TAKAYAMA, Japan -- As Japanese and American scientists basked in the glow of their monumental discovery of neutrino mass, announced here on Friday, a financial cloud that could hamper future research hung over the 120-member team on Saturday.
Through the team's leader, Dr. Yoji Totsuka, the scientists appealed for the Japanese government's reconsideration of major cuts in financing for the Kamioka Neutrino Observatory, where the discovery of neutrino mass was made. Many of the 300 physicists attending an international neutrino meeting here predicted privately that the discovery could eventually be rewarded with one or more Nobel Prizes.
But the government has been unsympathetic, Totsuka said in an interview. Faced with severe budget problems, he said, the government has reduced the Kamioka group's spending by 15 percent and threatens another 15 percent cut next year.
"This may mean shutting down the detector for up to six months, which would have devastating effects on our research," Totsuka said. he experiment announced on Friday demonstrated that neutrinos created by the impact of cosmic rays on the earth's upper atmosphere "oscillate," or change from one type to another as they reach the ground and pass through the earth. With this discovery, the observatory demonstrated beyond reasonable doubt that neutrinos have mass.
That will require revision of the generally accepted theory of the structure of matter, which is made of quarks, leptons and force-carrying particles. Depending on how large the still-unmeasured mass of neutrinos may be, they could prove to be a significant proportion of the mass of the universe, perhaps accounting for some of the "dark matter" that has not been seen directly but exerts large gravitational effects.
An American member of the Kamioka research collaboration, Dr. James Stone of Boston University, said its big underground neutrino detector, Super-Kamiokande, was investigating a range of major physics problems other than the search for neutrino oscillations on earth.
One project explores the possibility that protons -- building blocks of matter -- may decay. Super-Kamiokande, essentially a water tank the size of a 10-story building deep under western Japan's mountains near here, is also looking for an explanation of the deficit in neutrinos detected from the sun, a problem not solved by Friday's announcement.
The detector also continuously looks for bursts of neutrinos
coming from supernova explosions and peculiar explosions
called "gamma ray bursters," which may be the most violent
events in the universe. In 1987, the nearest supernova in 400
years exploded in a nearby galaxy, and at almost the same
moment that the supernova appeared as a dot of light visible
from the Southern Hemisphere, a neutrino detector in Ohio and
the Kamioka observatory in Japan picked up a strong neutrino
pulse.
"Sweden is threatening to withdraw from CERN for financial
reasons," he said, "and that could have a ripple effect
reducing the financial commitment of other European nations to
the coalition."
CERN, the acronym for Europe's high-energy-physics consortium, is
building what will be the world's most powerful accelerator,
the Large Hadron Collider, in a circular tunnel near
Geneva. Congress canceled an even larger accelerator that had
been under construction in Texas, but, with American
scientists still hoping to work at the cutting edge of
particle research, the United States has become a partner in
building the European collider.
Major reductions in support of CERN by European nations could
delay the new accelerator and other large programs, including
those designed to explore the question of neutrino
oscillations and mass. One such experiment would direct an
intense beam of neutrinos from one of the CERN accelerators
near Geneva through the ground about 450 miles to a neutrino
detector inside a vehicular tunnel under the Gran Sasso
Mountain in northern Italy. The idea is to see whether any
neutrinos change type during their long trip through the
earth's crust.
"Sometimes the accidents of politics and economics help
science," said Dr. Barry Barish of the California Institute of
Technology, who uses a detector in the Gran Sasso tunnel. "The
tunnel was built because local politicians persuaded the
government to appropriate a large sum for infrastructure, and
there was a problem finding something to spend it on. The
tunnel proved to be a boon for physicists who needed the
mountain above it to shield their experiments from unwanted
cosmic rays."
American members of the Super-Kamiokande team said they planned to
send a letter to the Japanese government pleading for steady
support of the observatory.
"American scientists greatly benefited from the Japanese
government's generosity," Stone said. "Japan paid for most of
the $100 million construction cost of Super-Kamiokande, and
the United States put up less than 10 percent, and yet
American physicists make up half the research force. We hope
the Japanese government will allow uninterrupted operation of
this great scientific instrument."