New MACRO results on atmospheric neutrino oscillations

TL;DR

The MACRO experiment's final results on atmospheric neutrino oscillations support nu_mu to nu_tau oscillations with maximal mixing and a specific mass-squared difference, using various event analyses and energy estimation techniques.

Contribution

This paper provides the final analysis of MACRO data on atmospheric neutrino oscillations, confirming oscillation parameters with multiple event topologies and energy estimation methods.

Findings

Supports nu_mu --> nu_tau oscillations with maximal mixing

Determines Delta m^2 = 0.0023 eV^2

Uses multiple Coulomb Scattering for energy estimation

Abstract

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.