VT College of Science Quarterly August 2014 Vol. 1 No. 1 | Page 4

The Belle
Experiments
Born in the basement of Robeson Hall, Japanbased accelerator gets upgraded, continues to
yield discoveries including four-quark particle
To answer the questions of how the universe works, physicists must
solve a series of problems, such as how to best collect the data allowing
them to discover and learn about the building blocks of our world.
To help solve the problem of how to collect data to study matter and
anti-matter, faculty and students at Virginia Tech built some novel
equipment in the basement of Robeson Hall in the late 1990s that
continues to have a definitive impact on how physicists understand the
universe. This equipment forms a key component of the Belle detector,
a subatomic physics experiment located at the High Energy Accelerator
Research Organization (KEK) Laboratory in Tsukuba, Japan.
The Belle detector, built in segments and assembled in Japan, has
more than 400 collaborators who have been making discoveries ever
since, including the latest, a new state of matter consisting of a fourquark particle with an electrical charge.
There are six quarks – the elementary building blocks of matter – the
Up, Down, Strange, Charm, Bottom, and Top quarks (and their anti-matter counterparts). Typically, researchers have found three-quark states
like the proton or neutron but in June, the first four-quark state with a
non-zero electrical charge was discovered.
“A team from China within the Belle collaboration found this new
state of matter,” said Leo Piilonen, the William E. Hassinger Jr. Senior

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College of Science Quarterly

From Left: Anthony Lanzillotta of Odenton, Md., a sophomore majoring in physics with a minor in c
Kevin Strasel, of Arlington, Va., a senior physics major, uses a computer program to test a rack of ligh
about 100 in a frame and tested again. Brennon Stoval of Prince George, Va., a senior physics major
ability of the cable to reflect light properly. Several thousand bars were necessary for the project to

Faculty Fellow in Physics and chair of the department at Virginia Tech.
“We weren’t looking for it, it just popped up in the data, and it’s one of
the more intriguing results from the Belle experiment.” This new particle
was discovered at the same time by an independent experiment named
BESIII and the results from both experiments were published at the
same time in Physical Review Letters.
Since it started taking data in 1999, the Belle experiment has led to
the Nobel Prize in Physics in 2008 for Makoto Kobayashi and Toshihide
Maskawa, and a host of other discoveries while studying the behavior
of matter and anti-matter.
The newest four-quark particle consists of a quartet of Charm/antiCharm quarks and Up/anti-Down quarks, which provide its electrical
charge. Scientists don’t capture it and see it so much as measure it
indirectly through the byproducts of its disintegration, as it exists for a
fraction of a nano-second.