First search for extraterrestrial neutrino-induced cascades with IceCube

TL;DR

This paper presents the first search for extraterrestrial neutrino-induced cascades using IceCube data from 2007, detailing analysis methods, background suppression, and flux limits in the energy range from 20 TeV to a few PeV.

Contribution

It introduces the first search for neutrino-induced cascades in IceCube, including analysis techniques and background rejection methods for the 2007 dataset.

Findings

No significant neutrino signal detected.

Established limits on diffuse extraterrestrial neutrino flux.

Demonstrated cascade reconstruction capabilities in IceCube.

Abstract

We report on the first search for extra-terrestrial neutrino-induced cascades in IceCube. The analyzed data were collected in the year 2007 when 22 detector strings were installed and operated. We will discuss the analysis methods used to reconstruct cascades and to suppress backgrounds. Simulated neutrino signal events with a E-2 energy spectrum, which pass the background rejection criteria, are reconstructed with a resolution dlogE ~ 0.27 in the energy range from ~20 TeV to a few PeV. We present the range of the diffuse flux of extra-terrestrial neutrinos in the cascade channel in IceCube within which we expect to be able to put a limit.