Detector at the asymmetric electron positron collider KEKB at K

Accelerated electrons and positron have reached the main ring of the SuperKEKB accelerator

February 2016

SuperKEKB, a super B factory accelerator to produce a huge number of B mesons, is being prepared for operation at KEK, an accelerator research center in Tsukuba, Japan. Studies of B mesons have helped us to understand the nature of CP violation, the difference between matter and anti-matter - here comes a movie on how this was possible,, and they also offer a unique window into the unknown world of New Physics, phenomena that are beyond our current understanding of elementary particles and their interactions.

In the SuperKEKB accelerator, electrons and positrons first have to be produced and accelerated to their full energy, after which they are led by electric and magnetic fields through vacuum pipes to enter the main ring of the accelerator. On Feb 1, 2016, SuperKEKB physicists have for the first time succeeded to accelerate and transport electrons and positrons to the 3 km long main ring. Here you can watch in a video how they are hitting a screen at the entry to the main ring

While the SuperKEKB accelerator is being prepared for operation, a new experiment for detecting B mesons is being constructed at the place where electrons and positrons collide. The experiment is called Belle II. You can find recent news from the Belle II experiment at A web page on the recent progress in accelerator commissioning is available at (at the moment in Japanese only, English version in preparation).