ALPS II Science Runs and Upgrades

天文测量表明，宇宙中近85%的物质是未知的粒子，确定这种“暗物质”的性质是对粒子物理学标准模型之外的新物理学进行最广泛搜索的基础之一。任意光粒子搜索（ALPS）是一个光穿墙（LSW）实验，通过搜索在墙的一侧光子的消失和在另一侧重新出现来探测光子（光）与非标准模型粒子的相互作用。对这种相互作用的观察将有助于发现暗物质的本质。该合同支持佛罗里达大学的ALPS II小组对该项目的首次科学运行进行最终调试和数据分析。该奖项为学生提供了多样化的培训机会，使他们能够在激光和光学、电子、真空和低温等学科中发展独特的可转移技能。ALPS II实验位于德国汉堡的DESY实验室，是世界上最灵敏的LSW实验。该装置由两根120米长的拉直的5.3特斯拉HERA偶极磁体组成，每根磁体位于一个防光墙的两侧。一个光学腔用于将墙一侧的功率提高到1MW，而另一个腔用于放大墙另一侧的光子再创造过程。这个实验装置提供了超过12个数量级的灵敏度提高，比以前的搜索相互作用，使光子变成低质量粒子，反之亦然。这些潜在的低质量粒子包括类轴子粒子，它们的标量对应物，以及隐藏的光子，它们可能是无所不在的暗物质的组成部分，甚至是唯一的组成部分。ALPS II的搜索技术仅依赖于光子和假设的非标准模型粒子之间的基本相互作用，并探索了最近天文和其他观测所青睐的参数空间。结果是一个很大程度上独立于模型的搜索，没有关于恒星演化的假设，也没有任何特定的暗物质粒子。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Astronomical measurements indicate that nearly 85% of the matter in the Universe is yet unknown particles and determining the nature of this “dark matter” is the basis for one of the most extensive searches for new physics beyond the Standard Model of particle physics. The Any Light Particle Search (ALPS) is a light shining through wall (LSW) experiment that probes interactions of photons (light) with non-Standard Model particles via a search for the disappearance of photons on one side of a wall and to reemerge on the other. The observation of such an interaction would provide a discovery of the nature of the dark matter. This award supports the ALPS II group at the University of Florida to perform final commissioning and data analysis of the first science runs of the project. The award provides diverse training opportunities for students to develop unique and transferrable skills in disciplines spanning lasers and optics, electronics, vacuum and cryogenics. The ALPS II experiment, located at the DESY laboratory in Hamburg, Germany, is the world’s most sensitive LSW experiment. The apparatus consists of two 120m-long strings of straightened 5.3 Tesla HERA dipole magnets on each side of a light-tight wall. An optical cavity is used to build up the power on one side of the wall to up to 1MW, while a second cavity is used to amplify the photon re-creation process on the other side of the wall. This experimental setup provides a more than 12 order of magnitude improvement in sensitivity over previous searches for interactions that turn photons into low-mass particles, and vice versa. These potential low-mass particles include axion-like particles, their scalar counterparts, as well as hidden-sector photons, that may contribute to, or even exclusively form, the omnipresent dark matter. The ALPS II search technique depends only on proposed fundamental interactions between photons and postulated non-standard-model particles and explores a parameter space that has been favored by recent astronomical and other observations. The result is a largely model-independent search with no assumptions about stellar evolution nor any specific dark matter particle.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.