸克禁闭”。它的确切性质仍然是物理学中悬而未决的问题之一。 在约束制度，分析计算是不可行的，模型必须构建的自由调整输入，实验数据的要求，以了解手头的问题的基本方面。为了使人们更好地理解约束的真实性质，高质量和可靠的实验数据是绝对必要的。因此，GSTX实验的物理目标是创造和识别奇异形式的物质，就其本质而言，这些物质在所有其他粒子中表现出独特的特征，这将使约束的理论模型能够以最具约束力的方式进行测试。这是一项艰巨的任务，需要实验条件，而在加速器和探测器技术中，实验条件才刚刚成为可能。特别是，后者受益于最近开发的大型光电传感器，这些传感器完全不受这些类型实验中存在的磁场的影响。我们的团队在指导工业界开发这些设备方面发挥了决定性作用，这些设备现在已在亚原子、医疗和核安全领域商用。