The Matter / Antimater Imbalance in the Universe

Physicists have long pondered the problem and may have an answer. It seems that just before the universe was one millisecond old, matter and antimatter annihilated each other in a sweeping extinction. But a tiny asymmetry was built into the universe so that matter dominated over antimatter by one part out of 100 billion. Why the built-in asymmetry? In the first 100 billion-billion-billionth of a second of the universe's history, particles called X particles and their antiparticles were create...