Neutrino Mass Anarchy

TL;DR

It is demonstrated that the data are well accounted for by a neutrino mass matrix which appears to have random entries.

Abstract

What is the form of the neutrino mass matrix which governs the oscillations of the atmospheric and solar neutrinos? Features of the data have led to a dominant viewpoint where the mass matrix has an ordered, regulated pattern, perhaps dictated by a flavor symmetry. We challenge this viewpoint, and demonstrate that the data are well accounted for by a neutrino mass matrix which appears to have random entries.

Figures (3)

• Figure 1: The distribution of $\Delta m^2_{\odot} / \Delta m^2_{atm}$ for Dirac (solid) Majorana (dot-dashed) and seesaw (dashed) scenarios.
• Figure 2: Plots of the normalized, binned distributions of $s_{atm}$ for Dirac, Majorana and seesaw cases. Contrary to intuition, the distributions actually peak at large $s_{atm}$.
• Figure 3: Plots of the normalized, binned distributions of $s_{\odot}$ for Dirac (a), Majorana (b), and seesaw (c) cases. The distribution after imposing the $s_C$ cut (solid) shows a greater preference for large $s_{\odot}$ compared with the original distribution (dashed).