Status of CMS and the Austrian Contribution to the Trigger System

The CMS Collaboration 1809 Physicists and Engineers 31 Countries Number of Laboratories Belgium Austria Bulgaria Member States 58 USA CERN Finland Non-Member States 50 USA 36 France Total 144 Germany Russia Number of Scientists Greece Uzbekistan Hungary Member States 1010 Ukraine Italy Slovak Republic Non-Member States 448 Georgia UK USA 351 Belarus Poland Armenia Turkey Total 1809 India Spain Portugal Taiwan Korea China Estonia Pakistan Switzerland Cyprus Associated Institutes Number of Scientists Number of Laboratories 36 5 Croatia 1809 Physicists and Engineers 31 Countries 144 Institutions July, 26th, 2000 Claudia-Elisabeth Wulz

The CMS Detector The CMS detector is designed to analyze proton-proton and heavy-ion collisions at CERN’s Large Hadron Collider. Its diameter is 15 m, its length is 21.6 m and its weight is approximately 12500 tons. Claudia-Elisabeth Wulz

Assembly of First Magnet Wheel Claudia-Elisabeth Wulz

Site of the CMS experiment Claudia-Elisabeth Wulz

Muon Chamber Assembly Claudia-Elisabeth Wulz

CMS Main Physics Goals Standard Model Higgs (if not confirmed at LEP) Supersymmetric Higgses Other supersymmetric particles Claudia-Elisabeth Wulz

Principles of Triggering in CMS The purpose of the trigger system is the selection of all interesting events in the presence of an overwhelming background. CMS has a hierarchical trigger system, consisting of a First Level, a Second Level and several Higher Level Triggers. The First Level Trigger is a custom designed electronics system, the Higher Level Triggers are all commercially available processors. The First Level Trigger has to take a decision within 3.2 ms, determined by the size of the currently available analog pipeline memories for the tracker. At the LHC design luminosity of 1034 cm-2s-1 about 25 inelastic proton-proton collisions occur every 25 ns corresponding to an interaction rate of about 1 GHz. The First Level Trigger must reduce this rate to 100 kHz, the maximum tolerable input rate to the Second Level Trigger. Events can be written to mass-storage with a rate of 100 Hz. The First Level Trigger has to provide an accept/reject decision (L1A) for every bunch crossing. It therefore has to run dead-time free. Claudia-Elisabeth Wulz

CMS First Level Trigger Claudia-Elisabeth Wulz

CMS Global Trigger Global Trigger Environment For physics running the Global Trigger uses only input from the calorimeters and the muon system. The data used for triggering are relatively coarse. The high resolution data are used by the Higher Level Triggers. Special signals from all sub-systems may be used for calibration, synchronization and testing purposes (technical triggers). The TTC System is an optical distribution tree that is used for the transfer of the Level-1 Accept signal and timing information (LHC clock etc.) between the trigger and the detector front-ends. The Trigger Control System controls the delivery of L1A signals and issues bunch crossing zero and bunch counter reset commands. There is a facility to throttle the trigger rate in case of buffers approaching overflow conditions. The Event Manager controls the Higher Level Triggers and the data acquisition. Global Trigger Environment Claudia-Elisabeth Wulz

Typical Trigger Conditions Trigger Thresholds/GeV Examples of explorable physics channels 1 m 15 HSM, H, A, H±, W, W’, t, B-physics channels 2 m 5, 5 HSM, h, H, A, Z, Z’, V, , LQ, Bs0 -> 2m, , ’, ’’ m+e/g 5, 15 HSM, H, A, t, WW, WZ, Wg, , V m+jet(s) 5, 50 HSM, h, H, A, , LQ, t m+ETm 5, 100 t, , LQ, WW, WZ, Wg 1 e/g 20 HSM, h, H, A, W, W’, t, B-physics channels 2 e/g 15, 15 HSM, h, H, A, Z, Z’, WW, WZ, Wg, , LQ 2 jets 60, 60 QCD e/g+jet(s) 15, 60 HSM, h, H, A, , LQ, QCD (g +jets, W+jets) m+t 5, 20 HSM, H, A, e/g+t 15, 20 HSM, H, A, t+jets 15, 60 H± jets+ETm 60, 100 , H± Claudia-Elisabeth Wulz

Algorithm Logic Initial step: Particle and Delta Conditions The first are applied to a group of objects. The conditions are: ET or pT thresholds, h/f-windows, bit patterns for isolation, quality, charge, and spatial correlations (Dh, Df) between objects of the same type. Delta Conditions calculate spatial correlations between different objects. Particle Condition for 2 back-to-back isolated electrons Particle Condition for 2 back-to-back isolated opposite-sign muons with MIP bits set Claudia-Elisabeth Wulz

Algorithm Logic Next step: Actual algorithm calculations. Logical combinations (AND-OR) of objects are determined. Claudia-Elisabeth Wulz

Algorithm Logic Claudia-Elisabeth Wulz

Global Trigger Logic Hardware Claudia-Elisabeth Wulz

Implementation of First Level Trigger PSB (Pipeline Synchronizing Buffer) Input synchronization GTL (Global Trigger Logic) Logic calculation FDL (Final decision logic) L1A decision TIM Timing GTFE (Global Trigger Frontend) Readout Claudia-Elisabeth Wulz

PSB Prototype Claudia-Elisabeth Wulz

Conclusions and Outlook CMS construction (detector components and experimental area)    is well under way. First physics runs are expected in 2005/2006. Austria is responsible for crucial parts of the trigger system   (Global Trigger, Global Muon Trigger and Barrel Track Finder). All three contributions are well advanced. The design is   practically finished. Prototypes of the critical items either exist   (PSB) or are nearing completion (GTL). Claudia-Elisabeth Wulz