Toward Solving Cosmic Particle Mysteries with Neutrinos and Gamma Rays

该奖项资助了宾夕法尼亚州立大学Kohta Murase教授的研究活动。最近，被称为冰立方的千兆吨级中微子探测器发现了高能地外中微子，这为粒子天体物理学开辟了一个新的前沿。中微子是幽灵般的中性粒子，可以从宇宙的密集区域逃逸；因为它们与其他形式的物质相互作用非常弱，所以它们不会偏转地到达地球，因此往往会直接指向产生它们的遥远天体物理来源。冰立方最近发现的这些高能中微子的起源是该领域的一个新谜团，解决这个问题不仅可以让我们了解微物理学和来源的机制，还可以获得关于宇宙射线起源这一古老谜团的重要线索。更一般地说，这一发现使我们能够利用中微子作为中微子性质、暗物质和其他形式的基础物理的探测器。Murase教授研究的一个主要目标是通过结合来自中微子和伽马射线的数据，通过粒子产生和传播的理论计算，来解决这些新旧问题。这项研究是跨学科的，包括天体物理学和粒子物理学的主题，并将理论思想直接与实验和观测数据联系起来。因此，这项研究将通过促进基础科学的进步来促进国家利益。预计该项目还将产生更广泛的重大影响。它将涉及并因此为参与这项研究的研究生提供培训，粒子天体物理学的关键概念将在高中和社区大学的教育工作者中传播。从技术上讲，这项研究的关键因素之一是战略性的多信使方法，在这种方法中，对不同天体粒子（中微子、伽马射线和宇宙射线）的预测面临着数据。通过复杂的计算，包括所有相关的微物理过程，PI将测试天体粒子起源的各种模型，并提取对极端天体物理物体的源物理的基本见解。测量的中微子、伽玛射线和宇宙射线背景之间的多信使联系将被检查，并且不能被伽玛射线直接探测到的宇宙射线加速器的源类也将被研究。这项研究的结果应该对下一代中微子和伽马射线探测器的设计有用。

This award funds the research activities of Professor Kohta Murase at the Pennsylvania State University. A new frontier in particle astrophysics has just opened up with the recent discovery of high-energy extra-terrestrial neutrinos by the the Gigaton-scale neutrino detector known as IceCube. Neutrinos are ghostlike neutral particles which can escape from dense regions in the Universe; because they interact so weakly with other forms of matter, they arrive undeflected at Earth and thus tend to point directly back to the distant astrophysical sources that produced them. The origin of these high-energy neutrinos recently discovered by IceCube is a new mystery in the field, and solving this problem would allow us not only to understand the microphysics and mechanisms of the sources but also to obtain important clues about an old mystery, the origin of cosmic rays. More general, this discovery allows us to utilize neutrinos as probes of neutrino properties, dark matter, and other forms of fundamental physics. A major goal of Professor Murase's research is to address these new and old problems through combinations of data coming not only from neutrinos but also from gamma rays, through theoretical calculations of particle production and propagation. This research is interdisciplinary, including topics in astrophysics and particle physics and connecting theoretical ideas directly to experimental and observational data. As a result, this research will advance the national interest by promoting the progress of fundamental science. This project is also envisioned to have significant broader impacts. It will involve and thereby provide training to graduate students involved in this research, and key concepts of particle astrophysics will be disseminated among educators at high schools and community colleges.More technically, one of the key ingredients in this research is the strategic multi-messenger approach in which predictions for different astroparticles (neutrinos, gamma rays, and cosmic rays) are confronted with data. With sophisticated calculations including all relevant microphysical processes, the PI will test various models for the astroparticle origins and extract fundamental insights into the source physics of extreme astrophysical objects. The multi-messenger connection among the measured neutrino, gamma-ray, and cosmic-ray backgrounds will be examined, and source classes of cosmic-ray accelerators that cannot be directly probed by gamma rays will also be studied. The results of this study should be useful for the design of proposed next-generation neutrino and gamma-ray detectors.