No Stay of Execution for LEP

8 November 2000 7:00 pm

In the end, the future of the European Laboratory for Particle Physics (CERN) was almost as difficult to decide as the next U.S. president. In September, the laboratory's massive Large Electron Positron Collider (LEP) was due to be shut down and dismantled. But data gathered over the summer suggested that it might have a chance of bagging the Higgs boson, a prized theoretical particle. That possibility earned LEP a 1-month reprieve to gather additional data. Last week LEP scientists presented that data to CERN's management, and argued that the case for the Higgs was good enough to merit a year-long reprieve for LEP. But in a series of deadlocked meetings the data failed to convince the management: Earlier today, CERN's director-general announced that LEP should be scrapped as originally planned.

The reason for the shutdown is simple. LEP and the detectors that sit on it have to be dismantled and hauled out of a 27-kilometer-long tunnel and ancillary caverns to allow CERN to begin installing its future centerpiece, the Large Hadron Collider (LHC). For LEP's last hurrah, CERN scientists this year cranked the machine's beam energies beyond their prescribed limit. The move unexpectedly produced those tantalizing signs of Higgs bosons. These in turn resulted in LEP's extended lease on life, which expired on 2 November.

After sifting through the extra month's worth of data, LEP's science committee on 3 November concluded that the evidence LEP was producing had improved--but that the chances were still only fifty-fifty to find the sought-after bosons. The committee concluded it was worth running LEP for an extra year at a cost of around $62 million. But the committee did not feel able to say that it would be worth the costs--both financial and political--entailed in delaying the LHC's construction. Faced with the question of whether to postpone the LHC a year, the committee split straight down the middle.

Yesterday in Geneva a higher level committee called the research board met to discuss the matter. Sources told Science that board members drawn from CERN's management team were against any extension; those representing the experiment committees, and some of the lab's specialist divisions, were in favor. With the research board thus also split, CERN director-general Luciano Maiani contacted some of the representatives of 20 member states who sit on CERN's council and have ultimate authority over CERN's programs and budget. Then he gave the thumbs down.

The decision is expected to be finalized next month when the full CERN council meets. Until then, LEP and its experiments will remain shuttered--but untouched.

Related site

CERN press release about the shutdown

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