The Higgs' proposed role in both theory and the actual universe is critical. Without it, the Standard Model that has been exquisitely successful in describing and predicting the universe's menagerie of particles falls short of explaining why they -- and by extension we -- have any mass at all.
Researchers at today's particle accelerators, of which the U.S.-based Tevatron is the most powerful, have long hoped to find evidence of the Higgs. But most physicists have pinned their expectations on CERN's $8 billion Large Hadron Collider, or LHC, now being built in Switzerland, scheduled after recent delays to begin operations next spring.
The political fragility of this project, and of a similarly priced International Linear Collider still in the planning stages, have led some commentators to argue that finding the Higgs today would be disastrous for physics, undermining the rationale for the new facilities. Other researchers have called this nonsense, saying any discovery would open up new avenues of research possible only with the new colliders.
Many physicists discount the rumors strictly on experimental grounds, however.
Particle accelerator experiments inherently throw up what physicists call statistical fluctuations. Essentially, this means that in every hundred collisions, a mildly unusual blip in the data will show up. Every 1,000 instances, a more significant, but still meaningless blip will show, and so on.
According to the unconfirmed rumors, the Fermilab results show a fairly high degree of statistical significance, which -- if true -- is unusual. But even strong observations can wind up being explained as strong fluctuations, or fluctuations combined with modeling errors, not real breakthroughs, physicists note.
Other scientists note a historical trend: Researchers at experiments nearing the end of their lives often tend to uncover suggestive data, which argue for extending the experiments' operation. In one recent example, work at CERN's Large Election-Positron collider, which had to be shut down to make way for the LHC, was extended in 2000 to investigate data that also raised hopes of a Higgs discovery.
Tevatron has plans and funding to work through the end of 2009, and thus is in no danger of immediate closure. But the opening of the LHC next year will undeniably shift the field's center of gravity to the European facility, away from Fermilab.
Whatever the final outcome, the weeks of rumors and response say more about the sociology of science than about science itself. The hard physics will come only when (and if) data is released, and the business of testing, interpreting and re-analyzing begins.
"It's a lot like looking for an ivory-billed woodpecker," said University of Wisconsin-Madison physicist Dick Loveless, whose LHC experiment that's due to start next year also stands a chance of finding the Higgs. "Was it seen? Can you prove it?"