NEWS | FEATURES
26 SEPTEMBER 2014 • VOL 345 ISSUE 6204 1555 SCIENCE
It takes a big snare to catch a subatomic ghost. The newly completed NOνA neutrino detector is the size of a ware- house—five stories tall and more than three times that long—and consists of 896 planes of extruded plastic tubes filled with 10 million liters of min- eral oil. “This is the world’s largest free-standing plastic structure,” says
Richard Tesarek, a physicist at Fermi National Accelerator Laboratory (Fermilab), 810
kilometers away in Batavia, Illinois, which
will fire a beam of the elusive, almost massless particles into the detector. Tesarek says
he’s applying to Guinness World Records for
official recognition of the size claim.
NOνA—short for NuMI (itself an acronym)
Off-Axis Electron Neutrino Appearance
experiment—has a ghostly feeling. It sits in
the middle of nowhere, an hour south of
International Falls, population 6357, in
a building carved into the pink granite of
the Canadian Shield and surrounded by
kilometers of birch and red and white pine.
Aside from the whir of cooling fans, the
place is quiet. There isn’t even a barrier or
alarm to keep you from wandering into the
neutrino beam. (Neutrinos just go through
you harmlessly.) Still, for the next several
years NOνA will be the new center of action
in neutrino physics, perhaps the hottest
area of particle physics.
At first blush, NOνA’s prospects for
making major discoveries might seem dim.
The experiment is 2 or 3 years late coming
online, having barely survived a budget
cut 6 years ago. A neutrino experiment in
China beat it to the measurement that had
been NOνA’s primary goal. And NOνA has
been overshadowed by Fermilab’s efforts to
launch an even bigger neutrino experiment
proposed for the next decade.
But fate isn’t always cruel. As the
204 members of the NOνA team finish the
14,000-tonne, $278 million detector, they
find themselves with an excellent shot at
taking the next big step in the global quest
to decipher neutrinos, perhaps the most
mysterious of the fundamental particles.
NOνA could nail down which of the three
related kinds of neutrinos is the heaviest and
which is lightest. That seemingly esoteric
ranking bears on some of the biggest issues
in physics, such as why the universe contains
so much matter and so little antimatter.
“To me, NOνA has great potential,”
says Chang Kee Jung, a physicist at Stony
Brook University in New York and an
international spokesman for T2K, a similar
experiment in Japan that is NOνA’s direct
Despite years of delay, Fermilab’s massive new experiment has
a chance to take the next big step in neutrino physics
By Adrian Cho,
in Ash River, Minnesota
Workers ease one of NOνA’s
huge modules into place, lined
up like slices of bread in a loaf.
NOνA’s shining moment