Testing neutrino flavor mixing plus decay with neutrino telescopes

TL;DR

This paper explores how neutrino decay and oscillation phenomena affect observations at neutrino telescopes, revealing new ways to identify decay schemes and improve measurements of neutrino properties.

Contribution

It provides a comprehensive classification of neutrino decay scenarios and demonstrates their impact on neutrino telescope sensitivity and terrestrial experiments.

Findings

Unique identification of nu_1 stability scenario

Enhanced sensitivity to mass hierarchy and CP violation

Potential to establish CP violation with combined data

Abstract

We discuss the interplay of neutrino oscillation and decay properties at neutrino telescopes. Motivated by recent unparticle scenarios, which open the possibility of new neutrino decay modes over astrophysical distances, we perform a complete classification of possible decay schemes, and we illustrate how different scenarios can be identified. Moreover, we show that the sensitivity of neutrino telescopes to standard neutrino properties, such as the mass hierarchy or delta_CP, is greatly enhanced in specific decay scenarios. In particular we discuss the impact of an astrophysical neutrino detection on terrestrial experiments, such as on the mass hierarchy measurement at NOvA. For example, we find that the scenario where only nu_1 is stable can be uniquely identified against all the other decay schemes, and that in this case CP violation can be established (for large theta_13) by the combination of Double Chooz with the track-to-shower ratio at a neutrino telescope, even if the flavor composition at the source is unknown. Our statements are based on a complete analysis of all the present solar, atmospheric, reactor and accelerator neutrino data, as well as on realistic simulation of future terrestrial neutrino oscillation experiments.