Observations of early universe hint at a giant excess of anti-neutrinos
Thursday, March 21, 2013 - 11:01
in Physics & Chemistry
(Phys.org) —Scientists have a great deal of evidence to support the fact that the universe contains much more baryonic matter than baryonic anti-matter, a phenomenon known as baryon asymmetry. Baryons, which are defined as being made of three quarks, include protons and neutrons and make up the bulk of the atomic matter that we're familiar with in everyday life. But much less is known about the possibility of a lepton asymmetry, in which there are unequal amounts of leptons and anti-leptons in the universe. The best known examples of leptons are electrons and neutrinos. Neutrinos in particular are much harder to detect than baryons because they're much lighter, and so much less energetic.