600/fb Celebration

Just had the 600/fb party tonight. At a particle collider like KEKB, which produces the B mesons detected by the Belle experiment, the efficiency with which collisions occur is measured by “luminosity,” and depends on how many particles we can smash into a tiny area each second. The total amount of data recorded is called “integrated luminosity,” and is calculated by adding up the luminosity over the lifetime of the experiment.

This integrated luminosity is a direct measure of the number of collisions that have occurred, and is measured in units of /fb (inverse femto barns). For us, 1/fb of integrated luminosity will produce approximately one million B meson pairs, and takes about one day to accumulate. The more integrated luminosity we record, the more rare matter/antimatter decays we can see, and the better we can understand the difference between the behavior of matter and antimatter.

The original goal of KEKB was to produce 100/fb in 3 years, although due to a lot of improvements to the accelerator we’ve ended up taking six times that amount in just twice the time. Good work accelerator team.


(Above photo was taken from the KEKB page)