positronium
E761922
Positronium is an exotic, hydrogen-like atom consisting of an electron and its antiparticle, a positron, bound together before they annihilate into photons.
All labels observed (1)
| Label | Occurrences |
|---|---|
| positronium canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T8832406 — 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: positronium Context triple: [GBAR, uses, positronium]
-
A.
antiprotonic helium
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.
-
B.
The Electron
"The Electron" is a landmark early 20th-century scientific work by Robert A. Millikan that details his experimental determination of the electron’s charge and explores the fundamental nature of this subatomic particle.
-
C.
Fermyon
Fermyon is a technology company focused on building tools and platforms for serverless and cloud-native applications using WebAssembly.
-
D.
deuteron
A deuteron is the positively charged nucleus of deuterium, consisting of one proton and one neutron bound together.
-
E.
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.
- 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: positronium Target entity description: Positronium is an exotic, hydrogen-like atom consisting of an electron and its antiparticle, a positron, bound together before they annihilate into photons.
-
A.
antiprotonic helium
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.
-
B.
The Electron
"The Electron" is a landmark early 20th-century scientific work by Robert A. Millikan that details his experimental determination of the electron’s charge and explores the fundamental nature of this subatomic particle.
-
C.
Fermyon
Fermyon is a technology company focused on building tools and platforms for serverless and cloud-native applications using WebAssembly.
-
D.
deuteron
A deuteron is the positively charged nucleus of deuterium, consisting of one proton and one neutron bound together.
-
E.
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.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
bosonic system
ⓘ
exotic atom ⓘ hydrogen-like atom ⓘ |
| analogousTo | hydrogen atom ⓘ |
| annihilatesInto | photons ⓘ |
| bindingEnergyRelativeToHydrogen | half the binding energy of hydrogen ⓘ |
| bindingInteraction | electromagnetic interaction ⓘ |
| BohrRadiusRelativeToHydrogen | twice the Bohr radius of hydrogen ⓘ |
| canFormIn |
biological tissue
ⓘ
gases ⓘ liquids ⓘ solids ⓘ vacuum ⓘ |
| composedOf |
electron
ⓘ
positron ⓘ |
| discoveredBy | Martin Deutsch ⓘ |
| discoveryYear | 1951 ⓘ |
| governedBy | quantum electrodynamics ⓘ |
| hasElectricCharge | 0 ⓘ |
| hasExcitedStates |
2P
ⓘ
2S ⓘ |
| hasGroundState | 1S ⓘ |
| hasQuantumNumber |
magnetic quantum number m
ⓘ
orbital angular momentum l ⓘ principal quantum number n ⓘ total angular momentum J ⓘ total spin S ⓘ |
| hasReducedMass | half the electron mass ⓘ |
| hasSpectralLinesSimilarTo | hydrogen spectral lines ⓘ |
| hasSpinConfiguration |
ortho-positronium
ⓘ
para-positronium ⓘ |
| hasTotalMass | approximately twice the electron mass ⓘ |
| isBoundStateOf | electron and positron ⓘ |
| isElectricallyNeutral | true ⓘ |
| isMetastable | true ⓘ |
| lifetimeAffectedBy | surrounding medium ⓘ |
| lifetimeDependsOn | spin state ⓘ |
| orthoPositroniumDecayProducts | three gamma photons ⓘ |
| orthoPositroniumLifetimeInVacuum | about 142 nanoseconds ⓘ |
| orthoPositroniumSpin | triplet (total spin 1) ⓘ |
| paraPositroniumDecayProducts | two gamma photons ⓘ |
| paraPositroniumLifetimeInVacuum | about 125 picoseconds ⓘ |
| paraPositroniumSpin | singlet (total spin 0) ⓘ |
| relevantTo | positron emission tomography ⓘ |
| studiedIn | positron annihilation spectroscopy ⓘ |
| usedIn |
fundamental symmetry tests
ⓘ
materials porosity studies ⓘ |
| usedToTest | quantum electrodynamics predictions ⓘ |
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: positronium Description of subject: Positronium is an exotic, hydrogen-like atom consisting of an electron and its antiparticle, a positron, bound together before they annihilate into photons.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.