The Latest from LHCb

This month the LHCb Collaboration has observed the first Cherenkov rings from the RICH1 detector. These rings were emitted by cosmic particles passing through the detector.

Cherenkov radiation occurs when a charged particle passes through a medium faster than the speed of light. As it travels, the particle emits photons along a cone. This cone is measured and, along with a measurement of momentum, is used to identify the particle.

There are two types of radiators in RICH1, the first gaseous and the other made from aerogel. Both rings seen on the picture are from the same particle passing through the two different radiators.

This is the fist time that the RICH detector has seen a particle as it will see them when the LHC re-starts.

It has also been a time for the experiment to begin commissioning. After network upgrades, LHCb held a commissioning week, an opportunity for physicists working on all the different detectors within LHCb to test the system.

During this week the LHCb team managed full detector readout at almost 1MHz, which is impressive. Data packets were sent at 100kHz through to the LHCb computer farm, and each sub-detector was tested to ensure the system could handle data at this rate.

The test turned out to be very useful since some data loss at an extremely low rate could be detected. The source of the problem has been identified and referred back to the manufacturer.

With this successful high rate test LHCb has demonstrated once again that the experiment is ready to take data when the LHC re-starts. The LHCb team is also looking forward to a dedicated beam dump (TED) run in October, when the final tuning of the Silicon Trackers and VELO under operational conditions will take place.

LHCb Collaboration