The fate of hints: updated global analysis of three-flavor neutrino oscillations

Abstract

Our herein described combined analysis of the latest neutrino oscillation data presented at the Neutrino2020 conference shows that previous hints for the neutrino mass ordering have significantly decreased, and normal ordering (NO) is favored only at the 1.6 σ level. Combined with the χ2 map provided by Super-Kamiokande for their atmospheric neutrino data analysis the hint for NO is at 2.7 σ. The CP conserving value δCP = 180° is within 0.6 σ of the global best fit point. Only if we restrict to inverted mass ordering, CP violation is favored at the ∼ 3 σ level. We discuss the origin of these results — which are driven by the new data from the T2K and NOvA long-baseline experiments —, and the relevance of the LBL-reactor oscillation frequency complementarity. The previous 2.2 σ tension in ∆m221 preferred by KamLAND and solar experiments is also reduced to the 1.1 σ level after the inclusion of the latest Super-Kamiokande solar neutrino results. Finally we present updated allowed ranges for the oscillation parameters and for the leptonic Jarlskog determinant from the global analysis.