Why is there more matter than antimatter in the universe?

The answer

The matter-antimatter asymmetry, called baryogenesis, is one of physics' deepest mysteries. The Big Bang should have produced equal quantities of matter and antimatter, resulting in mutual annihilation and a universe of pure energy. Instead, roughly one extra matter particle per billion survived. The Standard Model's CP violation - where matter and antimatter behave slightly differently - is insufficient to explain the observed imbalance by many orders of magnitude. Experiments at CERN's LHCb detector discovered new CP violation in charm quarks in 2019. The T2K and NOvA neutrino experiments are investigating whether neutrinos violate CP symmetry differently, which could explain the excess. The BASE experiment at CERN measures antimatter with extreme precision, finding matter-antimatter symmetry to 16 decimal places.