Methods for point source analysis in high energy neutrino telescopes

TL;DR

This paper presents advanced analysis methods for detecting astrophysical neutrino sources with deep ice or sea detectors, emphasizing unbinned likelihood techniques that improve sensitivity over traditional binned searches.

Contribution

It introduces an unbinned likelihood ratio method utilizing point spread function and energy data, enhancing detection capabilities for high energy neutrino sources.

Findings

Unbinned likelihood methods outperform binned searches.

Energy information can nearly double discovery potential.

Simulations based on real detector performance validate the approach.

Abstract

Neutrino telescopes are moving steadily toward the goal of detecting astrophysical neutrinos from the most powerful galactic and extragalactic sources. Here we describe analysis methods to search for high energy point-like neutrino sources using detectors deep in the ice or sea. We simulate an ideal cubic kilometer detector based on real world performance of existing detectors such as AMANDA, IceCube, and ANTARES. An unbinned likelihood ratio method is applied, making use of the point spread function and energy distribution of simulated neutrino signal events to separate them from the background of atmospheric neutrinos produced by cosmic ray showers. The unbinned point source analyses are shown to perform better than binned searches and, depending on the source spectral index, the use of energy information is shown to improve discovery potential by almost a factor of two.