neutral kaon system
E543037
CP-violating system
flavor oscillation system
meson system
quantum two-state system
testbed for fundamental symmetries
The neutral kaon system is a quantum two-state system of strange mesons whose weak-interaction mixing and CP-violating behavior make it a key testing ground for fundamental symmetries in particle physics.
All labels observed (1)
| Label | Occurrences |
|---|---|
| neutral kaon system canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T5766878 — 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: neutral kaon system Context triple: [K-short, isMassEigenstateOf, neutral kaon system]
-
A.
K+ (charged kaon)
K⁺ (charged kaon) is a positively charged meson containing an up quark and an anti-strange quark, notable for its role in probing weak interactions and testing the Standard Model through rare decay processes.
-
B.
Neutrino
A neutrino is an extremely light, electrically neutral elementary particle that interacts only via the weak nuclear force and gravity, making it very difficult to detect.
-
C.
High Resolution Kaon Spectrometer
The High Resolution Kaon Spectrometer is a precision magnetic spectrometer designed to detect and analyze kaons produced in nuclear and particle physics experiments.
-
D.
tau neutrino
The tau neutrino is a fundamental, electrically neutral lepton associated with the tau particle, interacting only via the weak force and gravity and playing a key role in neutrino oscillations.
-
E.
NA62
NA62 is a high-energy physics experiment at CERN designed primarily to study rare kaon decays and test the predictions of the Standard Model.
- 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: neutral kaon system Target entity description: The neutral kaon system is a quantum two-state system of strange mesons whose weak-interaction mixing and CP-violating behavior make it a key testing ground for fundamental symmetries in particle physics.
-
A.
K+ (charged kaon)
K⁺ (charged kaon) is a positively charged meson containing an up quark and an anti-strange quark, notable for its role in probing weak interactions and testing the Standard Model through rare decay processes.
-
B.
Neutrino
A neutrino is an extremely light, electrically neutral elementary particle that interacts only via the weak nuclear force and gravity, making it very difficult to detect.
-
C.
High Resolution Kaon Spectrometer
The High Resolution Kaon Spectrometer is a precision magnetic spectrometer designed to detect and analyze kaons produced in nuclear and particle physics experiments.
-
D.
tau neutrino
The tau neutrino is a fundamental, electrically neutral lepton associated with the tau particle, interacting only via the weak force and gravity and playing a key role in neutrino oscillations.
-
E.
NA62
NA62 is a high-energy physics experiment at CERN designed primarily to study rare kaon decays and test the predictions of the Standard Model.
- F. None of above. chosen
Statements (50)
| Predicate | Object |
|---|---|
| instanceOf |
CP-violating system
ⓘ
flavor oscillation system ⓘ meson system ⓘ quantum two-state system ⓘ testbed for fundamental symmetries ⓘ |
| consistsOf |
K0 meson
GENERATED
ⓘ
anti-K0 meson GENERATED ⓘ |
| decaysVia |
semileptonic decays
GENERATED
ⓘ
three-pion final states GENERATED ⓘ two-pion final states GENERATED ⓘ |
| exhibits |
CP violation
GENERATED
ⓘ
T violation GENERATED ⓘ direct CP violation GENERATED ⓘ indirect CP violation GENERATED ⓘ |
| hasApproximateSymmetry | CP symmetry in the limit ε → 0 GENERATED ⓘ |
| hasComponent |
K0 (down anti-strange)
GENERATED
ⓘ
anti-K0 (strange anti-down) GENERATED ⓘ |
| hasEffectiveEigenstate |
KL (long-lived neutral kaon)
GENERATED
ⓘ
KS (short-lived neutral kaon) GENERATED ⓘ |
| hasObservable |
CP-violating parameter epsilon (ε)
GENERATED
ⓘ
decay width difference ΔΓ between KS and KL GENERATED ⓘ direct CP-violating parameter epsilon-prime (ε′) GENERATED ⓘ mass difference Δm between KS and KL GENERATED ⓘ |
| hasProperty |
flavor eigenstates differ from mass eigenstates
GENERATED
ⓘ
mass eigenstates KS and KL have different lifetimes GENERATED ⓘ mass eigenstates KS and KL have slightly different masses GENERATED ⓘ non-Hermitian effective Hamiltonian for decays GENERATED ⓘ |
| hasQuantumNumber |
isospin I = 1/2
GENERATED
ⓘ
spin 0 GENERATED ⓘ strangeness S = +1 for K0 GENERATED ⓘ strangeness S = −1 for anti-K0 GENERATED ⓘ |
| hasTheoreticalTool | density matrix formalism for decoherence studies GENERATED ⓘ |
| isDescribedBy |
Weisskopf–Wigner approximation
GENERATED
ⓘ
effective 2×2 Hamiltonian formalism GENERATED ⓘ standard model of particle physics GENERATED ⓘ |
| isGovernedBy |
electromagnetic interaction (for some decays)
GENERATED
ⓘ
strong interaction (for production and hadronization) GENERATED ⓘ weak interaction GENERATED ⓘ |
| isPrototypeFor | other neutral meson mixing systems (Bd, Bs, D0, B0s) GENERATED ⓘ |
| isUsedIn |
precision tests of quantum mechanics
GENERATED
ⓘ
searches for physics beyond the standard model GENERATED ⓘ |
| isUsedToTest |
CP symmetry
GENERATED
ⓘ
CPT symmetry GENERATED ⓘ T symmetry GENERATED ⓘ unitarity of the CKM matrix GENERATED ⓘ ΔS = ΔQ rule in weak decays GENERATED ⓘ |
| undergoes | K0–anti-K0 mixing GENERATED ⓘ |
| wasCentralTo | discovery of CP violation in 1964 GENERATED ⓘ |
| wasStudiedAt |
Brookhaven National Laboratory
GENERATED
ⓘ
CERN kaon experiments GENERATED ⓘ |
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: neutral kaon system Description of subject: The neutral kaon system is a quantum two-state system of strange mesons whose weak-interaction mixing and CP-violating behavior make it a key testing ground for fundamental symmetries in particle physics.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.