2010 Science News: On the Preponderance of Matter

Two scientists checking equipment in the central tube of the LHC. Photo by Antonio Saba courtesy of CERN Related Links Large Hadron Collider Primer on the Physical Sciences 2010 Year in Review 2010 Science News

Why Is the Universe Composed of Matter?

A great mystery of the universe is why there is a preponderance of matter over antimatter, and the corollary: how we exist. Based on particle physics' Standard Model, the Big Bang should have produced matter and antimatter in equal amounts. These two would then have destroyed each other, and life as we know it would not exist. Our existence, then, implies the necessity of a new physics—a new physics that scientists now say is being revealed in the results of proton collisions produced at the Fermi National Accelerator Laboratory (Fermilab).

Confirming the New Physics

The scientific community—and the larger world—now look to CERN's Large Hadron Collider—a particle accelerator that is bigger and stronger and faster than Fermilab's—to confirm what so far has only been hinted at: the existence of a particle to explain our matter-heavy universe.

As the LHC works at top speeds, the scientists will be watching for particles called muons, which are sort of fat electrons, to see if they are produced in greater quantity than anti-muons. Inside Fermilab's accelerator, the muon pairs outnumbered the anti-muon pairs by 1%.

Then there are the neutral B-mesons, which are flip-floppers, constantly (as in trillions of times each second) oscillating between states of matter and antimatter. These mesons display a preference toward a matter state. Both the muons and the mesons, then, might contribute to what is called the matter dominance of our universe. What causes the odd behavior of these particles? We will just have to ramp up the LHC and keep our eyes on the moving particles to find out.