A quick refresher course for those unfamiliar with the conundrum of matter/antimatter asymmetry in our universe. A long time ago, when our universe was still in its earliest birthing throes, matter and antimatter were colliding and annihilating each other out of existence constantly. This process slowed down as our universe gradually cooled, but there should have been equal parts matter and antimatter - and there weren't. Instead, there were slightly more matter particles than antimatter.
We know this because we can see the remnants of the survivors of that cosmological Octagon all around us: every bit of matter in our observable universe, from galaxies to dust mites and everything in between, exists because matter won that long-ago war of attrition. And physicists have no idea why that asymmetry should have existed in the first place. It's one of the Big Questions they hope the LHC can help answer.
Technically, it's known as CP (charge-parity) violation, an effect first proposed by Russian physicist Andrei Sakharov, in which "when the charges and spins of particles are reversed, they should behave slightly differently." This isn't the first glimpse of CP violation in the subatomic realm, but prior observed asymmetries haven't been large enough to explain how our material world could exist. According to the New York Times‘ Dennis Overbye: