Discovering the Highest Energy Astrophysical Neutrinos Using a Radio Phased Array

Ultra-high energy neutrino astronomy sits at the boundary between particle physics and astrophysics. The detection of high energy neutrinos is an important step toward understanding the most energetic cosmic accelerators and would enable tests of fundamental physics at energy scales that cannot easily be achieved on Earth. IceCube has detected astrophysical neutrinos at lower energies, but the best limit to date on the flux of ultra-high energy neutrinos comes from the ANITA experiment, a NASA balloon-borne radio telescope designed to detect coherent radio Cherenkov emission from cosmogenic ultra-high energy neutrinos. The future of high energy neutrino detection lies with ground-based radio arrays, which would represent a large leap in sensitivity. I will discuss the demonstrated performance of a new radio phased array design that we have implemented on the ARA experiment at the South Pole and on the new BEACON experiment on White Mountain in California. The radio phased array has improved sensitivity to high energy cosmic particles and will push the energy threshold for radio detection down to overlap with the energy range probed by IceCube.