IN THE end, it had to go. The ageing Large Electron Positron Collider teased
researchers into thinking they had seen physics鈥檚 greatest prize鈥攖he Higgs
boson. But when LEP failed to pin it down, CERN, Europe鈥檚 particle factory near
Geneva, decided to dismantle it to make way for the next-generation
collider.
During its final few months in the summer, LEP ran at its highest possible
energy. Then, in the particle tracks produced by its high-energy collisions,
researchers saw signs of what could be the Higgs鈥攖he particle thought to
give all other particles their mass. This spurred the researchers to plead for
an extra month of beam time in September. They were driven by fears that the
prize would be handed to Fermilab near Chicago, their greatest rival. But the
evidence turned up in Europe during that month was not quite enough for a
positive identification. The researchers then asked for LEP to be kept running
for another year.
The cards were stacked against them. Construction workers were waiting to
dismantle the accelerator to make way for its replacement, the 拢1.5
billion Large Hadron Collider (LHC), in the same 27-kilometre tunnel straddling
the French-Swiss border.
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On 8 November, CERN director-general Luciano Maiani decided not to risk a
delay in building the LHC, scheduled to switch on in 2005. LEP is now being
dismantled. 鈥淚t鈥檚 very sad,鈥� says Tizano Camporesi, spokesperson for the team
working with the collider鈥檚 Delphi detector. 鈥淵ou can hear the chopping of the
cables when you walk into the detector pits.鈥�
LEP is not short of laurels. During its 11-year career it nailed down many
details of the W and Z bosons, particles essential to unifying the
electromagnetic and weak forces. It also proved that quarks come in only six
flavours, all of which have now been discovered. Nabbing the Higgs, however,
would have shot the collider to even greater fame. Bitterly disappointed, LEP
researchers posted hundreds of anonymous comments on the Web page of CERN
physicist Patrick Janot.
鈥淭o back out on the threshold of a major discovery is comparable to a soldier
refusing battle in the face of the enemy,鈥� one writes. Another laments, 鈥淭he
Higgs is probably the last discovery in particle physics I鈥檒l witness during my
lifetime. Please go find it soon.鈥� One asks bluntly: 鈥淒o you really want to
leave the Higgs boson to the Fermilab guys?鈥�
For their part, Fermilab researchers are downplaying their opportunity. The
revamped Tevatron collider at Fermilab comes back online in March. If the Higgs
has the mass that the LEP researchers believe, then discovery could be just
months away. But, then, if the Tevatron falters, the honours could eventually be
passed back to CERN. 鈥淚f the Tevatron doesn鈥檛 see the Higgs,鈥� says Fermilab
physicist Marcela Carena, 鈥渢he LHC will see it sooner or later.鈥�
