Atmospheric neutrino oscillations with MACRO

TL;DR

This paper reports on atmospheric neutrino oscillation studies using the MACRO detector, providing evidence for nu_mu to nu_tau oscillations with maximal mixing and a specific mass-squared difference, through analysis of different energy samples and oscillation hypotheses.

Contribution

It offers new experimental results supporting nu_mu to nu_tau oscillations, including energy estimation and sterile neutrino hypothesis testing with the MACRO detector.

Findings

Strong evidence for nu_mu to nu_tau oscillations

Maximal mixing with Delta_m^2 = 2.5 x 10^-3 eV^2

Consistent results across energy samples and hypotheses

Abstract

We present the latest results on the study of atmospheric neutrino oscillations with the MACRO detector at Gran Sasso. Two sub-samples of events have been analysed, both in terms of absolute flux and zenith angle distribution: high energy events (with <E>~50 GeV) and low energy events (with <E>~4 GeV). The high energy sample has been used also to check the nu_mu <-> nu_sterile oscillation hypothesis and to estimate neutrino energies using Multiple Coulomb Scattering informations. All these analyses are mutually consistent and strongly favour the nu_mu <-> nu_tau oscillation hypothesis with maximal mixing and Delta_m^2 = 2.5 10^-3 eV^2.