If tracking down a Higgs boson were easy, scientists would've found it by now. So how do you find a Higgs particle? Well, the Caltech team will use the world's largest particle accelerator, the Large Hadron Collider (LHC) being built near Geneva, Switzerland, by the European High Energy Physics Laboratory. The LHC is expected to go online in 2006. In the meantime, a massive amount of prep work is being done to manage and analyze the data and to perfect the detectors. Catching a Higgs boson will require more than flipping a giant "on" switch.

The LHC is a circular vacuum tube in an underground tunnel about 17 miles in circumference. To flush out new subatomic particles, proton beams are fired around the LHC at nearly the speed of light. The beams cross at one of four interaction areas, allowing protons to smash into one another. The more focused the energy of those collisions, the smaller the component parts revealed. The LHC will be at least 10 times more powerful than any other particle accelerator ever built, and it is expected to be the first to produce a Higgs boson.

When the LHC is running, proton bunches circulating in the tunnel will meet 40 million times per second, but at each meeting only about 20 proton collisions will occur. Still, that makes for about 800 million collisions per second. Most of the time, protons will only

graze each other. The creation of a Higgs particle will require a head-on collision, and a variety of other conditions will have to be just right. But once in every 10 trillion collisions—which will be about once a day in the LHC's proton demolition derby—one should appear.