According to, matter and anti-matter should have been created in equal amounts. 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) are created in exactly equal numbers.
It's currently estimated, however, that :
“The Standard Mode prediction for the ratio of baryons over antibaryons deviates fro 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 Leptogenesis J. Phys.: Conf. Ser. 335, 012008
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
Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.
If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !
Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.
( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)