The KEK site is located close to the Mt. Tsukuba,
about 70 km from the both Narita-Tokyo airport
and central Tokyo.
This picture shows the 400 m long
electron and positron linac and the buildings above
the collider ring, whose circumference is about 3 km.
The KEK B factory experiment (Belle) started operation in 1999.
Using a large data sample that corresponds
to an integrated luminosity of ~0.8 ab-1,
or, 900 million B anti-B meson pairs, the Belle experiment has verified
the Kobayashi-Maskawa theory that explains CP violation
and quark mixing in the weak interaction. This experimental work
eventually led to a Nobel prize for Kobayashi and Maskawa in 2008.
Link to 2008 Physics Nobel prize page.
We are now preparing for the Super KEK B factory, a project that detects new phenomena that arise from physics beyond the standard model, such as Supersymmetry or extra dimensions, by using a much larger amount of data: 50 ab-1, or, 50 billion B anti-B meson pairs.
The Super KEK B factory also produces a huge number of charmed hadrons and tau leptons. This will allow for sensitive searches for CP violation in D meson mixing, which would be a "smoking gun" for new physics. Studies of tau decays, in particular searches for lepton number violation with an unprecedented sensitivity, will also provide one of the most stringent tests of the Standard Model of particle physics.
Such an ambitious experiment requires an electron-positron collider whose luminosity is 50 times larger than that of the present KEK B factory. It also requires a particle detector that records a few thousand physics events per second. Finally, the results of the new experiment may enable us to construct a new theoretical framework that explains not only the observed properties of quarks and leptons but also the laws of nature that lead to the almost complete dominance of matter over anti-matter in our universe.
This web site introduces you to this exciting
field of physics research.
New! You are invited to send any questions you might have to our experts.
This page is maintained by Hiroe Yamaguchi
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