Neutrino news
Experiments, results and recently published work from across the field.
In summary. This week's news is dominated by hardware progress and source searches rather than new oscillation results: DUNE's cryostat steel installation and KM3NeT's ARCA62 sea campaign both advanced, while IceCube continued hunting for the origin of KM3NeT's record-breaking 220 PeV neutrino candidate and other astrophysical sources. On the theory side, a combined atmospheric-neutrino analysis spanning four experiments reported a 3-sigma preference for the normal mass ordering, alongside new global limits on the Majorana neutrino mass from ab initio nuclear theory. This paragraph summarises the items below; the sources are on the items themselves.
Crews at the Sanford Underground Research Facility have installed about 39% of the I-beam steel needed for the DUNE cryostat, close to 2 million pounds now filling the 500-foot-long south cavern. The milestone was reported alongside a DUNE Collaboration Meeting held at Unicamp to review progress on the project.
A sea campaign at the KM3NeT ARCA site enlarged the submarine infrastructure and added detector elements, described by the collaboration as a significant step forward in construction.
IceCube has searched for the source of the highest-energy neutrino candidate ever recorded, the 220 PeV event reported by the KM3NeT ARCA telescope.
During the 2025/26 austral summer, five new strings carrying new photosensor designs were deployed as a dense infill in the existing IceCube array. The collaboration has also reported projected sensitivities for the IceCube Upgrade, building on evidence that active galaxies are sources of high-energy neutrinos.
IceCube has reported a new search for steady-state neutrino emission with DeepCore, following its earlier evidence for high-energy neutrinos from the active galaxy NGC 1068, and a separate search for neutrino emission from tidal disruption events, extending its hunt for the origins of the astrophysical neutrino flux.
IceCube data have also been used to search for signatures of extra dimensions, motivated by the unresolved hierarchy problem between the weak force and gravity.
Two papers report progress on T2K's upgraded ND280 near detector: a deep-learning particle-identification method for the new SuperFGD sub-detector, and a new event selection for muon-neutrino charged-current interactions with single pion production using the ND280 modules completed in 2024. Both aim to reduce the systematic uncertainties that dominate T2K's oscillation analysis.
Baikal-GVD, a cubic-kilometre-scale detector under construction in Lake Baikal and now 70% complete, has searched for point-like astrophysical neutrino sources using a five-year track-like dataset from 2019-2024. No significant source was found, and the resulting upper limits were compared with published IceCube, ANTARES and KM3NeT results.
The SHiP/NA67 collaboration has described the detector subsystems for its planned experiment at the CERN SPS, which will search for feebly interacting GeV-scale particles and carry out all-flavour neutrino measurements at the HI-ECN3 beam facility. Commissioning and first physics runs are planned for 2032-2033.
A new analysis applies simulation-based inference to jointly fit MiniBooNE and MicroBooNE data within a 3+1 sterile-neutrino framework, using MicroBooNE data from both the Booster Neutrino Beam and NuMI beamlines. The study evaluates the statistical tension between the MiniBooNE low-energy excess and its exclusion by MicroBooNE.
recently published, with the links each record carries
This paper presents the first combined oscillation analysis using recent atmospheric neutrino data from Super-Kamiokande, IceCube-DeepCore and KM3NeT/ORCA together with reactor data from Daya Bay, fitting 839,048 events across 1536 bins with 91 parameters. The unified model describes all four datasets with no significant tensions and prefers the normal over the inverted mass ordering at 3-sigma, a cross-collaboration combination long considered infeasible outside the experiments themselves.
Atmospheric neutrino oscillations: The full picture — arXiv · INSPIRE · DOIThe authors derive global limits on the Majorana neutrino mass by combining likelihoods from multiple neutrinoless double-beta decay experiments with nuclear matrix elements computed ab initio from chiral effective field theory. In contrast to phenomenological nuclear models, their ab initio results indicate that the current generation of 0-nu-beta-beta experiments has likely not yet reached the sensitivity needed to probe the relevant mass range.
Global ab initio neutrino mass limits from neutrinoless double-beta decay — arXiv · INSPIRE · DOIThis paper introduces TAMBO, a mountain-based neutrino observatory designed to help map the high-energy neutrino sky, a goal that has remained elusive despite a decade of progress in neutrino astronomy. The authors present it as a route to filling gaps in the observed sky while also searching for new physics.
Measuring the high-energy neutrino sky using the deep-valley neutrino observatory TAMBO — INSPIRE · DOIThis review summarises the properties of KM3-230213A, the ultra-high-energy neutrino event detected by KM3NeT with an inferred parent-neutrino energy of order 10^17 eV, and surveys its possible astrophysical and cosmological interpretations. Despite extensive follow-up, no unambiguous electromagnetic counterpart has been identified, leaving the event's origin open.
KM3-230213A: The Highest-Energy Cosmic Neutrino — INSPIRE · DOIThis paper proposes a minimal extension of the Standard Model in which a single U(1)PQ symmetry simultaneously sets the inverse-seesaw scales for neutrino mass and stabilises a fermionic dark matter candidate, with an associated axion-like particle mediating between the two sectors. The model generates neutrino masses at the TeV scale and predicts a correlation between the effective Majorana mass and a CP-violating phase, giving it testable consequences for double-beta decay searches.
Fermionic dark matter and neutrino masses in a minimal U(1)PQ inverse seesaw framework — INSPIRE · DOIThe authors study composite neutrino models in which heavy neutrinos arise as bound states of a near-conformal strongly coupled sector, mixing with Standard Model neutrinos via an inverse seesaw. The setup predicts electromagnetic transition dipole couplings parametrically larger than those of minimal Dirac or Majorana models, with simulated production-and-decay signatures relevant to future searches.
Neutrino dipole moments and radiative signatures from partial compositeness — arXiv · INSPIRE · DOI