Approximating new ice models with B-splines for improved IceCube event reconstruction: application to cascades and tracks

TL;DR

This paper introduces enhanced ice modeling using B-splines in IceCube, significantly improving event reconstruction accuracy for cascades and tracks, especially in angular resolution and directional likelihood estimation.

Contribution

It presents a novel application of B-spline based ice models to improve the accuracy of IceCube event reconstruction for cascades and tracks.

Findings

Median angular resolution for showers improved by a factor of two.

Enhanced ice modeling yields more accurate directional contours for tracks.

Calibration improvements lead to better angular resolution of electromagnetic showers.

Abstract

Event signatures in IceCube are complex, modulated by both particle physics and properties of the ice and detector. Event reconstruction thus requires accurate modeling of ice properties and detector effects to fit for physics parameters, such as energy and direction. Here, we highlight how improvements in calibration can translate into substantially improving the angular resolution of electromagnetic showers. Since showers are also used to model stochastic energy losses of tracks, we further show how improved ice modeling, along with other track-specific optimizations, leads to more meaningful directional likelihood spaces for high-energy muons. The median angular resolution for showers is improved by a factor of two over an older B-spline model, and accurate directional contours for tracks can be obtained with Wilks' theorem.