Neutrino Mass and Oscillation

TL;DR

This paper reviews the evidence for neutrino masses and oscillations, discussing their implications for particle physics and cosmology, and explores future experimental prospects to better understand neutrino properties.

Contribution

It provides a comprehensive review of neutrino oscillation physics, evidence, and constraints, along with proposed future experiments to elucidate neutrino masses.

Findings

Strong evidence for neutrino oscillation in nature

Neutrino masses could significantly impact cosmic mass density

Future experiments can clarify neutrino mass spectra

Abstract

The question of neutrino mass is one of the major riddles in particle physics. Recently, strong evidence that neutrinos have nonzero masses has been found. While tiny, these masses could be large enough to contribute significantly to the mass density of the universe. The evidence for nonvanishing neutrino masses is based on the apparent observation of neutrino oscillation -- the transformation of a neutrino of one type or "flavor" into one of another. We explain the physics of neutrino oscillation, and review and weigh the evidence that it actually occurs in nature. We also discuss the constraints on neutrino mass from cosmology and from experiments with negative results. After presenting illustrative neutrino mass spectra suggested by the present data, we consider how near- and far-future experiments can further illuminate the nature of neutrinos and their masses.