K2K experiment
E861502
The K2K experiment was a long-baseline neutrino experiment in Japan that sent a beam of muon neutrinos from KEK to the Super-Kamiokande detector, providing early accelerator-based evidence for neutrino oscillations.
All labels observed (1)
| Label | Occurrences |
|---|---|
| K2K experiment canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T10376303 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: K2K experiment Context triple: [neutrino oscillation, confirmedBy, K2K experiment]
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A.
Kamiokande experiment
The Kamiokande experiment was a pioneering Japanese neutrino observatory that provided key evidence for solar and atmospheric neutrinos, contributing to the discovery of neutrino oscillations.
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B.
KamLAND experiment
The KamLAND experiment is a neutrino observatory in Japan that made landmark measurements of neutrino oscillations by detecting antineutrinos from distant nuclear reactors and the Earth’s interior.
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C.
T2K
T2K is a long-baseline neutrino oscillation experiment in Japan that studies how neutrinos change type as they travel from J-PARC to the Super-Kamiokande detector.
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D.
Super-Kamiokande Collaboration
The Super-Kamiokande Collaboration is an international team of physicists operating the Super-Kamiokande neutrino observatory in Japan, renowned for its groundbreaking discoveries in neutrino oscillations and particle physics.
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E.
MINOS experiment
The MINOS experiment is a long-baseline neutrino oscillation project that studied how neutrinos change type as they travel from Fermilab to a distant underground detector.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: K2K experiment Target entity description: The K2K experiment was a long-baseline neutrino experiment in Japan that sent a beam of muon neutrinos from KEK to the Super-Kamiokande detector, providing early accelerator-based evidence for neutrino oscillations.
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A.
Kamiokande experiment
The Kamiokande experiment was a pioneering Japanese neutrino observatory that provided key evidence for solar and atmospheric neutrinos, contributing to the discovery of neutrino oscillations.
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B.
KamLAND experiment
The KamLAND experiment is a neutrino observatory in Japan that made landmark measurements of neutrino oscillations by detecting antineutrinos from distant nuclear reactors and the Earth’s interior.
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C.
T2K
T2K is a long-baseline neutrino oscillation experiment in Japan that studies how neutrinos change type as they travel from J-PARC to the Super-Kamiokande detector.
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D.
Super-Kamiokande Collaboration
The Super-Kamiokande Collaboration is an international team of physicists operating the Super-Kamiokande neutrino observatory in Japan, renowned for its groundbreaking discoveries in neutrino oscillations and particle physics.
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E.
MINOS experiment
The MINOS experiment is a long-baseline neutrino oscillation project that studied how neutrinos change type as they travel from Fermilab to a distant underground detector.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
long-baseline neutrino experiment
ⓘ
particle physics experiment ⓘ |
| baselineLength | approximately 250 km ⓘ |
| baselineType | long-baseline ⓘ |
| beamEnergyRange | sub-GeV to few-GeV neutrinos ⓘ |
| beamSourceLocation | KEK NERFINISHED ⓘ |
| beamTargetLocation | Super-Kamiokande NERFINISHED ⓘ |
| collaborationType | international collaboration ⓘ |
| confirmedObservationOf | atmospheric neutrino oscillation seen by Super-Kamiokande ⓘ |
| country | Japan ⓘ |
| countryOfFarDetector | Japan NERFINISHED ⓘ |
| countryOfNearDetector | Japan NERFINISHED ⓘ |
| dataTakingPeriod | 1999–2004 ⓘ |
| detectionMedium | water Cherenkov detector ⓘ |
| distanceFromKEKToSuperKamiokande | about 250 km GENERATED ⓘ |
| endYear | 2004 ⓘ |
| evidenceType | accelerator-based evidence for neutrino oscillations ⓘ |
| farDetector | Super-Kamiokande NERFINISHED ⓘ |
| field |
high-energy physics
ⓘ
neutrino physics ⓘ |
| hostInstitution | KEK NERFINISHED ⓘ |
| locatedIn | Japan ⓘ |
| measuredQuantity |
mass-squared difference of atmospheric neutrino oscillation
ⓘ
mixing angle for atmospheric neutrino oscillation ⓘ |
| nearDetector | KEK near detector complex NERFINISHED ⓘ |
| neutrinoBeamDirection | from KEK to Super-Kamiokande ⓘ |
| neutrinoFlavorAtDetection | muon neutrino disappearance ⓘ |
| neutrinoFlavorAtSource | muon neutrino ⓘ |
| neutrinoProductionMethod | decay of secondary mesons produced by protons on target ⓘ |
| oscillationChannelStudied | muon neutrino to tau neutrino ⓘ |
| parentMesonType |
kaon
ⓘ
pion ⓘ |
| pioneeringStatus | first long-baseline accelerator neutrino experiment to confirm atmospheric neutrino oscillation ⓘ |
| primaryProtonEnergy | 12 GeV GENERATED ⓘ |
| producedNeutrinoBeamType | muon neutrino beam ⓘ |
| providedEvidenceFor | neutrino oscillation ⓘ |
| publicationType | results published in peer-reviewed journals ⓘ |
| resultType |
measurement of neutrino oscillation parameters
ⓘ
observation of muon neutrino disappearance ⓘ |
| startYear | 1999 ⓘ |
| status | completed ⓘ |
| studiedPhenomenon | neutrino oscillation ⓘ |
| successorExperiment | T2K experiment NERFINISHED ⓘ |
| usedBeamType | conventional horn-focused neutrino beam ⓘ |
| usedDetectorTechnology |
scintillator and tracking detectors at near site
ⓘ
water Cherenkov detection at far site ⓘ |
| usesAccelerator | KEK proton synchrotron NERFINISHED ⓘ |
| usesDetector | Super-Kamiokande NERFINISHED ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: K2K experiment Description of subject: The K2K experiment was a long-baseline neutrino experiment in Japan that sent a beam of muon neutrinos from KEK to the Super-Kamiokande detector, providing early accelerator-based evidence for neutrino oscillations.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.