In recent years the U.S. national laboratories have laid out an ambitious research agenda for particle physics. About 170 scientists and engineers at the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Ill., have been developing designs and technologies for the International Linear Collider (ILC), a proposed machine that would explore the frontiers of high-energy physics by smashing electrons into their antimatter counterparts [see "Building the Next-Generation Collider" by Barry Barish, Nicholas Walker and Hitoshi Yamamoto; SCIENTIFIC AMERICAN, February 2008]. Another 80 researchers at Fermilab have been finalizing the plans for NOvA, a giant detector in northern Minnesota that could answer fundamental questions about the neutrino, a particle that is ubiquitous but maddeningly elusive. But on December 17, 2007—a date that scientists quickly dubbed "Black Monday"—Congress unexpectedly slashed funding for ILC and NOvA, throwing the future of American physics into doubt.
What made the cutbacks so devastating was that President George W. Bush and Congress had promised substantial budget increases for the physical sciences earlier in 2007. In the rush to trim the 2008 spending bill enough to avert a presidential veto, however, legislative leaders excised $88 million from the U.S. Department of Energy's funding for high-energy physics. Fermilab's 2008 budget abruptly shrank from $372 million to $320 million.
Fermilab isn't the only physics facility devastated by the recent budget cuts. Congress eliminated the $160 million U.S. contribution to ITER, the international project to build an experimental fusion reactor, as well as the 2008 funding for the Stanford Linear Accelerator Center (SLAC) in Menlo Park, Calif., which was collaborating with Fermilab in the planning of the ILC. The cuts will force SLAC to lay off 125 employees and to prematurely end its BaBar experiment (also known as the B-factory), which is looking for violations of charge and parity symmetry in the decay of short-lived particles called B mesons.
Fermilab’s director, Pier Oddone, announced that the lab would need to lay off 200 employees, or about 10 percent of its workforce, and that the remaining researchers would have to take off two unpaid days per month. These measures would allow the lab to keep operating the Tevatron, its phenomenally successful proton–antiproton collider, which is now racing to find evidence of new particles and extra dimensions before the more powerful European accelerator, the Large Hadron Collider (LHC), begins operations later this year. But the ILC and NOvA were expected to become the major focuses of research at Fermilab after the shutdown of the Tevatron, due to occur by 2010, and now the investigators in those projects must be assigned to different efforts or dismissed. "The greatest impact is on the future of the lab," Oddone says. "We have no ability now to develop our future."
A big part of that envisioned future is the proposed ILC, a 31-kilometer- (20-mile-) long facility [see image above] that would be able to detail the properties of any new particles discovered by the Tevatron or the LHC. American physicists had taken a leading role in the international effort to develop the collider, but the sudden cutoff in funding reduces the chances that the machine will be built on U.S. soil. "The ILC will go forward, but the U.S. will fall behind," says Barry Barish, director of the global design effort for the collider. The project is expected to yield technological advances that could benefit medical accelerators and materials science, and Barish says the U.S. may become less competitive in these fields if American support for the ILC is not restored.
The NOvA project is further along than the ILC; in fact, before the funding cuts were announced, the program managers had planned to upgrade the roads to their Minnesota site this spring so they could begin delivering construction materials for their enormous neutrino detector, which will weigh 15,000 tons when completed. Neutrinos come in three flavors—electron, muon and tau—and the particles constantly oscillate from one flavor to another; the NOvA detector is intended to measure how many of the muon neutrinos generated at Fermilab transform to electron neutrinos by the time they reach northern Minnesota. The results could reveal the answer to a longstanding mystery: why our universe is dominated by matter rather than antimatter.
Although NOvA has not been canceled, the suspension of funding may lead some of its scientists to abandon the effort. "The question is whether you can put a project on mothballs for a year and bring it back again," says Mark Messier of Indiana University, one of the spokesmen for NOvA. "The signal this sends is, 'Go do your research somewhere else.'"