By Zeeya Merali

It hasn't even been found yet, but the elusive Higgs particle is already generating controversy. As feelings run high over a recent conference in France, the particle physics community is split over who should get credit out of the six theoretical physicists who developed the mechanism behind its existence.

The Higgs particle is predicted to exist as part of the mechanism believed to give particles their mass, and is the only piece of the Standard Model of particle physics that remains to be discovered. Physicists at both the Large Hadron Collider at CERN, Europe's premier particle physics laboratory near Geneva in Switzerland, and the Tevatron accelerator in Batavia, Ill., recently voiced their expectation that the particle could well be detected within the next few years.

This gave new urgency not only to the race to find the particle, but also to establishing authorship of the ideas behind it. As John Ellis, a particle physicist based at CERN, acknowledges: "Let's face it, a Nobel prize is at stake."

The authorship question is fraught because the mechanism was developed independently by three groups within a matter of weeks in 1964. First up were Robert Brout and François Englert in Belgium, followed by Peter Higgs in Scotland, and finally Tom Kibble in London, along with his colleagues in the United States, Gerald Guralnik (at the time in London) and Carl R. Hagen.

"There are six people who developed the mechanism in quick succession and who hold a legitimate claim to credit for it," says particle physicist Frank Close at the University of Oxford, UK.

Because the Royal Swedish Academy of Sciences can award Nobel prizes to no more than three people, that leaves six men in contention for half as many places, should the particle make an appearance.

"The first three in the Nobel queue probably feel quite relaxed--all they have to do is stay alive until the particle is discovered," says Ellis. "The ones just behind them may understandably be quite nervous."

Stoking the fire

The credit controversy was re-ignited by an advertisement for the "Higgs Hunting" meeting that took place in Orsay, France, last week. Many particle physicists took exception to the fact that the meeting's advertisement on the web credited only Brout, Englert and Higgs, with some threatening to either boycott the meeting or formally protest while there, says Daniel Ferrante, a physicist at Syracuse University in New York and a former student of Guralnik's.

One of the meeting's organizers, Gregorio Bernardi at the Laboratory of Nuclear and High Energy Physics in Paris, admits that the committee was surprised by the strength of objections leveled at the web advertisement. "People took this very seriously, which we didn't expect," he says.

However, the committee felt that the meeting should not be politicized. "We were not happy that we were lobbied very strongly to change our ad--it was not appropriate," Bernardi says.

Ellis advised the committee to stick to their guns, arguing that it is undeniable that Guralnik, Hagen and Kibble were the last to publish. He also notes that their paper cited the earlier publications by Brout and Englert, and by Higgs, weakening their authorship claim.

That argument carries little weight with particle physicist Tom Ferbel at the University of Rochester in New York, who says that Guralnik, Hagen and Kibble should not be penalized for citing other papers out of professional courtesy.

Ferbel also notes that, earlier this year, the American Physical Society decided to award all six men the J. J. Sakurai Prize for Theoretical Particle Physics, making the snub by the conference organizers "insulting" and "chilling." "I do fear that the myopic views of the organizers could definitely impact the decisions of the Swedish Academy," Ferbel says.

The conference organizers acknowledged that their choice was controversial by inviting a special talk on the tangled history of the mechanism, providing a forum for disgruntled conference participants to debate the matter. However, although the meeting ultimately ran smoothly, it seems likely that arguments over this issue will become more heated now that the Higgs particle is perceived to be within reach.

"There is a lot of fuss being made about Guralnik, Hagen and Kibble right now, and the American physics community seems to be listening," says Ellis. "I'm just glad that I'm not on the Nobel committee deciding who to throw out of the lifeboat."