DUNE and Hyper-Kamiokande are the two flagship long-baseline neutrino experiments of the next decade. Both will measure leptonic CP violation and the neutrino mass ordering — among the most sought-after results in particle physics — but with complementary technologies, different baselines, and different risk profiles. They are designed in part to cross-check each other.
Side-by-side comparison
| Property | DUNE | Hyper-Kamiokande |
|---|---|---|
| Location | Fermilab → Sanford Lab (US) | J-PARC → Kamioka (Japan) |
| Baseline | 1300 km | 295 km |
| Far-detector technology | Liquid-argon TPC | Water Cherenkov |
| Fiducial mass | 40 kt (4 × 10 kt modules) | 260 kt (single tank) |
| Beam energy | Wide-band 0.5–5 GeV | Narrow-band ~0.6 GeV |
| Beam power (design) | 1.2 MW → 2.4 MW | 1.3 MW |
| First data | ~2028 (first module) | ~2027 |
| Full operation | early 2030s | late 2020s |
| Mass-ordering sensitivity | High (matter effects strong) | Modest (requires atmospheric ν or external input) |
| CP-violation 3σ reach | ~50 % of δCP values in 7 yrs | ~60 % of δCP values in 10 yrs |
| Energy resolution | ~15 % (calorimetric, charged current) | ~10 % (Cherenkov, quasi-elastic) |
| Cross-section target | Argon nucleus (40 nucleons) | Hydrogen + oxygen (water) |
| Total project cost | ~$3 billion |
The two technologies
DUNE uses liquid-argon time-projection chambers (LArTPCs). Each of its four 17-kt modules is a giant cryostat full of pure liquid argon at 87 K. When a neutrino interacts, the charged particles ionize the argon along their tracks; a uniform electric field drifts the ionization electrons sideways onto a wire-plane readout. The result is a full three-dimensional image of the event — every track, every shower, every kink — with millimetre spatial resolution.
Hyper-K uses a water Cherenkov detector, a scaled-up Super-Kamiokande. The 260-kt cylindrical tank of ultrapure water is lined with about 40,000 photomultiplier tubes. Charged secondary particles emit Cherenkov light along cones, which hit the walls as rings. The technology is mature (Super-K has run since 1996) and the fiducial volume is enormous, giving Hyper-K spectacular statistics.
The trade-off: LArTPCs offer superb event reconstruction but at high cost per kiloton; water Cherenkov is cheap per kiloton but blind to short tracks and below-threshold particles.
The two baselines
DUNE’s 1300 km baseline is deliberately long. As neutrinos travel through Earth’s mantle, the matter effect (coherent forward scattering on electrons) shifts oscillation probabilities by a few percent — and that shift differs for neutrinos versus antineutrinos, and depends on the mass ordering. At 1300 km the effect is large enough to determine the mass ordering at high significance from beam data alone.
Hyper-K’s 295 km baseline is deliberately short. The matter effect is small there, so the experiment is insensitive to mass-ordering by itself — but that also means it is less sensitive to systematic errors related to the Earth’s density profile. To break the mass-ordering degeneracy, Hyper-K plans to combine its beam data with atmospheric neutrinos observed in the same tank (which span baselines from 100s to 12,800 km through the Earth).
The two beams
DUNE uses a wide-band beam from the LBNF facility at Fermilab: neutrinos with energies from a few hundred MeV up to about 5 GeV. The breadth covers both the first oscillation maximum (at ~2.5 GeV given the 1300 km baseline) and the second oscillation maximum (at ~0.9 GeV). Measuring both maxima provides a powerful cross-check on δCP because CP violation appears with opposite signs at the two maxima.
Hyper-K uses a narrow-band off-axis beam from J-PARC: neutrinos sharply peaked near 0.6 GeV, sitting right at the 295 km first-maximum. The narrow band reduces background but means Hyper-K only measures the first oscillation maximum, relying on statistics rather than spectral information.
Where each shines
DUNE’s strengths:
- Direct mass-ordering determination from beam data alone
- Spectral information across two oscillation maxima
- Excellent event reconstruction in LArTPC — wide physics reach beyond oscillations
- Sensitivity to nucleon decay, supernova neutrinos, solar neutrinos, sterile-neutrino searches
- High-energy beam gives access to τ-neutrino appearance
Hyper-K’s strengths:
- Enormous statistics (10× Super-K, ~10⁵ atmospheric events/year)
- Ultra-low energy threshold — solar neutrinos, supernova relic, dark-matter searches
- Lower cost per kiloton, lower technical risk (mature technology)
- Better timing resolution for supernova burst direction
- Earlier first data (2027 vs 2028+)
Complementarity, not competition
The two are widely seen as complementary rather than redundant. The international neutrino community has explicitly endorsed running both:
- Cross-check on δCP: if both report consistent results, the world-average CP-phase measurement gets a factor-of-two-ish boost in precision.
- Mass ordering via different routes: DUNE from beam matter effects; Hyper-K from atmospherics; together they pin it down at >5σ.
- Cross-section systematics: DUNE measures on argon, Hyper-K on water. Joint fits can disentangle target-dependent nuclear effects that plague both.
