If confirmed a new subatomic particle would be one of the most interesting things to come out of the low energy BaBar particle factory.

It's named BaBar because it's optimized for B Bbar particle interactions. In particle physics the notation of "bar" or just an underscore is standard for anti-particles. This particular accelerator/detector is optimized for "B" quarks (either called "bottom" or "beauty" quarks).

New Subatomic Particle -- Press Release Dated April 28, 2003