antiprotonic helium
E210169
Antiprotonic helium is an exotic, metastable atomic system in which an antiproton replaces one of helium’s electrons, making it a key laboratory for precision tests of fundamental symmetries in particle physics.
All labels observed (3)
| Label | Occurrences |
|---|---|
| antiprotonic helium canonical | 1 |
| antiprotonic helium atom | 1 |
| p̄He⁺ | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T1889305 — 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: antiprotonic helium Context triple: [ASACUSA experiment, studies, antiprotonic helium]
-
A.
helium-3
Helium-3 is a rare, light, non-radioactive isotope of helium valued for its role in nuclear fusion research and as a tracer in astrophysics and low-temperature physics.
-
B.
deuteron
A deuteron is the positively charged nucleus of deuterium, consisting of one proton and one neutron bound together.
-
C.
Bethe–Weizsäcker cycle
The Bethe–Weizsäcker cycle is a nuclear fusion process in stars, particularly massive ones, where hydrogen is converted into helium through a catalytic cycle involving carbon, nitrogen, and oxygen nuclei.
-
D.
Atom
Atom is a family of low-power x86 microprocessors developed by Intel, primarily designed for use in netbooks, embedded systems, and energy-efficient devices.
-
E.
Atom
Atom is a free and open-source text and source code editor developed by GitHub, known for its hackability, rich plugin ecosystem, and cross-platform support.
- 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: antiprotonic helium Target entity description: Antiprotonic helium is an exotic, metastable atomic system in which an antiproton replaces one of helium’s electrons, making it a key laboratory for precision tests of fundamental symmetries in particle physics.
-
A.
helium-3
Helium-3 is a rare, light, non-radioactive isotope of helium valued for its role in nuclear fusion research and as a tracer in astrophysics and low-temperature physics.
-
B.
deuteron
A deuteron is the positively charged nucleus of deuterium, consisting of one proton and one neutron bound together.
-
C.
Bethe–Weizsäcker cycle
The Bethe–Weizsäcker cycle is a nuclear fusion process in stars, particularly massive ones, where hydrogen is converted into helium through a catalytic cycle involving carbon, nitrogen, and oxygen nuclei.
-
D.
Atom
Atom is a family of low-power x86 microprocessors developed by Intel, primarily designed for use in netbooks, embedded systems, and energy-efficient devices.
-
E.
Atom
Atom is a free and open-source text and source code editor developed by GitHub, known for its hackability, rich plugin ecosystem, and cross-platform support.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
exotic atom
ⓘ
metastable atomic system ⓘ three-body atomic system ⓘ |
| annihilationChannel | antiproton–nucleon annihilation in the helium nucleus ⓘ |
| comparedWith | high-precision QED calculations ⓘ |
| createdAt |
Antiproton Decelerator
ⓘ
surface form:
Antiproton Decelerator at CERN
|
| decayMechanism | radiative de-excitation followed by annihilation ⓘ |
| describedBy | three-body quantum electrodynamics ⓘ |
| enables | comparison of proton and antiproton properties ⓘ |
| fieldOfStudy |
antimatter physics
ⓘ
atomic physics ⓘ particle physics ⓘ |
| hasAlternativeName |
antiprotonic helium
ⓘ
surface form:
antiprotonic helium atom
antiprotonic helium ⓘ
surface form:
p̄He⁺
|
| hasBindingMechanism | Coulomb interaction ⓘ |
| hasConstituent |
antiproton
ⓘ
electron ⓘ helium nucleus ⓘ |
| hasElectricCharge | neutral ⓘ |
| hasImportance |
benchmarking QED in three-body systems
ⓘ
constraining possible CPT-violating effects ⓘ |
| hasLifetime | microsecond scale for metastable states ⓘ |
| hasNetCharge | +1 for the ionic complex p̄He⁺ ⓘ |
| hasProperty |
high orbital angular momentum states
ⓘ
high principal quantum number states ⓘ long-lived metastable states ⓘ narrow spectroscopic transitions ⓘ suppressed annihilation rate ⓘ |
| hasSpectralLines |
in the ultraviolet region
ⓘ
in the visible region ⓘ |
| hasTheoreticalTreatment | high-precision few-body calculations ⓘ |
| investigatedAt | CERN ⓘ |
| investigatedBy |
ASACUSA experiment
ⓘ
surface form:
ASACUSA collaboration
laser spectroscopy ⓘ microwave spectroscopy ⓘ |
| isFormedBy | stopping low-energy antiprotons in helium gas ⓘ |
| isFormedIn |
helium-3
ⓘ
helium-4 ⓘ |
| replaces | one helium electron with an antiproton ⓘ |
| requiresSource | low-energy antiproton beam ⓘ |
| studiedFor |
precision measurements of antiproton properties
ⓘ
precision tests of CPT symmetry ⓘ precision tests of charge–parity–time reversal invariance ⓘ tests of matter–antimatter symmetry ⓘ |
| usedToMeasure |
antiproton charge-to-mass ratio
ⓘ
antiproton-to-electron mass ratio ⓘ |
| usedToTest | CPT invariance between proton and antiproton ⓘ |
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: antiprotonic helium Description of subject: Antiprotonic helium is an exotic, metastable atomic system in which an antiproton replaces one of helium’s electrons, making it a key laboratory for precision tests of fundamental symmetries in particle physics.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
antiprotonic helium atom
this entity surface form:
p̄He⁺