Study of the acoustic signature of UHE neutrino interactions in water and ice

The production of acoustic signals from the interactions of ultra-high energy (UHE) cosmic ray neutrinos in water and ice has been studied. A new computationally fast and efficient method of deriving the signal is presented. This method allows the implementation of up to date parameterisations of acoustic attenuation in sea water and ice that now includes the effects of complex attenuation, where appropriate. The methods presented here have been used to compute and study the properties of the acoustic signals which would be expected from such interactions. A matrix method of parameterising the signals, which includes the expected fluctuations, is also presented. These methods are used to generate the expected signals that would be detected in acoustic UHE neutrino telescopes.Comment: 21 pages and 13 figure

Underwater Acoustic Detection of Ultra High Energy Neutrinos

We investigate the acoustic detection method of 10^18-20 eV neutrinos in a Mediterranean Sea environment. The acoustic signal is re-evaluated according to dedicated cascade simulations and a complex phase dependant absorption model, and compared to previous studies. We detail the evolution of the acoustic signal as function of the primary shower characteristics and of the acoustic propagation range. The effective volume of detection for a single hydrophone is given taking into account the limitations due to sea bed and surface boundaries as well as refraction effects. For this 'benchmark detector' we present sensitivity limits to astrophysical neutrino fluxes, from which sensitivity bounds for a larger acoustic detector can be derived. Results suggest that with a limited instrumentation the acoustic method would be more efficient at extreme energies, above 10^20 eV.Comment: 15 pages, 11 figure