Toward Solving Cosmic Particle Mysteries with Neutrinos and Gamma Rays

该奖项资助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级中微子探测器发现了高能地外中微子，开辟了粒子天体物理学的一个新前沿。中微子是幽灵般的中性粒子，可以从宇宙中的密集区域逃逸；因为它们与其他形式的物质相互作用非常弱，它们到达地球时不会偏转，因此往往会直接指向产生它们的遥远的天体物理来源。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，解决这个问题不仅可以让我们了解源的微物理和机制，还可以获得关于一个古老的谜团--宇宙射线的起源的重要线索。更广泛地说，这一发现允许我们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。村上春树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，来解决这些新老问题。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，并将理论想法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。更严格地说，这项研究的关键成分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。通过包括所有相关微物理过程的复杂计算，PI将测试各种天体粒子起源模型，并提取对极端天体物理对象的源物理的基本见解。将研究测量的中微子、伽马射线和宇宙射线背景之间的多信使联系，并研究无法直接用伽马射线探测的宇宙射线加速器的源类别。这项研究的结果应该对拟议的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.