Neutrino Propagation in Matter

TL;DR

This paper reviews how neutrinos change as they pass through Earth's matter, focusing on phenomena like resonance and adiabatic conversion, and discusses how these effects can help determine neutrino properties using current and future experiments.

Contribution

It provides a comprehensive semi-analytic framework for understanding neutrino flavor transitions in Earth's matter and explores experimental strategies for identifying neutrino mass hierarchy.

Findings

Resonance enhancement of oscillations in constant density

Adiabatic conversion in slowly changing density

Potential to determine neutrino mass hierarchy with atmospheric and accelerator neutrinos

Abstract

We describe the effects of neutrino propagation in the matter of the Earth relevant for experiments with atmospheric and accelerator neutrinos and aimed at the determination of the neutrino mass hierarchy and CP-violation. These include (i) the resonance enhancement of neutrino oscillations in matter with constant or nearly constant density, (ii) adiabatic conversion in matter with slowly changing density, (iii) parametric enhancement of oscillations in a multi-layer medium, (iv) oscillations in thin layers of matter. We present the results of semi-analytic descriptions of flavor transitions for the cases of small density perturbations, in the limit of large densities and for small density widths. Neutrino oscillograms of the Earth and their structure after determination of the 1-3 mixing are described. A possibility to identify the neutrino mass hierarchy with the atmospheric neutrinos and multi-megaton scale detectors having low energy thresholds is explored. The potential of future accelerator experiments to establish the hierarchy is outlined.