2,648 research outputs found
Performance of the LHCb High Level Trigger in 2012
The trigger system of the LHCb experiment is discussed in this paper and its
performance is evaluated on a dataset recorded during the 2012 run of the LHC.
The main purpose of the LHCb trigger system is to separate heavy flavour
signals from the light quark background. The trigger reduces the roughly 11MHz
of bunch-bunch crossings with inelastic collisions to a rate of 5kHz, which is
written to storage.Comment: Proceedings for the 20th International Conference on Computing in
High Energy and Nuclear Physics (CHEP
Monte Carlo Independent Lifetime Fitting at LHCb in Lifetime Biased Channels
Lifetime measurements at LHCb will help in detector calibration as well as providing constraints on lifetime differences in the system and other theoretical models. In order to exploit the full range of decays available in LHCb, it is important to have a method for fitting lifetimes in hadronic channels, which are biased by the impact parameter cuts in the trigger. We have investigated a Monte Carlo simulation independent method to take into account the trigger effects. The method is based on calculating event by event acceptance functions from the decay geometry and does not require any external input. This note presents current results with this method for both the full LHCb Monte Carlo for the channel and a toy Monte Carlo for the same channel, including a discussion of the expected statistical precision on lifetime measurements using this method once LHCb is operational
A Monte Carlo simulation free method of measuring lifetimes using event-by-event acceptance functions at LHCb
A set of innovative methods and tools for precision lifetime and lifetime-difference measurements in hadronic B decays at LHCb is presented. All methods are purely data-driven and Monte Carlo simulation independent, a particularly important feature if lifetime measurements are to be made in the early period of LHCb's data taking. The methods and tools are shown to work in detailed simulation studies, including both Toy and Full Monte Carlo simulation studies of possible systematic biases in the measurements
Waisda?: video labeling game
The Waisda? video labeling game is a crowsourcing tool to collect user-generated metadata for video clips. It follows the paradigm of games-with-a-purpose, where two or more users play against each other by entering tags that describe the content of the video. Players score points by entering the same tags as one of the other players. As a result each video that is played in the game is annotated with tags that are anchored to a time point in the video. Waisda? has been deployed in two projects with videos from Dutch broadcasters. With the open source version of Waisda? crowdsourcing of video annotation becomes available for any online video collection
- âŠ