Level 1 Trigger system design specifications 1MHz Tevatron Collisions Level 2 Level 3 Tape 10kHz1kHz20-50Hz Time budget for Level3 i/o, event building, filtering  100 nodes * s = 0.1 s

Level 1 Framework Two views of the Framework Racks The L1 trigger logic is all performed on a VME card

Level 1 Framework 1.The L1 Trigger associated with each detector examines every event. Decisions are reported as trigger terms (AND OR network) to the Framework (L1FW), which support 128 L1 trigger bits (0 or 1) 2.Each “L1 trigger bit” is programmed to require a specific combination of trigger terms. A series of FPGAs (field programmable gates arrays) examine the list of terms collected from CFT,CPS,CAL, MUON to determine If a L1 bit has been satisfied. 3. When L1FW issues an accept, the event data is digitized and moved into16-event buffers to await a L2 trigger decision

Operation and General Architecture: accept 10 kHz event rate ~~~ 1kHz correlating info on found objects across sub-detectors Two processor stages 1. “worker” preprocessors prepare Level1 data (50  s decision time) (CAL, Muon, tracking: CFT & CPS) 2. “global” processors combine L1 trigger objects from the detectors. (75us decision time) Level Two highways operate at 320Mbytes/sec to provide the decision within 75  s.

Individual preprocessors CAL preprocessor Muons preprocessor Tracking preprocessor building the jets and electron candidates; calculating their energy testing jets for shape testing transverse energy requirement Improving the Mouns identification by repeating the Level 1 calculation with more resolution and more information Using the parallel architecture to provide an algorithm with execute time independent of detector hits CFT : assembling PT or azimuthally order a list of trigger tracks before transmission to the global processor. CPS: computing azimuth and rapidity of electrons candidate

L2 Global processor input L2 fiber tracker tracks <2 L2 central preshower clusters in the CPS detector <1.2 L2 forward preshowerclusters in the FPS detector 1.4~~2.5 L2 calorimeter (EM)electromagnetic clusters L2 calorimeter (JET) jets L2 calorimeter (MET)missing transverse energy L2 muon (central)muons found in central region <1 L2 muon (forward) muons found in forward region 1~~2

Trigger & Data Acquisition Systems Detector L1 trigger L2 trigger L3 trigger tape 1.7 MHz bunch crossing rate 10 kHz L1 accept 1000 Hz L2 accept 50 Hz L3 accept Jets Muon electron tracking Missing E T, sum-E T Silicon tracking CPU’s Jet finding Full event reconstruction Data Collection: Trigger & DAQ (Online)Data Reconstruction & Analyses (Offline) Re-process data using more accurate calibrations Data storage Perform analyses

Current Rate Limitations 1400 Hz Chosen to limit front end busy rates ( <5% ) 800 Hz system readout instability above 850 Hz 50 Hz above 35E30 60 Hz below 35E30, where additional rate is from B triggers Forced by consideration of reconstruction limitations

W  ee e You have all been working through an exercise of making the W transverse mass plot from data selected with W  e e candidates data that certainly came from single electron triggers…

L3 Trigger Name L1 TriggerL2TriggerL3 FilterPrescale E1_SHT20 E2_SHT20 E3_SHT20 CEM(1,11) CEM(2,6) CEM(1,9) CEM(2,3) none1 EM object with Et>20 GeV and tight shower shape requirements with EM fraction of cluster > E1_SH30 E2_SH30 E3_SH30 share same L1 bits none1 EM object with Et>30 GeV loose shower shape requirements with EM fraction of cluster > E1_SHT15_M15 E2_SHT15_M15 E3_SHT15_M15 share same L1 bits none1 EM object with Et>15 GeV and tight shower shape requirements EM fraction of cluster is > 0.9 missing pT > 15 GeV NADA applied at L3 missing pT calculated relative to vertex reconstructed using L3 tracks with pT>3 Ge V 1 38 “flavors” of “single electrons” triggered on

