RUI: Photons Acting Like Fermions: Search for Violations of the Spin Statistics Theorem Using Sr Atoms

RUI：光子的行为像费米子：使用 Sr 原子搜索自旋统计定理的违反情况

• 批准号: 1607762
• 负责人: Jennie Guzman
• 金额: $ 32.07万
• 依托单位: California State University, East Bay Foundation, Inc.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1607762&HistoricalAwards=false
• 关键词: RUI; Photons; Acting; Like; Fermions

Fundamental particles of nature can be characterized by their individual properties such as electric charge, mass, and spin. This last property, spin angular momentum, appears to determine whether a particle falls into one of two general categories. Particles with integer valued spin are called "bosons", and those with half-integer valued spin are called "fermions." The boson or fermion distinction has a remarkable effect on the statistical behavior of particle groups. For example, an unlimited number of bosons (such as photons) can occupy the same quantum state, but only a single fermion (such as an electron) can occupy a specific state.  These differences in properties result in vastly different macroscopic behaviors. The distinction between a boson an a fermion is important for the structure of the periodic table of the elements, the degree to which atoms interact with each other during collisions, and even the stability of matter in everyday objects. This research aims to answer the question: are there exceptions to the general rule which links spin to the characterization of a particle as a boson or fermion?  Researchers at California State University East Bay will probe the fundamental properties of light (a spin-1 particle) and explore whether it, a boson, ever exhibits any fermion-like behavior.  Such a discovery would provide a new direction for the theoretical development of the basic axioms of physics and supply an essential ingredient to a more fundamental view of the world.Experimental searches for violations of the spin statistics theorem (SST) test fundamental assumptions of quantum field theory, such as local Lorentz invariance.  For this research, researachers will constrain the SST-forbidden two-photon transition rate between the ground J=0 and excited J'=1 states in atomic strontium.  A two-photon transition between these two states would possess total angular momentum J=1, which is an exchange-antisymmetric (fermionic) state forbidden by the SST.  This new experimental search is motivated by an expected three orders of magnitude increase in sensitivity over previous searches.  This increase is made possible by using laser-cooled strontium atoms and separate detection and excitation regions, reducing the leading systematic effect, scattered light. This work will take place at an undergraduate institution and will directly engage undergraduate students in hands-on research.  This research program will especially benefit the diverse student body at California State University East Bay, where nearly two-thirds of students are women, over sixty percent are first-generation college students, and over seventy-five percent are underrepresented minorities.

自然的基本颗粒可以以其各个特性（例如电荷，质量和自旋）为特征。最后一个特性，即旋转角动量，似乎决定了粒子是否属于两个一般类别之一。具有整数旋转的颗粒称为“玻色子”，具有半均值自旋的颗粒称为“费米子”。玻色子或费米的区别对粒子群的统计行为具有显着影响。例如，一个无限数量的玻色子（例如照片）可以占据相同的量子状态，但是只有一个fermion（例如电子）才能占据特定状态。这些性质的差异导致巨大的宏观行为。玻色子和费米对元素的结构，原子在碰撞期间相互相互作用的程度，甚至物质在每天对象中的稳定性都很重要。这项研究旨在回答以下问题：一般规则是否有旋转与粒子作为玻色子或费米的表征的例外？加利福尼亚州立大学东湾的研究人员将探测光的基本特性（自旋1粒子），并探索它是否表现出任何类似费米的行为。这样的发现将为物理基本公理的理论发展提供新的方向，并提供对世界更基本观点的重要感应。实验搜索违反旋转统计定理（SST）测试量子场理论的基本假设，例如lorentz lorentz lorentz的不变性。在这项研究中，同学将限制地面j = 0和激发j'= 1个原子延髓状态之间的SST验证的两光子过渡速率。这两个状态之间的两光子转变可能会导致总角动量j = 1，这是SST禁止的交换 - 抗对称（费米子）状态。这种新的实验搜索与以前的搜索相比，灵敏度提高了三个数量级的融合。通过使用激光冷却的锶原子和单独的检测和兴奋区，可以减少领先的系统效应（散射光），从而使这种增加成为可能。这项工作将在本科机构进行，并将直接与本科生进行动手研究。该研究计划将特别受益于加利福尼亚州立大学东湾的潜水员学生团体，那里的学生中有近三分之二是女性，超过60％的是第一代大学生，而超过75％的学生是代表人数不足的少数群体。