New Probes of the Ultra-Light Frontier

超轻前沿的新探测器

• 批准号: 1417295
• 负责人: Surjeet Rajendran
• 金额: $ 15万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417295&HistoricalAwards=false
• 关键词: New; Probes; Ultra; Light; Frontier

This award funds the research activities of Professor Surjeet Rajendran at the University of California, Berkeley. Physical laws often lead to new particles through which their effects are manifested on the natural world. For example, we experience the electric force because of the existence of particles like the electron and the proton that carry electric charge, with the force between them carried by the photon. Searches for particles is thus a fruitful way to discover new fundamental forces. It is important to search for such fundamental forces since they have the potential to significantly enhance our understanding of the origins of the laws of nature. They may also potentially enable us to interact with the natural world in dramatically new ways, potentially permitting advances as remarkable as the effects of electromagnetism on our daily lives. Many models of fundamental physics predict the existence of particles that have very small masses and also have very weak interactions with our world. In some cases, these particles can also be the dark matter of the universe. Their weak interactions can be overcome either with large systems or through precision technology. This project develops methods that use large astrophysical objects such as millisecond pulsars as well as precision laboratory techniques to significantly expand our reach into the parameter space of such particles.Professor Rajendran will develop new experimental approaches to detect ultra-light particles that interact very weakly with the standard model such as axions and dark photons. Such particles naturally emerge in many frameworks of physics beyond the standard model, and may even be the dark matter of the universe. The methods developed by Professor Rajendran include the use of the existence of the super-radiant instability of rotating systems to argue that the existence of certain kinds of light particles would cause the rapid spin-down of millisecond pulsars. Observations of such pulsars can therefore constrain these particles. Professor Rajendran will point out qualitatively new effects of dark photons emerging from their longitudinal modes. These effects have been overlooked in the literature and by incorporating them, he will show how existing experiments can parametrically extend their reach into the parameter space of such models. These gains also extend to the case where such dark photons constitute the dark matter of the Universe and he will invent techniques tailored to detect such dark matter. Professor Rajendran will also show how current experimental methodologies that have been developed to search for fundamental sources of CPT violation or a cosmologically preferred direction can also be used to search for certain kinds of light dark matter. The dark matter signal can be qualitatively different from the signals typically expected in these experiments and may permit ways to overcome the systematic limitations of such experiments. With the increasing costs of collider experiments, the future of particle physics may lie as much in non-collider experiments that can probe such hidden sectors that lie far in the ultra-violet.

该奖项资助加州大学伯克利分校Surjeet Rajendran教授的研究活动。物理定律经常导致新的粒子，它们的影响通过这些粒子在自然界中显现出来。例如，由于电子和质子等携带电荷的粒子的存在，我们体验到了电动力，它们之间的力由光子携带。因此，寻找粒子是发现新基本力的一种卓有成效的方式。寻找这样的基本力量是很重要的，因为它们有可能极大地增强我们对自然法起源的理解。它们还可能使我们能够以惊人的新方式与自然界互动，潜在地允许取得与电磁对我们日常生活的影响一样显著的进步。许多基本物理模型预测，存在质量非常小、与我们的世界相互作用非常弱的粒子。在某些情况下，这些粒子也可能是宇宙的暗物质。它们的弱相互作用可以通过大型系统或通过精密技术来克服。该项目开发了使用大型天体物理对象(如毫秒脉冲星)的方法以及精密实验室技术，以显著扩展我们对此类粒子参数空间的研究范围。Rajendran教授将开发新的实验方法，以探测与标准模型相互作用非常弱的超轻粒子，如轴子和暗光子。这种粒子自然出现在许多物理框架中，超出了标准模型，甚至可能是宇宙中的暗物质。Rajendran教授发展的方法包括利用旋转系统超辐射不稳定性的存在来论证某些类型的轻粒子的存在会导致毫秒脉冲星的快速自旋下降。因此，对这类脉冲星的观测可以限制这些粒子。Rajendran教授将定性地指出暗光子从其纵模中出现的新效应。这些影响在文献中被忽略了，通过结合它们，他将展示现有的实验如何以参数形式将它们的影响范围扩展到此类模型的参数空间。这些成果也延伸到这样的情况，即这样的暗光子构成了宇宙的暗物质，他将发明专门为探测这种暗物质而定制的技术。Rajendran教授还将展示目前为寻找CPT破坏的根本来源或宇宙学偏好方向而开发的实验方法如何也可以用于搜索某些类型的亮暗物质。暗物质信号在性质上可能与这些实验中通常预期的信号不同，并可能允许克服这些实验的系统限制的方法。随着对撞机实验成本的增加，粒子物理学的未来可能同样取决于非对撞机实验，这种实验可以探测到远位于紫外线中的这种隐藏扇区。