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40 MHz Pipeline, Latency < 3.2 µsCalorimeter TriggerHFHCAL ECALRegionalCalorimeterTriggerGlobalCalorimeterTriggerMIP+ISO bitse, J, E T, H T, E Tm, H tm,N J, HFmax. 100 kHzL1 AcceptRPCPatternComparatorTriggerGlobal Trigger4+4 µMuon TriggerCSCLocalCSC TriggerCSC TrackFinder4 µGlobal Muon TriggerDTLocalDT TriggerDT TrackFinder4 µ4 µ (with MIP/ISO bits)External conditionsTechnical triggersTrigger SupervisorFigure 4.1: Overview of the Level-1 Trigger subsystems [21].Figure 4.2: Layout of calorimeter trigger towers in η [22].37
voltage information and 2 bits specifiying the gain) for every 25 ns period. For theTrigger Primitive Generation (TPG), a sliding window of ten such samples aroundthe current bunch crossing is considered. The signals from 25 crystals are linearizedand summed to five strip sums before undergoing filtering and time deconvolution tosuppress noise and identify the originating bunch crossing. These strip sums are usedto provide a fine-grain veto bit on the result when the shower profile is not sufficientlyconcentrated in one strip to be compatible with an electron or photon. The sum of thefive strip energies and the fine-grain veto bit are forwarded to a trigger concentratorwhich serializes inputs from a number of trigger towers and sends them to the RegionalCalorimeter Trigger (RCT).4.1.2 HCAL Trigger Primitive GenerationHCAL TPG is similar in principle to the process for the ECAL. The output signalsfrom photodiodes are digitized to a pseudo-floating point format (5 bits of significantdigits and 2 bits of range). An intermediate processor linearizes these values, providesbunch crossing identification and sums the appropriate inputs for a trigger tower. Thefine-grain veto bit of the ECAL TPG is replaced by the minimum ionizing particle(MIP) bit which indicates that the energy deposit is compatible with the passage of amuon. The output to the RCT happens in the same format as for the ECAL.4.1.3 Regional Calorimeter TriggerThe Regional Calorimeter Trigger (RCT) consists of 19 electronics crates in the CMScounting room. 18 of these crates receive the E T values from the trigger towers in bothHCAL and ECAL, each crate covering one half of the detector in z and 40 ◦ in φ. Eachof these identifies the four highest-ranking isolated and non-isolated electron or photoncandidates in its region and sends them to the global calorimeter trigger. In addition,it coarse-grains the E T sums over 4 × 4 trigger tower regions, assigning MIP (if oneof the HCAL trigger towers produced a MIP bit), quiet (if the energy sum is below athreshold value) and τ veto (if the activity in the 4 × 4 region is not compatible witha τ jet) bits to each region. These are forwarded to the Global Calorimeter Trigger(GCT). The HF trigger regions are forwarded to the GCT without processing.4.1.4 Global Calorimeter TriggerThe Global Calorimeter Trigger (GCT) receives the e/γ information from the RCT andsorts them in two Leaf Cards. A Concentrator Card receives data from the two LeafCards and performs the final sorting. Only the overall four highest-ranked candidatesout of 36 regional candidates are selected and forwarded to the GT for each of theparticle categories output by the RCT. The calorimeter trigger also looks for clustersin the E T sums provided by the RCT and produces jet candidates from these. The fourcandidates with highest E T for forward jets (from high-|η| regions), τ jets (without aτ veto bit in their region) and central jets each are forwarded to the global trigger.38
Page 5 and 6: 3.2.10 CMS Online Software . . . .
Page 7 and 8: factor. The selected events are the
Page 9: Figure 2.1: Expected dijet mass spe
Page 12 and 13: Figure 2.3: Left: Dilepton mass dis
Page 14 and 15: W −Z, γZ, γZ, γW +Z, γFigure
Page 16 and 17: ggHVHg(a)g(b)q¯q¯qHHV ∗q(c)qq(d
Page 18: Events per 4 GeV bin450400350300250
Page 21 and 22: 3 Experimental Setup3.1 Large Hadro
Page 23 and 24: 8.3 T. Such high fields were not ac
Page 26 and 27: luminosity) and limited storage ban
Page 28 and 29: Figure 3.4: Layout of the CMS pixel
Page 30 and 31: Figure 3.6: Transverse section illu
Page 32 and 33: Figure 3.8: HCAL jet energy resolut
Page 34 and 35: staggered by a half-cell each. A dr
Page 36 and 37: acceptance signal is distributed to
Page 38 and 39: Figure 3.11: Generic state machine
Page 40 and 41: Figure 3.12: Components of a CMSSW
Page 44 and 45: In addition, the GCT calculates a n
Page 46 and 47: Figure 4.4: η boundary between the
Page 48 and 49: Figure 4.5: Organization of the DTT
Page 50 and 51: Condition Type Subtype Parametersmu
Page 52 and 53: oards making up the GT and sends th
Page 54 and 55: • ESProducers: components that re
Page 56 and 57: 5 Pattern Testing for the Level-1 G
Page 58 and 59: the required processing is mostly c
Page 60 and 61: RAW DIGIL1GctJetCandCollection (for
Page 62 and 63: information about an event that is
Page 64 and 65: muons 2 or two PSB channels (named
Page 66 and 67: 5.3 Software ImplementationThe exec
Page 68 and 69: tsframework::CellOperationTestOpera
Page 70 and 71: system. Each subsystem maintains it
Page 72 and 73: Test Execution PanelThe test execut
Page 74 and 75: Figure 5.10: The pattern test resul
Page 76 and 77: FEDRawDataCollectionL1GlobalTrigger
Page 78 and 79: Figure 6.3: Result of a Function Te
Page 80 and 81: Figure 6.6: Disagreements in e/γ a
Page 82 and 83: Figure 6.9: TestCell output from an
Page 84 and 85: Bibliography[1] Abraham Pais. Inwar
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