Evidence for an oscillatory signature in atmospheric neutrino oscillation

TL;DR

This paper presents evidence of an oscillatory pattern in atmospheric muon neutrino disappearance, confirming the sinusoidal nature of neutrino flavor transitions and constraining key oscillation parameters.

Contribution

It provides experimental evidence for the oscillatory signature in atmospheric neutrinos and refines the measurement of neutrino oscillation parameters.

Findings

Observed a dip in the L/E distribution consistent with oscillations.

Constrained neutrino oscillation parameters: Delta m^2 between 1.9x10^-3 and 3.0x10^-3 eV^2.

Established a lower bound on sin^2(2theta) as 0.90 at 90% confidence.

Abstract

Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu_mu <-> nu_tau neutrino oscillation parameters; 1.9x10^-3 < Delta m^2 < 3.0x10^-3 eV^2 and \sin^2(2theta) > 0.90 at 90% confidence level.