Concept study for the beamforming elevated array for cosmic neutrinos (BEACON)

Tau neutrinos are expected to comprise one third of both the astrophysical and cosmogenic neutrino flux, but currently the flavor ratio is poorly constrained and the expected flux at energies >100 PeV is low. We present a new concept for a radio detector called BEACON sensitive to tau neutrinos with energies greater than 100 PeV in which a radio interferometer searches for upgoing tau neutrinos from a high elevation mountain. Signals from several antennas are coherently summed at the trigger level, permitting not only directional masking of anthropogenic backgrounds, but also a lower trigger threshold. Simulation studies indicate that a modest array size and small number of stations can achieve competitive sensitivity, provided the receivers are at high enough elevation. As a proof of concept, an array of four 30-80 MHz dual polarized antennas was deployed at the White Mountain Research Station. Acknowledgements We gratefully acknowledge funding from the NSF CAREER Award #1752922, the NSF Award #DGE-1746045, the Cal Poly Frost Fund, the Ministerio de Economía, Industria y Competitividad (FPA2017-85114-P and María de Maeztu Unit of Excellence MDM-2016-0692) and the Xunta de Galicia (ED431C 2017/07) as well as the outstanding staff at WMRS and OVRO and computing resources provided by the Univ. of Chicago Research Computing Center.