cms - trigger recfa-meeting leopold-franzens-universität innsbruck, 26 march 2004 presented by...

CMS - TriggerCMS - Trigger

RECFA-MeetingLeopold-Franzens-Universität

Innsbruck, 26 March 2004

Presented by

Claudia-Elisabeth WulzClaudia-Elisabeth WulzInstitute for High Energy Physics, Vienna

http://wwwhephy.oeaw.ac.at/p3w/cms/trigger

C. - E. Wulz 2 RECFA, March 2004

CMS Detector at the CERN Large Hadron Collider


Cross sections for different processes vary by many orders of magnitude

• inelastic: 109 Hz• W l: 100 Hz• tt: 10 Hz• Higgs (100 GeV): 0.1 Hz• Higgs (600 GeV): 0.01 Hz

Required selectivity 1 : 10 10 - 11

TriggerTrigger

-

Cross Sections and Rates


Only calorimeters and muon system involvedOnly calorimeters and muon system involvedReason: no complex pattern recognition as in tracker required (appr. 1000 tracks at 1034 cm-2s-1 luminosity), lower data volumeTrigger is based on:Trigger is based on:Cluster search in the calorimetersTrack search in muon system

CMS Level-1 Trigger


Level-1 Trigger and Institute Responsibility4

0 M

Hz

pip

elin

e,

late

ncy

< 3

.2

s

HFHF HCALHCAL ECALECAL RPCRPC CSCCSC DTDT

PatternPatternComparatorComparator

Trigger Trigger

RegionalRegionalCalorimeterCalorimeter

TriggerTrigger

4 4 4 4 4+4 4+4

4 4 (with MIP/ISO bits)(with MIP/ISO bits)

MIP+MIP+ISO bitsISO bits

e, J, Ee, J, ETT, H, HTT, E, ETTmissmiss

Calorimeter TriggerCalorimeter Trigger Muon TriggerMuon Trigger

Responsibility

of Vienna Institutemax. 100 kHz L1 Accept

Global TriggerGlobal Trigger

Global Muon TriggerGlobal Muon Trigger

GlobalGlobalCalorimeterCalorimeter

TriggerTrigger

Local Local DT TriggerDT Trigger

Local Local CSC TriggerCSC Trigger

DT TrackDT TrackFinderFinder

CSC TrackCSC TrackFinderFinder


System Overview

Global Trigger + Global Muon Trigger: 1 Rack

Drift Tube Track Finder: 3 Racks


Muon Trigger Detectors

Drift Tube Chambers and Cathode Strip Chambers are used for precision measurements and for triggering.

Resistive Plate Chambers (RPC’s) are dedicated trigger chambers.


Barrel Muon Chambers

Mounting of a Drift Tube Chamber into the iron yoke


Endcap Muon Chambers

Cathode Strip Chambers on endcap iron yoke


Transport of the First Magnet Coil Module

A good muon trigger needs a high magnetic field!


Regional Muon Trigger

Track Finder Processor• Pipeline logic running at 40MHz (LHC bunch crossing frequency)• Implemented in programmable logic devices• Based on extrapolation and pattern matching methods

Drift Tubes(CSC’s similar)


Drift Tube Trigger Track Finder

The trigger is based on correlating compatible track segments pointing The trigger is based on correlating compatible track segments pointing to the vertex. At most four detector planes are used in to the vertex. At most four detector planes are used in azimuth (transverse to the magnetic field direction) and three in (transverse to the magnetic field direction) and three in pseudorapidity (along the beam axis). If possible, track candidates found in both (along the beam axis). If possible, track candidates found in both projections are then matched.projections are then matched.

Eta Track Finder

Track segment (with direction of extrapolation)

Phi Track Finder(Sector Processor)


Muon Trigger PrototypesSector Processor Timing Module

Eta Track Finder

Wedge Sorter (Bologna)

Trigger Crate


Global Muon Trigger

Output:Output:8 bit8 bit, 6 bit , 6 bit , 5 bit p, 5 bit pTT, ,

2 bits charge/synch, 3 bit 2 bits charge/synch, 3 bit quality,quality, MIP bit, Isolation bitMIP bit, Isolation bit

Output:Output:8 bit8 bit, 6 bit , 6 bit , 5 bit p, 5 bit pTT, ,

2 bits charge/synch, 3 bit 2 bits charge/synch, 3 bit quality,quality, MIP bit, Isolation bitMIP bit, Isolation bit

Inputs:Inputs:8 bit 8 bit , 6 bit , 6 bit , 5 bit p, 5 bit pTT, ,

2 bits charge, 3 bit quality,2 bits charge, 3 bit quality,1 bit halo/eta fine-coarse1 bit halo/eta fine-coarse

Inputs:Inputs:8 bit 8 bit , 6 bit , 6 bit , 5 bit p, 5 bit pTT, ,

2 bits charge, 3 bit quality,2 bits charge, 3 bit quality,1 bit halo/eta fine-coarse1 bit halo/eta fine-coarse

Best 4 Best 4

4 4 RPC RPC barrelbarrel

4 4 DT DT

4 4 CSC CSC

4 4 RPC RPC forw.forw.