- Different supernova sensitivity: DUNE catches the νₑ flux via charged-current interactions on argon (sensitive to the proto-neutron-star deleptonization burst); Hyper-K catches the $\bar\nu_e$ flux via inverse beta decay (sensitive to thermal cooling). The two together provide a full flavor breakdown of a galactic supernova.
The combined picture, c. 2035
Assuming nominal schedules:
- 2027: Hyper-K turns on, starts collecting atmospheric and beam neutrinos.
- 2028: DUNE’s first 10-kt LArTPC module sees first beam neutrinos.
- 2029-2030: First oscillation results from both. CP-phase precision at ~30°.
- 2032-2033: DUNE reaches design 40-kt mass and 2.4 MW beam power.
- 2034-2035: Hyper-K + DUNE combined fit gives <15° precision on δCP. Mass ordering settled at >5σ. CP violation in the lepton sector either confirmed or excluded at >5σ depending on its actual value.
If either experiment surprises us — a tension with the other, or a deviation from the three-flavor framework — the late 2030s could be the most exciting decade for neutrino physics since the discovery of oscillation itself.
The short answer
DUNE is the wide-baseline, wide-band, liquid-argon, mass-ordering-direct option in the US. Hyper-K is the short-baseline, narrow-band, water-Cherenkov, high-statistics option in Japan. Both will measure CP violation in neutrinos with complementary techniques and complementary systematic risks. Running both is widely seen as the right global strategy. By the mid-2030s, the combination should answer the two biggest open questions about ordinary neutrinos: do they violate CP, and is the mass ordering normal or inverted?
For DUNE’s underground physics, see DUNE: underground experiment for the matter mystery. For Hyper-K’s roots, see Super-Kamiokande’s 1998 oscillation discovery.
Frequently asked
What is the difference between DUNE and Hyper-Kamiokande?
DUNE is a long-baseline experiment in the US that fires a neutrino beam from Fermilab 1300 km through the Earth to a 40-kiloton liquid-argon detector at Sanford Lab in South Dakota. Hyper-Kamiokande is a Japanese experiment using a 295 km baseline from J-PARC to a 260-kiloton water Cherenkov detector in the Kamioka mine. Both target CP violation and the mass ordering, but with different technologies, different beam energies, and different systematic risk profiles.
Which will publish results first?
Hyper-Kamiokande is expected to begin data-taking in 2027 and publish its first oscillation results around 2028. DUNE's first physics module is expected to come online around 2028-2029, with the full far detector and high-power beam reaching design specification in the early 2030s. Hyper-K has a head start, but DUNE's wider energy range and second oscillation maximum may give it cleaner CP sensitivity in the long run.
Why two experiments doing the same physics?
They aren't quite doing the same thing. DUNE's 1300 km baseline crosses enough Earth matter to break the mass-ordering degeneracy outright; Hyper-K's 295 km baseline does not. Hyper-K's enormous fiducial mass gives it superb statistics on low-energy oscillation events; DUNE's wide-band beam covers both the first and second oscillation maxima. They are designed to cross-check each other and to combine in the late 2030s for the world's tightest CP-phase measurement.
What happens if they disagree?
It would be a major event in particle physics. The most likely cause would be subtle systematic differences in how each measures neutrino cross sections, which differ between argon and water targets and are still imperfectly known. A genuine tension would either point to new physics beyond the standard three-flavor framework or to under-estimated systematics in one or both. The combined fit allows the disagreement to be diagnosed.
Cite this article 5 formats
APA
Neutrino Times Editorial Team. (2026, May 21). DUNE vs Hyper-Kamiokande: the two flagship neutrino experiments of the 2030s. Neutrino Times. https://neutrino-times.com/articles/dune-vs-hyper-kamiokande-comparison/
Chicago
Neutrino Times Editorial Team. "DUNE vs Hyper-Kamiokande: the two flagship neutrino experiments of the 2030s." Neutrino Times, May 21, 2026. https://neutrino-times.com/articles/dune-vs-hyper-kamiokande-comparison/.
MLA
Neutrino Times Editorial Team. "DUNE vs Hyper-Kamiokande: the two flagship neutrino experiments of the 2030s." Neutrino Times, 21 May. 2026, https://neutrino-times.com/articles/dune-vs-hyper-kamiokande-comparison/.
BibTeX
@misc{neutrino-times-dune-vs-hyper-kamiokande-comparison,
author = {Neutrino Times Editorial Team},
title = {DUNE vs Hyper-Kamiokande: the two flagship neutrino experiments of the 2030s},
howpublished = {Neutrino Times},
year = {2026},
month = {may},
url = {https://neutrino-times.com/articles/dune-vs-hyper-kamiokande-comparison/},
note = {Accessed: 2026-05-21}
} RIS
TY - GEN TI - DUNE vs Hyper-Kamiokande: the two flagship neutrino experiments of the 2030s AU - Neutrino Times Editorial Team PY - 2026 DA - 2026-05-21 PB - Neutrino Times UR - https://neutrino-times.com/articles/dune-vs-hyper-kamiokande-comparison/ ER -