February 17, 2012 | 11
V ANCOUVER—Last fall, the Tevatron accelerator at Fermilab in Illinois shut down for good. The long-running accelerator had been eclipsed by the vastly more powerful Large Hadron Collider outside of Geneva, Switzerland, which since 2010 has been generating data at an impressive rate. The move appeared to quash any hopes that Fermilab had of discovering the Higgs boson, the last great known unknown of modern particle physics.
Yet according to Rob Roser, the leader of the CDF experiment at the Tevatron, we shouldn’t count Fermilab out quite yet. Though the machine is no longer generating data, physicists have not had time to properly analyze all the data that has been collected thus far. Today at the annual meeting of the American Association for the Advancement of Science, Roser announced that Fermilab will reveal its final Higgs results in March. “We will be able to say something interesting,” he said, “though whether it is that we don’t see it or we do see it remains to be seen.”
Asked to clarify, Roser said that if the Higgs has a mass of around 125 gigaelectron volts—the mass that recent LHC results seem to indicate is most likely—the Tevatron would be able to identify the Higgs with “three-sigma” certainty. This is a statistical term that indicates the finding only has a tenth of a percent chance of being due to a random statistical fluctuation. Such a result would still fall short of being considered a “discovery,” however, as the field of particle physics has adopted the more stringent five-sigma standard—a one-in-a-million chance.
Another soon-to-come announcement from Fermilab will also illuminate the hunt for the Higgs. On February 23, the CDF experiment will announce a new, more precise result for the mass of the W boson. “And if you know the mass of the W and the top [quark],” said Roser, “you will know the Higgs mass perfectly.” Even if the Tevatron can’t lay claim to discovering the Higgs, its last revelations will show the rest of the world where to look.
Image courtesy of Fermilab / Reidar Hahn