 |
| Stanford
Linear Accelerator Laboratory's
Asymmetric B-Factory |
All particles of matter have mirror
images called antimatter. The universe
prefers matter—antimatter is
created only in laboratories today—and
physicists are not sure why. The answer
may lie in differences in the ways
unstable particles of matter and antimatter
decay, or break down into more stable
particles. Physicists now have the
accelerators needed to test these
differences, thanks to Piermaria Oddone
of Lawrence Berkeley National Laboratory,
the father of the "B-factory" (so-named
because it makes particles containing
"bottom" or b quarks). In the late
1980s, Oddone suggested looking for
the matter/antimatter asymmetry with
a collider of electrons and positrons
(anti-electrons) using beams of unequal
energy, a radical approach at the
time. His proposal led to Stanford
Linear Accelerator Laboratory's Asymmetric
B-Factory, a collaboration of three
national laboratories that began operating
in 1999. Researchers use it to measure
the decay of B mesons, rare particles
that are a mix of matter and antimatter.
The asymmetric design allows particles
to move in a way that is conducive
to study and provides for high luminosity
(rate of particle collisions). In
2000, the first results were reported
of a breakdown in matter/antimatter
symmetry in B mesons.
Scientific Impact:
The collider design was unprecedented
and has achieved luminosities that
exceed the previous world record.
Operation of the Asymmetric B-Factory
promises to provide a stringent test
of the Standard Model, physicists'
current theory of matter and the forces
of nature.
Social Impact: These
studies will help humans better understand
the origins of the universe and why
matter, including the Earth and its
inhabitants, exists. (A preference
for antimatter in the universe would
have annihilated all matter.) In addition,
the collider design project produced
an electronics technology spin-off,
a new methodology for circuit board
design and fabrication.
Reference: P. Oddone,
Proceedings of the UCLA Workshop
on Linear Collider B B-Factory Conceptual
Design, ed. by D. Stork (1987).
URL: http://www2.slac.stanford.edu/vvc/experiments/bfactory.html
http://www.lbl.gov/Science-Articles/Research-Review/Highlights/2000/stories/physics/yearone2.html
Technical Contact:
Pier Oddone, pjoddone@lbl.gov
Jonathan Dorfan, jonathan@slac.stanford.edu
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of High Energy and Nuclear
Physics |
