positronium

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pos·i·tro·ni·um

 (pŏz′ĭ-trō′nē-əm)
n.
A short-lived association of an electron and a positron bound together in a configuration resembling the hydrogen atom.

positronium

(ˌpɒzɪˈtrəʊnɪəm)
n
(Atomic Physics) physics a short-lived entity consisting of a positron and an electron bound together. It decays by annihilation to produce two or three photons
[C20: from positron + -ium]

pos•i•tro•ni•um

(ˌpɒz ɪˈtroʊ ni əm)

n.
a short-lived atomic system consisting of a positron and an electron bound together.
[1945; positron + -ium2]
Translations
positronium
References in periodicals archive ?
A proposed experiment is connected to orthopositronium annihilation anomalies, which, being related to one of known unmatter entity, orthopositronium (built on electron and positron), opens a way to expand the Standard Model.
The pick-off lifetime of orthopositronium, o-Ps, is correlated to the free volume hole size in polymers (6).
Unlike a stable hydrogen atom, orthopositronium lasts only for about 140 nanoseconds, before its components annihilate each other in a burst of pure energy.
Glashow of Harvard University suggested that orthopositronium could provide a sensitive way to search for the mirror universe.
This explains why orthopositronium, where the particle (electron and positron) spins are parallel and hence the magnetic component of the electromagnetic interaction is repulsive, has a higher energy state than parapositronium where the particle spins are anti-parallel and the magnetic component of QED is attractive.
If the frequency of the density fluctuation is slower than the positron or orthoPositronium (oPs) annihilation frequency ([similar to][10.
By the mentioned new QED effect and by the new formulation of the BS equation, a term in the orthopositronium decay rate that is missing in the conventional QED is found, resolving the orthopositronium lifetime puzzle completely.
On the possibility of nuclear synthesis during orthopositronium formation.
22]Na) annihilation lifetime spectra in samples of gaseous neon of various isotopic abundance, the independent observations of the orthopositronium lifetime anomaly, and comparison of unique experimental data on the positron's annihilation lifetime spectra in condensed deuterium ([D.
This letter gives a history of two observed anomalies of orthopositronium annihilation, of which the 20th anniversary occurs this year.
Expansion of the Standard Model (SM) for the quantitative description of the orthopositronium lifetime anomalies allows formulation of additional experimental tests of supersymmetry in the final state of the positron beta-decay of nuclei such as [sup.
A proposed experiment is connected to othopositronium annihilation anomalies, which, being related to one of known unmatter entity, orthopositronium (built on electron and positron), opens a way to expand the Standard Model.