Echo Technique to Distinguish Flavors of Astrophysical Neutrinos

TL;DR

This paper proposes a novel method to distinguish neutrino flavors in astrophysical observations by measuring delayed light emissions, enhancing the analysis of neutrino sources and properties.

Contribution

The paper introduces a new technique using delayed light emissions from muon decays and neutron captures to differentiate neutrino flavors, which was previously challenging.

Findings

The method can effectively distinguish $ u_e$ and $ u_ au$ in astrophysical neutrino detection.

Implementation prospects are promising for IceCube and similar detectors.

This technique improves the analysis of neutrino source characteristics.

Abstract

The flavor composition of high-energy astrophysical neutrinos is a rich observable. However, present analyses cannot effectively distinguish particle showers induced by $\nu_e$ versus $\nu_\tau$. We show that this can be accomplished by measuring the intensities of the delayed, collective light emission from muon decays and neutron captures, which are, on average, greater for $\nu_\tau$ than for $\nu_e$. This new technique would significantly improve tests of the nature of astrophysical sources and of neutrino properties. We discuss the promising prospects for implementing it in IceCube and other detectors.