Understanding the Cosmic Mystery: Antimatter and CP Symmetry Violation
• Antiparticles, a ‘partner’ of a particle type with the same mass but opposite charge, are an enigmatic fact about the natural world.
• They are an inevitable consequence of describing the world in terms of quantum mechanics and special relativity.
• Antiparticles are detectably numerous, with our bodies producing one antielectron every 20 seconds from the decay of potassium-40.
• Cosmic rays supply antiprotons, antielectrons, and even antinuclei.
• Antimatter’s scarcity is evident in the universe as all galaxies are made of matter, not antimatter.
• In 1964, American physicists James Cronin and Val Fitch discovered that CP symmetry is violated, but not all the time.
• Makoto Kobayashi and Toshihide Maskawa found that if there were at least three variants of every quark species, CP symmetry violation is unavoidable.
• Soviet physicist Andrei Sakharov realized that CP symmetry violation is essential for creating matter-antimatter asymmetry in the early universe.
• A mechanism proposed in August 2024 brings one of the three Sakharov conditions within the reach of the Standard Model five decades since their discovery.