The detection of ultra-high energy (UHE, >10 PeV) neutrinos via detectors designed to utilize the Askaryan effect has been a long-time goal of the astroparticle physics community. The Askaryan effect describes radio-frequency (RF) radiation from high-energy cascades. When a UHE neutrino initiates a cascade, cascade properties are imprinted on the radiation. Thus, observed radiation properties must be used to reconstruct the UHE neutrino event. Analytic Askaryan models have three advantages when used for UHE neutrino reconstruction. First, cascade properties may be derived from the match between analytic function and observed data. Second, analytic models minimize computational intensity in simulation packages. Third, analytic models can be embedded in firmware to enhance the real-time sensitivity of detectors. We present a fully analytic Askaryan model in the time-domain for UHE neutrino-induced cascades in dense media that builds upon prior models in the genre. We then show that our model matches semi-analytic parameterizations used in Monte Carlo simulations for the design of IceCube-Gen2. We find correlation coefficients greater than 0.95 and fractional power differences < 5% between the the fully analytic and semi-analytic approaches.
Observation of In-ice Askaryan Radiation from High-Energy Cosmic Rays
University of Chicago（芝加哥大学）；University of Kansas（堪萨斯大学）；The Ohio State University（俄亥俄州立大学）；Chiba University（千叶大学）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）；National Taiwan University（台湾大学）；Universite Libre de Bruxelles（布鲁塞尔自由大学）；University of Maryland（马里兰大学）
阿斯卡里安射电阵列（英语：Askaryan Radio Array，ARA）是一个位于南极的超高能中微子望远镜，由一组射电天线组成，旨在探测冰中中微子相互作用产生的阿斯卡里安辐射。目前，该实验有五个台站在运行，自2012年以来已分阶段部署。这篇文章的重点是从2013-2016年在两个ARA站（A2和A3）中寻找中微子扩散通量的发展。在水平极化和垂直极化的两个搜索信道中的每一个中，在一个站中预期$\sim 0.01-0.02$事件的背景。根据对两个台站四年的分析，预期对超高能中微子通量的新限制比ARA以前设定的限制提高了约两倍。ARA的五站数据集的预计灵敏度开始与其他中微子望远镜在$10^{10.5}\,$ GeV附近的高能量竞争。
