Matter effects on flavor transitions of high-energy astrophysical neutrinos based on typical propagation schemes

TL;DR

This paper investigates how matter effects influence the flavor composition of high-energy astrophysical neutrinos during propagation, highlighting the dependence on environmental density and propagation schemes, which can be tested by future neutrino observations.

Contribution

It provides a detailed analysis of matter effects on neutrino flavor transitions under different propagation schemes and environmental densities, offering predictions for future observational constraints.

Findings

Matter effects are significant at certain densities in adiabatic schemes.

Constant density environments show negligible matter effects even at high densities.

Next-generation detectors can test propagation models based on flavor composition measurements.

Abstract

Precise measurements of the flavor ratio of high energy astronomical neutrinos (HANs) would be promising in the following decades. Then matter effects and new physics effects on the flavor transition of HANs could be tested. In this paper, we examine matter effects on the flavor composition of HANs. The effects are dependent on propagation schemes and sources of neutrinos. We consider propagations in environments with adiabatically varying and constant electron density. In the adiabatic case, the matter influence on the flavor composition of HANs at Earth is noticeable at the electron density 10$^{10}$ cm$^{-3}$ in the cases of muon damping and neutron decaying sources. In contrast, in the constant density case, the matter effect can be neglected even at the density 10$^{18}$ cm$^{-3}$. Thus, observations from next-generation neutrino telescopes may set stringent constraints on the adiabatic propagation scheme.