Any Light Particle Searches (ALPS)

多个天文观测已经确定，宇宙中大约85%的物质不是由已知粒子组成的。破译这种所谓的暗物质的性质对宇宙学、天体物理学和高能粒子物理学具有根本的重要性。粒子物理学中最令人兴奋的任务之一是寻找超越粒子物理学标准模型的新粒子。标准模型的扩展不仅预测了质量超过电弱尺度（约1000亿电子伏特，eV）的新粒子，而且还预测了所谓的WISP（弱相互作用亚电子伏特粒子）。最著名的WISP候选者是轴子，它被引入来解释量子色动力学中电荷宇称（CP）破坏的微小性，并且也是宇宙中暗物质成分的主要候选者。类似地，轴子状粒子，即自旋为1的光粒子，被称为“隐藏扇区光子”，似乎在标准模型实际嵌入弦论中时自然出现。因此，这些弱相互作用的光粒子是否存在是一个重要而基本的问题。任何光粒子搜索（ALPS）实验将为学生和博士后科学家提供机会，从激光和光学，电子和反馈控制系统，真空和低温，计算方法和数据分析算法开发，大规模探测器调试和操作，暗物质物理学和宇宙学等不同学科发展科学技能。所需的技术是为地面和空间引力波探测器开发的技术的副产品。该奖项所支持的工作将建立在这些投资的基础上，并将允许继续开发高性能的光学技术和设备，这些技术和设备在激光和光学工业中具有商业应用。德国DESY正在开发的ALPS实验是一项“光穿透墙壁”的研究，在那里光子被投射转换成弱相互作用的光粒子，这些光粒子不受阻碍地穿过不透明的墙壁并转换（部分）回到墙后的光子。这些粒子中最著名的是轴子，它需要强磁场才能转化为光子。ALPS产品组合中的其他粒子包括隐藏扇区光子，它们与电磁场线性耦合，不需要静磁场。计划中的ALPS@DESY实验是对轴子和隐藏扇区光子的领先背景独立搜索。ALPS灵敏度的提高将首次使纯粹的实验室实验能够以与恒星演化或太阳搜索的极限相竞争或上级的水平来探测轴光子耦合。该实验只依赖于基本的光子-轴子相互作用，而不是太阳模型或关于暗物质的假设。该奖项反映了NSF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。

Multiple astronomical observations have established that about 85% of the matter in the universe is not made of known particles. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. One of the most exciting quests in particle physics is the search for new particles beyond the Standard Model of particle physics. Extensions of the standard model predict not only new particles with masses above the electroweak scale (about 100 billion electron-volts, eV), but also so-called WISPs (Weakly Interacting Sub-eV Particles). The most famous WISP candidate is the axion, which has been introduced to explain the smallness of Charge-Parity (CP) violation in Quantum ChromoDynamics and which turns out to also be a prime candidate for a constituent of the dark matter in the universe. Similarly, axion-like particles, light spin 1 particles called "hidden sector photons," seem to occur naturally in realistic embeddings of the standard model into string theory. It is therefore an important and fundamental question whether any of these weakly-interacting light particles exists. The Any Light Particle Search (ALPS) experiment will give students and postdoctoral scientists the opportunity to develop scientific skills from a diverse set of disciplines spanning lasers and optics, electronics and feedback control systems, vacuum and cryogenics, computational methods and data analysis algorithm development, large-scale detector commissioning and operation, dark-matter physics and cosmology. The required technologies are spin-offs of technologies which were developed for ground and space-based gravitational-wave detectors. The work supported by this award would build on these investments and would allow continued development of high performance optical techniques and devices which have commercial applications in the laser and optics industries.The ALPS experiment under development at DESY in Germany is a 'light-shining-through-walls' search, where photons are projected to be converted into weakly interacting light particles which pass unimpeded through an opaque wall and convert (in part) back to photons behind the wall. The most famous of these particles are axions which require a strong magnetic field to convert to photons. Other particles which fall within the ALPS portfolio include hidden-sector photons which couple linearly to the electromagnetic field and do not require a static magnetic field. The planned ALPS@DESY experiments are the leading background-independent searches for axions and hidden sector photons. The improved sensitivity of ALPS would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar searches. The experiment only depends on the fundamental photon-axion interaction and not on solar models nor on assumptions about dark matter.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.