Belle Is Back

Belle is now taking data again after the spring maintenance shutdown. The KEKB accelerator team have spent the last couple of days aligning and checking the condition of the beams, and they started collisions about 6PM yesterday.

The Belle event display can be seen live one the net here, or else it can be reached from the links in the bottom left corner of the Belle webpage.

The picture shows an end view of the detector. The electron and positron beams collide head on in the centre, and the charged particles that result from the collisions are captured as they spread out through the detector. A lot of the data we capture are Bhabha scattering events, where the positron and electron just scatter off each other and stop in the detector, like this:


But occasionally there is an interesting one where they annihilate and create new particles, like this one:


Usually we have a few troubles in the first week or so after we restart taking data, so it's normally a bad time to be on shift, but everything seems to be working well so far. Fingers crossed for the rest of the week.

(Updated photos.)