RICE limits on the diffuse ultrahigh energy neutrino flux

Abstract

We present new limits on ultra-high energy neutrino fluxes above 10 17 eV based on data collected by the Radio Ice Cherenkov Experiment (RICE) at the South Pole from 1999-2005. We discuss estimation of backgrounds, calibration and data analysis algorithms (both on-line and off-line), procedures used for the dedicated neutrino search, and refinements in our Monte Carlo (MC) simulation, including recent in situ measurements of the complex ice dielectric constant. An enlarged data set and a more detailed study of hadronic showers results in a sensitivity improvement of more than one order of magnitude compared to our previously published results. Examination of the full RICE data set yields zero acceptable neutrino candidates, resulting in 95% confidence-level model dependent limits on the flux E 2 ν dφ/dE ν < 10 −6 GeV/(cm 2 s sr) in the energy range 10 17 < E ν < 10 20 eV. The new RICE results rule out the most intense flux model projections at 95% confidence level.

Measurement of sound speed vs. depth in South Pole ice for neutrino astronomy

“…The AMANDA [2] and IceCube [3] detectors have been developed to exploit this for optical neutrino detection. Antarctic ice is even more transparent in radio wavelengths [4], [5], and the Radio Ice Cherenkov Experiment (RICE) [6] was operated to search for radio signals from astrophysical neutrinos. In situ measurements of the acoustic attenuation length in South Pole ice are underway [7].…”

Radio detection of ultra-high energy cosmic neutrinos

“…This sensitivity projection is representative of the projections for a variety of the next-generation experiments, since this is approximately the sensitivity level required to detect UHE neutrinos, even in the most pessimistic flux models. The limits are from ANITA-II [4], IceCube [5], Auger [6], and RICE [7]. The model curves are from a variety of models, including those with optimistic and pessimistic assumptions [8,9,10,11,12].…”

“…Current experimental efforts monitor enormous volumes of glacial ice, whose radio attenuation properties have been directly measured at multiple locations in Antarc- , and RICE [7]. The model curves are from a variety of models, including those with optimistic and pessimistic assumptions [8,9,10,11,12].…”

Neutrino Astrophysics with the ANTARES Telescope

“…(3) ANITA upper limit (Gorham et al 2012). (4) RICE upper limit (Kravchenko et al 2006). (5) the Askaryan Radio Array (ARA) estimated 3-year sensitivity (Allison et al 2012).…”