L3 Trigger Name L1 TriggerL2TriggerL3 FilterPrescale EM_HI_EMFR8 CEM(1,10)1 EM object, Et> 12 GeV 1 EM object with Et>40 GeV and EM fraction> EM_HI shares same L1 bit 1 EM object, Et> 12 GeV 1 EM object with Et>30 GeV and EM fraction> EM_HI_SH shares same L1 bit 1 EM object, Et> 12 GeV 1 EM object with Et>20 GeV loose shower shape cuts and EM fraction> EM_HI_SH_TR shares same L1 bit 1 EM object, Et> 12 GeV 1 EM object with Et>12 GeV loose shower shape cuts EM fraction>0.9, and a track with pT>12 GeV 1-3 EM_HI_TR shares same L1 bit 1 EM object, Et> 12 GeV 1 track with pT>25 GeV1-3

W  ee e   ττ τ d u

L3 Trigger NameL1 TriggerL2TriggerL3 FilterPrescale mu1ptxatxx_ncumu1ptxatxx (all region scint. trigger) Nonenone MT10W_L2M5_TRK10mu1ptxwtxx TTK(1,10) (CFT track pT>10 GeV) 1 medium muon with pT>5 GeV L3 track with pT>10 GeV 1 MUW_W_L2M3_TRK10mu1ptxwtlx (wide region scint. trigger w/ loose wire req’d) 1 medium muon with pT>3 GeV L3 track with pT>10 GeV 1 MU_W_L2M3_TRK10mu1ptxwtxx (wide region scintillator trgr) 1 medium muon with pT>3 GeV L3 track with pT>10 GeV 1-3 MUZ_A_L2M3_TRK10mu1ptxatxx_fz (all region scintillator trigr fast Z coinc) 1 medium Muon with pT>3 GeV L3 track with pT>10 GeV 1-5 MU_A_L2M3_TRK10mu1ptxatxx (all region scintillator trgr) 1 medium muon with pT>3 GeV L3 track with pT>10 GeV 1-15 ~20 flavors of single muon triggers

October 2004 Jim Linnemann (Michigan State University) 7 years as convenor of the RUN I Level 2 trigger 7 years as convenor of the RUN II Level 2 trigger Daniel Claes (University of Nebraska) 5 years working on of the RUN I Level 2 trigger (under Jim) 7 years as convenor of the RUN II Level 3 trigger were tapped to co-convene the Level 2 Algorithms group charged with finding new (and new combinations of) Level 2 triggers to provide needed rejection The NEXT bottle neck is predicted to be maxing out Level 3 CPU time With increased luminosity, not only will higher rates will be pushing through the system, but MORE COMPLICATED EVENTS putting the burden the L3 processing farm.

DØ Trigger Simulator Manual Getting Started ( The Cookbook Method ) The first thing you need to run TrigSim is a set of events to run it over. These can be either Monte Carlo (MC) generated or data taken online. The only requirement is that it be in "raw" form (i.e..raw ). If you do not have a.raw data file, link to a file TrigSim managers use for debugging (the path is in the example below). The debug.raw file has 500 MC t-tbar events created with MC version p Choose a production release number to use. In p14 versions and earlier TrigSim runs as a single executable. In p15 (t ) and later, it runs as two executables: one which does the trigger simulation and a second which creates the rootuple output. Let's start with a newer version, say p Get your run environment setup by typing: setup D0RunII p setup d0tools -t Create a text file containing the path & file name(s) of your.raw file(s), one file per line. If you wish to use our MC sample, copy the platform-appropriate example filelist: d0mino_default_mc_filelist.txt or clued0_default_mc_filelist.txt. d0mino_default_mc_filelist.txtclued0_default_mc_filelist.txt The simulation part of TrigSim requires at least two arguements: what file(s) to run on, and what format the events are. The valid format choices are mc and data. In this example, we will use mc. To run TrigSim, just type: runD0TrigSim -filelist=default_mc_filelist.txt -format=mc The outputs from this command will appear in a newly created directory whose name starts with D0TrigSim_x-. TrigSim Documentation link from

Beside the online documentation and tutorials our Fermilab postdoc Angela Bellavance ( who maintains those pages and serves as convenor of the TrigSim effort ) will prove an excellent resource This makes the project a very natural one for Nebraska students!