New Neutrino Experiment at Fermilab Goes Live
Batavia, Ill.-Scientists of the Booster Neutrino Experiment collaboration
announced this week that a new detector at the U.S. Department of Energy’s
Fermi National Accelerator Laboratory has observed its first neutrino
events. The BooNE scientists identified neutrinos that created ring-shaped
flashes of light inside a 250,000-gallon detector filled with mineral oil.
The major goal of the MiniBooNE experiment, the first phase of the BooNE
project, is either to confirm or refute startling experimental results
reported by a group of scientists at the Los Alamos National Laboratory. In
1995, the Liquid Scintillator Neutrino Detector collaboration stunned the
particle physics community when it reported a few instances in which the
antiparticle of a neutrino had presumably transformed into a different type
of antineutrino, a process called neutrino oscillation.
“Today, there exist three very different independent experimental results
that indicate neutrino oscillations,” said Janet Conrad, a physics professor
at Columbia University and cospokesperson of the BooNE collaboration.
“Confirming the LSND result would suggest the existence of an additional
kind of neutrino beyond the three known types. It would require physicists
to rewrite a large part of the theoretical framework called the Standard
Model.”
Over the next two years, the BooNE collaboration will collect and analyze
approximately one million particle events to study the quantum behavior of
neutrinos. Although these ghost-like particles are among the most abundant
particles in the entire universe, little is known about their role in
nature.
“It is an exciting time for neutrino physics,” said Department of Energy
Office of Science Director Raymond Orbach. “In the past few years
experiments around the world have made extraordinary neutrino observations,
shattering the long-standing view that neutrinos have no mass. The MiniBooNE
experiment has the potential for advancing the revolution of our
understanding of the building blocks of matter.”
The MiniBooNE experiment, under construction from October 1999 to May 2002,
relies on an intense beam of muon neutrinos created by the Booster
accelerator at Fermilab. About 1,500 feet from its production point, the
neutrino beam traverses a 40-foot-diameter tank filled with ultraclean
mineral oil. The tank’s interior is lined with 1,520 light-sensitive
devices, called photomultiplier tubes, that record tiny flashes of light
produced by neutrinos colliding with carbon nuclei inside the oil.
“We will operate the experiment 24 hours a day, seven days a week,” said
Bill Louis, a Los Alamos scientist and cospokesperson of the BooNE
collaboration. “We will be looking for oscillations of muon neutrinos into
electron neutrinos. If nature behaves as LSND suggests, our detector will
collect about one thousand electron neutrino events over the next two years.
If not, we won’t see any electron neutrinos. Either way, we’ll get a
definite answer.”
The BooNE collaboration comprises 66 scientists from 13 institutions from
across the United States. The 19-million-dollar MiniBooNE experiment has
received funding both from DOE’s Office of Science and the National Science
Foundation.
“In addition to the importance of the science, MiniBooNE is an example of a
successful partnership among federal agencies, universities and national
laboratories,” said Marvin Goldberg of the National Science Foundation. “The
project has also set new standards for education and public outreach in the
field of high-energy physics. The small scale of the project allows
undergraduate and graduate students to participate fully in all of the
experimental components.”
Fermilab is a U.S. Department of Energy national laboratory, operated under
contract by Universities Research Association, Inc.
