Spectrum of PeV Cosmic-Ray Protons and Helium Nuclei with IceCube

TL;DR

This paper presents a new method to reconstruct the combined spectrum of cosmic-ray protons and helium nuclei starting at 200 TeV, filling a gap in measurements between existing experiments and extending the energy range of composition analysis.

Contribution

The study introduces a novel reconstruction method for the H+He spectrum from IceCube data, extending the energy range down to 200 TeV and bridging previous measurement gaps.

Findings

Reconstructed the H+He spectrum starting at 200 TeV.

Extended cosmic-ray composition analysis to lower energies.

Bridged measurement gaps between IceCube, KASCADE, DAMPE, and HAWC.

Abstract

The IceCube Observatory comprises a cubic-kilometer particle detector deep in the Antarctic ice and the cosmic-ray air-shower array IceTop at the surface above. Previous analyses of the cosmic-ray composition have used coincident events with IceTop detecting the electromagnetic shower footprint as well as GeV muons, while the sensors submerged in the ice measure the TeV muons from the same events. The energy range of previous composition analyses, however, has been limited to 3 PeV primary energy and above, whereas the IceTop all-particle energy spectrum has been extended down to 250 TeV. This contribution presents a method to reconstruct the combined spectrum of cosmic-ray protons and helium nuclei, starting at 200 TeV primary energy. The resulting H+He spectrum closes the gap in the measurements of light cosmic rays between IceCube as well as KASCADE and experiments measuring in the TeV energy range, such as DAMPE and HAWC.