Abstract:
Neutrinos, tiny ghostlike particles billions of times lighter than atoms, are unique messengers to the distant, high-energy universe. Unlike cosmic rays and gamma rays, neutrinos are chargeless and weakly interacting, and arrive from high redshifts undeflected and unattenuated. High-energy neutrinos (>PeV) also probe physics at energy scales unachievable with terrestrial accelerators. However, the neutrino's low cross-sections and low fluxes pose experimental challenges, and requires enormous detectors. In this talk, I will focus on the Askaryan Radio Array (ARA) experiment. ARA is a detector deployed deep (~200m) at the South Pole. It is designed to find high-energy neutrinos by looking for the radio light emitted in neutrino interactions with the ice. I will highlight some of the latest results from the instrument, including a search for ultra-high energy neutrinos which produced the most stringent limit by an in-ice radio detector. I will highlight our ongoing work to develop reconstruction algorithms and to study interesting properties of the ice itself, such as the attenuation length. I will conclude by briefly discussing prospects and plans for extensions to even larger next generation detectors, such as RNO-G and IceCube-Gen2.
Ioana Maris and Steven Lowette