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The Global Calorimeter Trigger (GCT) is a device which uses data from the CMS calorimeters to search for jets, produce isolated and non-isolated electron lists and compute all the transverse and missing transverse energy sums used for the Level-1 trigger decision (L1A). GCT performs these functions by receiving and processing the data from the Regi...
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... 1 st stage of the current method ( fig. 4) is to create 2x3 mini-clusters, when the central cell is larger than neighbouring cells. When a central cell is larger than or equal to neighbouring cells the situation is more complicated (e.g. a jet divided equally between two cells). In this scenario a clustered jet should still be created. The equality statements between cells are ...
Citations
... Jet candidates are identified using a 3 × 3 sliding window of trigger regions (equivalent to 12 × 12 trigger towers, or 1.05 × 1.05 in η × φ). The jet-finder algorithm is described in detail in Ref. [12]. After jets are found, LUTs are used to apply a programmable η-dependent jet energy scale correction. ...
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam eventsduring data-taking runs in 2008, and to estimate the level of detector noise. This pa-per describes the trigger components used, the algorithms that were executed, andthe trigger synchronisation. Using data from extended cosmic ray runs, the muon,electron/photon, and jet triggers have been validated, and their performance evalu-ated. Efficiencies were found to be high, resolutions were found to be good, and ratesas expected Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams.
... Jet candidates are identified using a 3 × 3 sliding window of trigger regions (equivalent to 12 × 12 trigger towers, or 1.05 × 1.05 in η × φ). The jet-finder algorithm is described in detail in Ref. [12]. After jets are found, LUTs are used to apply a programmable η-dependent jet energy scale correction. ...
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam eventsduring data-taking runs in 2008, and to estimate the level of detector noise. This pa-per describes the trigger components used, the algorithms that were executed, andthe trigger synchronisation. Using data from extended cosmic ray runs, the muon,electron/photon, and jet triggers have been validated, and their performance evalu-ated. Efficiencies were found to be high, resolutions were found to be good, and ratesas expected
Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams. Available from: https://www.researchgate.net/publication/280810444_Performance_of_the_CMS_Level-1_trigger_during_commissioning_with_cosmic_ray_muons_and_LHC_beams [accessed Dec 29, 2015].
... Jet candidates are identified using a 3 × 3 sliding window of trigger regions (equivalent to 12 × 12 trigger towers, or 1.05 × 1.05 in η × φ). The jet-finder algorithm is described in detail in Ref. [12]. After jets are found, LUTs are used to apply a programmable η-dependent jet energy scale correction. ...
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam
events during data-taking runs in 2008, and to estimate the level of detector
noise. This paper describes the trigger components used, the algorithms that
were executed, and the trigger synchronisation. Using data from extended cosmic
ray runs, the muon, electron/photon, and jet triggers have been validated, and
their performance evaluated. Efficiencies were found to be high, resolutions
were found to be good, and rates as expected.
... Jet candidates are identified using a 3 × 3 sliding window of trigger regions (equivalent to 12 × 12 trigger towers, or 1.05 × 1.05 in η × φ ). The jet-finder algorithm is described in detail in ref. [12]. After jets are found, LUTs are used to apply a programmable η-dependent jet energy scale correction. ...
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.
... Jet candidates are identified using a 3 × 3 sliding window of trigger regions (equivalent to 12 × 12 trigger towers, or 1.05 × 1.05 in η × φ ). The jet-finder algorithm is described in detail in ref. [12]. After jets are found, LUTs are used to apply a programmable η-dependent jet energy scale correction. ...
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.
... The latter can require data flows of a similar magnitude to the incoming data volume depending on the clustering method used. The clusters, defined as the sum of 3x3 cells, are located using a new method [5]. It requires substantially less data sharing than the sliding window method. ...
The CMS Global Calorimeter Trigger (GCT) is the device within the Level-1 CMS calorimeter trigger system which is assigned the tasks of finding and sorting forward, central and tau-jet candidates, sorting isolated and non-isolated electron candidates and reading out all of the calorimeter trigger data. The GCT system has been installed and commissioned in the CMS underground cavern. A sophisticated software package has been developed for controlling and configuring the GCT hardware and monitoring the GCT status. Over the past two years the GCT system has undergone detailed testing and its performance is well understood. The GCT design provides for buffers at the inputs to the GCT which have been used to inject energy depositions corresponding to electrons and jets and test the GCT functionality by comparing the GCT output with that of simulation. Monte Carlo events simulating the decay of Higgs particles and other processes have been used to validate the performance of the GCT. The GCT has also been commissioned with the other components of the Level-1 trigger chain in cosmicray muon runs. Results from these studies are presented.
This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, τ lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described.
Compact Muon Solenoid at LHC;
The CMS Level-1 trigger was used to select cosmic ray muons and LHC beam events during data-taking runs in 2008, and to estimate the level of detector noise. This paper describes the trigger components used, the algorithms that were executed, and the trigger synchronisation. Using data from extended cosmic ray runs, the muon, electron/photon, and jet triggers have been validated, and their performance evaluated. Efficiencies were found to be high, resolutions were found to be good, and rates as expected.
