Neutrino masses and oscillations: triumphs and challenges

Abstract

The recent progress in establishing the existence of finite neutrino masses and mixing between generations of neutrinos has been remarkable, if not astounding. The combined results from studies of atmospheric neutrinos, solar neutrinos, and reactor antineutrinos paint an intriguing picture for theorists and provide clear motivation for future experimental studies. In this review, we summarize the status of experimental and theoretical work in this field and explore the future opportunities that emerge in light of recent discoveries.

How much uranium is in the Earth? Predictions for geoneutrinos at KamLAND

“…Statistical fluctuations imply an error of, at least, 5.7 counts. Indeed, this first indication of geo-neutrinos stimulated several investigations [13,14,15,16,17,18,19,20].…”

Description of double β decay within the continuum quasiparticle random-phase approximation

“…[1]). However, the absolute scale of the neutrino masses cannot in principle be deduced from the observed oscillations.…”

Measuring Neutrino Oscillations with Nuclear Reactors

“…During the last decade, we have obtained evidence for much stronger mixing of the neutrino flavor states [2]. This requires that neutrinos have finite mass, and implies that the mechanism for generating misalignment of the mass and flavor eigenstates is of greater importance than for the quarks.…”

“…The CKM matrix is almost diagonal, and so it seems that there is some minor lack of alignment of the flavor and mass eigenstates. This slight rotation generates many interesting phenomena, including CP violation, but its origin is not understood at a fundamental level.During the last decade, we have obtained evidence for much stronger mixing of the neutrino flavor states [2]. This requires that neutrinos have finite mass, and implies that the mechanism for generating misalignment of the mass and flavor eigenstates is of greater importance than for the quarks.…”