3:30–4:30 pm ERC 161
Steven Prohira (University of Kansas) "Ultrahigh energy neutrino detection...with radar?"
Detection of ultrahigh energy (UHE) neutrinos is key to identifying the most energetic objects and processes in the universe. These are the sources of UHE cosmic rays, which have been detected at earth with energies exceeding 1 Joule per nucleon (roughly the kinetic energy of a bird in flight). As UHE cosmic messengers, neutrinos are unparalleled for their ability to travel from source to Earth, interacting only weakly with matter and therefore able to traverse great distances unimpeded. For this same reason, however, they are very difficult to detect (and additionally at high energies, a vanishingly small number arrive at earth). In this talk, I will discuss the general challenges in detecting UHE neutrinos, and the extensive experimental work that has been done so far to meet these challenges using various detection strategies. I'll focus on a forthcoming experimental effort, the Radar Echo Telescope (RET), which uses well-known radar technology to attempt detection of the cascade produced by these elusive neutrinos as they interact in polar ice. I'll discuss the theory and storied history of astroparticle physics, the radar echo method, recent laboratory work, and our current experimental efforts in service of UHE neutrino detection with RET.
About speaker: Steven Prohira is a physicist advancing the study of cosmic rays and ultra-high energy neutrinos through a rare combination of expertise in three distinct areas: theory, engineering, and experimental design. Prohira draws on this breadth of knowledge in his proposal for a novel method for detecting the notoriously elusive sub-atomic particles known as ultra-high energy neutrinos. Cosmic neutrinos are remnants of high energy, high temperature space events, such as nuclear fusion reactions within stars. They are electrically neutral, nearly massless, and interact very weakly with matter. Since they can pass through massive objects like planets and stars without losing energy, they are important messengers from outside of our solar system and very difficult to observe.