Data Combinations For Neutrion Oscillations

The PMNS matrix with non-zero CP conservation and a normal ordering of neutrino masses is still a good description of all of the available raw data from four leading neutrino experiments (without the need for right handed or otherwise sterile neutrinos, or non-standard neutrino interactions, or Majorana neutrino mass). 

This is hardly breaking news but provides yet another confirmation, independent of the major neutrino physics collaborations that this fairly simple model of neutrino physics works.

We present the first combined oscillation analysis of multiple atmospheric neutrino datasets, featuring data from Super-Kamiokande, IceCube-DeepCore, and KM3NeT/ORCA together with reactor data from Daya Bay. 

Such combinations have long been considered infeasible outside experimental collaborations; we demonstrate that a unified physics model can simultaneously describe all datasets with no significant parameter tensions. 

Fitting 839,048 events across 1536 bins with 91 parameters, our combined analysis yields competitive measurements of the neutrino mixing parameters, disfavors CP conservation, and prefers the Normal over the Inverted Mass Ordering.

Philipp Eller, "Atmospheric Neutrino Oscillations: the Full Picture" arXiv:2606.09714 (June 8, 2026).

The body text notes that:

We disfavor the absence of CP violation at ∆χ2 = 8.06 and the Inverted Ordering at ∆χ2 = 9.11.

These preferences are statistically significant at a more than 95% confidence level.

The preference for normal ordering is about three sigma (roughly a 99% confidence level). 

This preference is also corroborated by an independent statistically significant preference for a normal ordering from cosmology data that strengthens that preference when cosmology data is combined with terrestrial experimental data. But quantifying the cosmology data preference is challenging because it is cosmology model dependent (see also here). 

Cosmology data does, however, consistently favor a lightest neutrino mass eigenstate far less massive than the Katrin direct neutrino mass measurement experiments (by two or three orders of magnitude).

Neutrinoless beta decay experiments (which imply Majorana neutrino mass limits) aren't yet powerful enough to make meaningful statements about neutrino masses relative to other data sources for neutrino masses.

A Preon Model

There are lots of issues with preon models that model at least some of the Standard Model fundamental particles as composite (experimental limits on compositeness are strict and naively rule them out for simpler models). But this is a more interesting one than most.

We build a framework for Regge trajectories from the Nambu-Goto action. We compute the 6-preon Regge trajectory in a preon model, include the worldsheet conformal anomaly, and build the parameter-free Veneziano amplitude. The amplitude has s-channel poles matching the spectrum to 0.5%, and at fixed-angle scattering decays exponentially with a negative Gross-Mende coefficient, realized numerically to 0.03%. 

This is a soft, genuinely non-perturbative ultraviolet completion of the preon model - and thereby of the Standard Model, which emerges as its low-energy limit.

Risto Raitio, "Soft UV Completion of a Preon Model" arXiv:2606.06541 (June 4, 2026).

The model used in this case is spelled out in the introduction:

Quarks and leptons arise as three-preon composites bound at the metacolor scale Λ(cr); the three fermion generations emerge not as a postulated multiplicity but as dynamical excitations of these composites; and the chiral, anomaly-free matter content of one Standard Model family is reproduced from a small set of preon charges. In this picture the Standard Model is the low-energy limit of a confining metacolor gauge theory, much as hadronic physics is the low-energy limit of QCD.