Neutrino mixing anarchy: Alive and kicking

Abstract

Neutrino mixing anarchy is the hypothesis that the leptonic mixing matrix can be described as the result of a random draw from an unbiased distribution of unitary three-by-three matrices. In light of the very strong evidence for a nonzero sin2⁡2θ13, we show that the anarchy hypothesis is consistent with the choice made by the Nature – the probability of a more unusual choice is 41%. We revisit anarchy's ability to make predictions, concentrating on correlations – or lack thereof – among the different neutrino mixing parameters, especially sin2⁡θ13 and sin2⁡θ23. We also comment on anarchical expectations regarding the magnitude of CP-violation in the lepton sector, and potential connections to underlying flavor models or the landscape.