How the LHC will make the top quark old news
When the Large Hadron Collider begins collisions, the top quark won't have as much of a role as the star of cutting-edge physics discoveries but more as a means to ensure the machine is working properly. "There's the old saw: one man's discovery is another man's calibration," said the University of Nebraska's Ken Bloom at a press conference at the American Physical Society meeting in Denver, Colorado, last week. "Expect a lot of papers on top quark physics in the first few years of operation."
The discovery of the top quark in 1995 marks a crowning achievement of the Fermilab's Tevatron. Once the LHC has first collisions it will become just the second machine capable of producing the top quark, which is currently the most massive subatomic particle ever observed.
Bloom explained that while top quark decays are now well understood, they remain very complicated and pose challenging analyses. Observing such a complicated process and comparing the results with current understanding will calibrate the LHC.
"If you can show that you have things working in top quark events, that means you can trust things well enough to start to look for new physics," said Bloom. "And I really think you have to establish that you can do the Standard Model physics before you can credibly start looking for new physics."
Physicists at that panel also confirmed the LHC's plans to continue operating through the 2009-2010 winter. This will be the first winter that the LHC does not shut down to save on energy costs.
"It's really fabulous," says Bloom of the extended run. "We're really going to need that to shake down what we're doing."