BABAR

Something is missing in physicists' understanding of how the universe evolved into its current state. At the big bang, equal quantities of matter and antimatter should have been created and subsequently annihilated each other, leaving nothing but energy. However the matter universe is here as undeniable proof of the victory of matter over antimatter in this initial cosmic encounter. To establish experimentally how matter came to dominate is a central theme in particle physics research. The BaBar experiment at SLAC is working relentlessly to tie down an exact measurement of this effect called Charge Parity (CP) violation.

BaBar follows the infinitesimally short lives—a trillionth of a second—of particles called B mesons and those of their antimatter counterparts, anti-B mesons or "B-bars." Any difference in behavior of these otherwise exact opposites indicates a difference between matter and antimatter and confirms the existence of CP violation. BaBar's first results, announced in the summer of 2001, gave clear evidence for CP violation in B mesons. BaBar data continues to provide new levels of understanding of the matter antimatter symmetry.

The success of BaBar is based on the power and efficiency of collaborative science. More than 500 scientists and engineers from 75 institutions in Canada, China, France, Germany, Italy, the Netherlands, Norway, Russia, Spain, the United Kingdom, and the United States are working on BaBar.