KEKB was a particle accelerator used in the Belle experiment to study CP violation. KEKB was located at the KEK in Tsukuba, Ibaraki Prefecture, Japan. It has been superseded by its upgrade, the SuperKEKB accelerator. The SuperKEKB is a luminosity upgrade of KEKB. SuperKEKB had its first particle collisions in 2018. The SuperKEKB accelerator produces particle beams for the Belle II experiment, which is an upgrade of the Belle experiment. The Belle experiments studied b-quark hadrons to research CP violation.
KEKB was called a B-factory for its copious production of B-mesons which provide a golden mode to study and measure the CP violation due to its property of decaying into other lighter mesons. KEKB was basically an asymmetric electron–positron collider, with electrons having the energy of 8 GeV and positrons having the energy of 3.5 GeV, giving 10.58 GeV centre-of-mass energy, which is equal to the mass of the Υ meson.
Wikipedia https://en.wikipedia.org/wiki/KEKB_(accelerator)
Official Website http://www-acc.kek.jp/KEKB/
Address Japan
Coordinates 36°9'16.574" N 140°4'18.51" E