252 MIP bits252 Quiet bits

DR/CSC/RPC: DR/CSC/RPC: combined in combined in Global Muon Trigger, Global Muon Trigger, isolation and MIP isolation and MIP information addedinformation added


Global Muon Trigger Efficiencies

Sophisticated, flexible algorithm using geometry and quality to achieve:• good efficiency • reasonable rates• ghost suppression

DTCSCRPCGMT smart

GMT ORGMT ANDGMT smart

Muon Trigger Efficiency

GMT Efficiency

Optimal combinationOptimal combinationhigh efficiency, small ratehigh efficiency, small rate

2.087.4AND

2.997.3SMART

5.498.1OR

Rate

kHz

for 14

GeV

GMT Option

Rates for L=2x1033 cm-2s-1


Hadron Calorimeter

The Global Muon Trigger adds information to muon candidates by correlating them with calorimeter regions. It confirms muon candidates with MIP information and determines their isolation.

Barrel Hadron Calorimeter Forward Hadron Calorimeter


Global TriggerThe trigger decisiontrigger decision may be based on simple or more complex criteria, similar to data analysis:

• Logic combinations of trigger objects sent by the Global Calorimeter Trigger and the Global Muon Trigger Best 4 isolated electrons/photons ET, , Best 4 non-isolated electrons/photons ET, , Best 4 jets in forward regions ET, , Best 4 jets in central region ET, , Best 4 -Jets ET, , Total ET ET

Total ET of all jets above threshold HT

Missing ET ETmissing, (ET

missing) 12 jet multiplicities Njets (different ET thresholds and -regions) Best 4 muons pT, charge, , , quality, MIP, isolation

• Thresholds (pT, ET, NJets)

• Optional topological and other conditions (geometry, isolation, charge, quality)


Global Trigger Algorithms

Logical CombinationsObject Conditions

128 flexible algorithms running in parallel are implemented in programmable logic devices. The trigger decision (Level-1-Accept) is a function of the 128 trigger algorithm bits (for physics). 64 more technical algorithms are possible.

eis.(1)

eis.(2)

ET(1) > ET(1)threshold

ET(2) > ET(2)threshold

0o ≤ φ()<360o

0o≤φ()<360o

70o≤φ()-φ()<90o

+(1)

μ-(2)

pT(1) > pT(1)threshold

pT(2) > pT(2)threshold

0o ≤ φ(1) < 360o

0o ≤ φ(2) < 360o

170o ≤ |φ(1) - φ(2)| < 190o

ISO(1) = 1, ISO(2) = 1MIP(1) = 1, MIP(2) = 1SGN (1) = 1, SGN(2) = -1

ETmissing

OR

Particle Condition formissing ET

Particle Conditions for muons

Particle Conditions for isolated electrons

ET(eis.) > ET(eis.)threshold pT(μ) > pT(μ)thresholdET

missing > ETthreshold

OR

ALGORITHM AND-OR

ANDAND

eis .

ETmiss ing

eis . μ


Global Trigger Boards

Every 25 ns the Global Trigger takes the decision to reject an event or to make it available to the High Level Trigger for further consideration. It consists of the following electronics boards:

PSB (Pipelined Synchronizing Buffer) Synchronization of inputs (7 modules)GTL (Global Trigger Logic) Logic (1-2 modules)FDL (Final Decision Logic) Trigger decision (1 module)TCS (Trigger Control System Module) Central trigger control (1 module)L1A (Level-1 Accept Module) Distribution of trigger decision (1 module)TIM (Timing Board) Timing (1 module)GTFE (Global Trigger Frontend) Readout (1 module)

PSB (Pipelined Synchronizing Buffer) GTL (Global Trigger Logic)


Trigger Control System and Timing

Trigger Control System Module Timing Module

The TCS Module controls the data taking based on fast status signals sent by the subsystems. The Timing Module is used for the distribution of the LHC clock.


Physics, Software, Management

– Trigger studies (Level-1, High Level Trigger)– Software for testing and operation of the trigger hardware– Coordination of the complete level-1 trigger software– Software for the reconstruction of muons

– Preparations for physics analysis, especially with studies in the field of Supersymmetry

– Membership in CMS Management Board– Membership in Editorial Boards for Trigger and Physics Reconstruction and Selection


Summary

The CMS-Trigger Group of the The CMS-Trigger Group of the Vienna Institute for High Vienna Institute for High Energy PhysicsEnergy Physics is responsible for the Level-1 is responsible for the Level-1 Drift Tube Drift Tube Track Finder,Track Finder, the the Global Muon TriggerGlobal Muon Trigger and the and the Global Global TriggerTrigger and is developing software for triggering. It is and is developing software for triggering. It is working on the working on the reconstruction of muonsreconstruction of muons and is and is performing studies for performing studies for physics analysis,physics analysis, in the field of in the field of supersymmetry.supersymmetry.

The current group members are:The current group members are:Scientists (physics, electronics, computer science):Scientists (physics, electronics, computer science):J. Erö, M. Jeitler, A. Nentchev, J. Erö, M. Jeitler, A. Nentchev, N. Neumeister, P. Porth, N. Neumeister, P. Porth, H. Rohringer, H. Sakulin, H. Rohringer, H. Sakulin, J. Strauss, A. Taurok, C.-E. WulzJ. Strauss, A. Taurok, C.-E. WulzTechnicians:Technicians:H. Bergauer, Ch. Deldicque, H. Bergauer, Ch. Deldicque, K. Kastner, M. PadrtaK. Kastner, M. PadrtaStudents:Students:M. Galánthay, S. Kostner, B. Neuherz M. Galánthay, S. Kostner, B. Neuherz

cms - trigger recfa-meeting leopold-franzens-universität innsbruck, 26 march 2004 presented by...

Documents

good muon trigger

dedicated trigger chambers

trigger cross sections

track candidates

eta track finder track

atp3wcmstrigger slide

lower data volume trigger

rack drift tube track