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content:physics:cosmology:antimatter

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

The Antimatter Problem

According to Big Bang Theoryplugin-autotooltip__plain plugin-autotooltip_bigBig Bang theory

There is now a large body of evidence (from different sources) to support the Big Bang Theory for the origin of the universe, but the problem remains as to the origin of the material or energy which initialised it.

As the UK’s Astronomer Royal Martin Rees has put it :
, matter and anti-matter should have been created in equal amounts at the 'beginning' of the Universe. And, in experiments with high-energy particle accelerators, that is exactly what happens. Baryons (i.e. 'heavy' particles such as neutrons, protons, and their constituent quarks) and their anti-particle equivalents (anti-baryons) are created in equal numbers.

It's currently estimated, however, that (in 'natural' conditions outside the laboratory) :

The Standard Mode prediction for the ratio of baryons over antibaryons deviates from the astrophysical observations by eight orders of magnitude."

Source; Proceedings, 26th International Nuclear Physics Conference (INPC2016)

There could be areas of the universe where antimatter dominates - but no observations have so far identified regions in space where antimatter and matter encounter each other - catastrophic zones which would be easily detectable due to the radiation that would be produced.

To compound the mystery :

Theories that explain this apparent asymmetry violate other measurements."

Source : NASA AMS-02 project.

Further reading: New Scientist , April 2009

For technical info, see : Baryogenesis and Leptogenesisopen access J. Phys.: Conf. Ser. 335, 012008

Matter/antimatter asymmetry tests at CERN

New research conducted at CERN has attempted to find fundamental differences between protons and anti-protons. Without success. Finding asymmetries could explain how one form (matter) is dominant in the universe.

See: Riddle of matter remains unsolved: Proton and antiproton share fundamental properties Press release, Johannes Gutenberg-Universität Mainz, Oct. 2017


Also see : Antimatter and gravityplugin-autotooltip__plain plugin-autotooltip_bigAntimatter and gravity

resolved

The 'Resolved' category archives questions which have been answered since they were added to the site.

As of Sep. 2023, this entry is now moved to the 'Resolved' section.

A recent set of experiments at CERN, which created thousands of 'antihydrogen' atoms (anti-protons with orbiting positrons), and then 'dropped' them down a 3m high column, have proved for the first tiime that the anti-atoms

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