A rare particle containing equal parts weird antimatter and normal matter has popped up in experiments at the world's largest particle accelerator.
Scientists recently observed new behavior of this particle, called a B meson, at the Large Hadron Collider (LHC) atom smasher, a 17-mile long (27-km) underground ring at the CERN laboratory near Geneva. B mesons are made up of one quark (the building block of protons and neutrons) and one anti-quark, which is the antimatter partner to the quark. [The Strangest Little Things in Nature]
All normal particles are thought to have antimatter partner particles with the same mass but opposite charge. When matter and antimatter meet, the two annihilate each other. Scientists think the universe started out with equal amounts of both, but most of the antimatter was destroyed by matter, and whatever surplus of matter remained is what makes up the universe we know today. The question of why the universe started out with more matter than antimatter has haunted physicists for years.