Antimatter mystery transcends new data

Physicists have finally answered a decades-old question about the difference between matter and antimatter. Yet their finding only deepens the mystery of why the universe contains so much more matter than antimatter.

Last week, researchers at the Stanford (Calif.) Linear Accelerator Center (SLAC) announced they had proved that hefty subatomic particles, known as B mesons and anti-B mesons, decay into lighter particles in slightly different ways.