Di-positronium

Di-positronium, or dipositronium, is a molecule consisting of two atoms of positronium. It was predicted to exist in 1946 by John Archibald Wheeler,^[1] and subsequently studied theoretically, but was not observed until 2007 in an experiment done by David Cassidy and Allen Mills at the University of California, Riverside. The researchers made the positronium molecules by firing intense bursts of positrons into a thin film of porous silicon dioxide. Upon slowing down in the silica, the positrons captured ordinary electrons to form positronium atoms. Within the silica, these were long lived enough to interact, forming molecular di-positronium.^[2]

See also

• Hydrogen molecule
• Hydrogen molecular ion

References

1. ^ J. A. Wheeler, Polyelectrons, Annals of the New York Academy of Sciences 48, #3 (1946), pp. 219–238.
2. ^ Cassidy, D. B.; Mills, Jr., A. P. (2007-09-13), "The production of molecular positronium", Nature 449 (7159): 195–197, Bibcode 2007Natur.449..195C, doi:10.1038/nature06094, PMID 17851519 

External links

• Molecules of Positronium Observed in the Laboratory for the First Time, press release, University of California, Riverside, September 12, 2007.
• Mirror particles form new matter, Jonathan Fildes, BBC News, September 12, 2007.