First Constraints on the Ultra-High Energy Neutrino Flux from a   Prototype Station of the Askaryan Radio Array
  The Askaryan Radio Array (ARA) is an ultra-high energy ($>10^{17}$ eV) cosmic neutrino detector in phased construction near the South Pole. ARA searches for radio Cherenkov emission from particle cascades induced by neutrino interactions in the ice using radio frequency antennas ($\sim150-800$ MHz) deployed at a design depth of 200 m in the Antarctic ice. A prototype ARA Testbed station was deployed at $\sim30$ m depth in the 2010-2011 season and the first three full ARA stations were deployed in the 2011-2012 and 2012-2013 seasons. We present the first neutrino search with ARA using data taken in 2011 and 2012 with the ARA Testbed and the resulting constraints on the neutrino flux from $10^{17}-10^{21}$ eV. 
ARA Collaboration: P. Allison, J. Auffenberg, R. Bard, J. J. Beatty,   D. Z. Besson, C. Bora, C.-C. Chen, P. Chen, A. Connol...
astro-ph.HE astro-ph.IM