Searches for Large-Scale Anisotropies of Cosmic Rays: Harmonic Analysis and Shuffling Technique

TL;DR

This paper introduces a shuffling technique for measuring large-scale cosmic ray anisotropies, enabling accurate harmonic analysis of arrival directions without complex corrections for detector effects.

Contribution

It presents a novel shuffling method that simplifies anisotropy measurements in cosmic ray data, applicable to any detector without extra corrections.

Findings

Effective in reducing experimental biases

Applicable across different cosmic ray detectors

Enhances sensitivity to small anisotropies

Abstract

The measurement of large scale anisotropies in cosmic ray arrival directions is generally performed through harmonic analyses of the right ascension distribution as a function of energy. These measurements are challenging due to the small expected anisotropies and meanwhile the relatively large modulations of observed counting rates due to experimental effects. In this paper, we present a procedure based on the shuffling technique to carry out these measurements, applicable to any cosmic ray detector without any additional corrections for the observed counting rates.