A view of prompt atmospheric neutrinos with IceCube

TL;DR

This paper discusses the search for prompt atmospheric neutrinos with IceCube, which are expected to have a harder spectrum and could dominate at high energies, but have not yet been observed.

Contribution

It presents recent results from IceCube's diffuse neutrino searches, reaching sensitivity levels comparable to theoretical prompt neutrino flux predictions.

Findings

No detection of prompt atmospheric neutrinos yet

IceCube's sensitivity approaches theoretical flux levels

Prompt neutrinos could be a background in astrophysical neutrino searches

Abstract

Atmospheric neutrinos are produced in air showers, when cosmic ray primaries hit the Earth's atmosphere and interact hadronically. The conventional neutrino flux, which dominates the neutrino data measured in the GeV to TeV range by neutrino telescopes, is produced by the decay of charged pions and kaons. Prompt atmospheric neutrinos are produced by the decay of heavier mesons typically containing a charm quark. Their production is strongly suppressed, but they are expected to exhibit a harder energy spectrum. Hence, they could dominate the atmospheric neutrino flux at energies above ~ 100 TeV. Such a prompt atmospheric flux component has not yet been observed. Therefore, it is an interesting signal in a diffuse neutrino search, but also a background in the search for a diffuse astrophysical neutrino flux. The sensitivity of diffuse neutrino searches with the IceCube Neutrino observatory has reached the level of theoretical expectations of prompt neutrino fluxes, and recent results are presented.