Muon Level-2 Outline

Level-1 / Level-2 Muon-ID

Example Algorithm

Performance

The Level-2 Muon TriggerThe Level-2 Muon Trigger

A. Maciel (N.I.U.)

Muon-L2

ITEP -- LMU(Munich) -- Nevis Labs -- NIUITEP -- LMU(Munich) -- Nevis Labs -- NIU

Arthur Maciel (N.I.U.)For The DØ b-ID Vertical Review; FNAL 04-04-01

Muon Level-2 OutlineMuon Level-2 OutlineData processing happens in three stages;

(1) SLIC’s (track segment finding)

(2)ALPHA preprocessor (track assembly)

(3) GLOBAL Level-2 (trigger decisions)

INPUT PROCESSING OUTPUT

Muon Front

End Data

L1 Data

Pattern Recognition

Re-Format

A - Layer Track Stubs

BC-Layer Track Stubs

L1-objects (+Aphi)

Compare all SLIC reported objects, search for matches

Assemble matches (or singles) into final L2 muon candidates

Report track params. and ID-quality to L2(global) and L3(seeds)

• Relate muon L2 candidates to other L2 objects, report triggers

A. Maciel (N.I.U.)

Muon-L2

(C-code on T.I. DSP’s)(C-code on T.I. DSP’s)

(C++ on Linux)(C++ on Linux)

(C++ on Linux)(C++ on Linux)

Overview of Muon L2 AlgorithmsOverview of Muon L2 Algorithms

• Pre-Global muon ID is based on muon system only, no cross

referencing among different subdetectors (L1 CFT Pt-thresh).

• Track segment finding for A and BC layers separately. Run1 Pt.

• Segments built from both wire and scintillator elements.

• Calib: central wires have drift and φ(ΔT), Scints are T0 subtracted.

• L2 reports single-cell-wide 3D tracks in (Pt,η,φ) coordinates.

• Central PDT (A)segments must satisfy track residual requirements.

• No vertexing, but hit patterns must be compatible with int. region.

• Added resolution (over L1) in track counting, pointing and timing.

• L2 candidate searches are not biased by or related to L1 results.

A. Maciel (N.I.U.)

Muon-L2

L2-Global Muon Candidates L2-Global Muon Candidates

• Global L2 has two main functions; object selection

and object relations (objects: Jet,EM,MEt,MU,TRK,IP)

• Muon selection; (Number, Pt, range, Quality)

• Muon relations;

– Angular separation, Dimuon mass [CFT resolution]

– Isolation, muon inside jet, track match (Pt,η,φ) , IP

• Global can request object matches, but cannot do

track re-fits, or ID building beyond CFT(Pt,η,φ)

• Muon candidates sent to Global are also sent to L3

as seeds for data (detector module) unpacking

ALPHA

A. Maciel (N.I.U.)

Muon-L2

Overview of the L2mu Software ProjectOverview of the L2mu Software Project

A. Maciel (N.I.U.)

Muon-L2

SLIC Driver:• Init / Config / Test Suite• Soft & Hard Resets, SCL init.• Run control & monitoring

DSP-OS:• Boot Kernel (Init /Config /Test)• Data I/O ; driver and interrupts• Data I/O ; memory management

DSP-Alg:• Interface w/ mem. management• (A,BC)x(Central,Forward) , L1• Error handlers, Monitoring

DSP-5:• Event sort/build/format• Full readout events, M&P• Monitoring interface w/ VME

ALPHAS:• Worker ; Gen.Strategy, finalize formats• Administrator&Global (expecting a free ride)

Simulator:• Framework• Raw L2 data• DSPs and Alpha

MC Studies:• Backgrounds

• A-layer punch• Thin region punch• Halo and Multip.Int. (unmatched stubs)

• Eff./Rej./Rates• L2 (Pt,η,φ) resolution

1

2

3

4

5

6

7

C & Asm C ++

Muon Level-2 Outline

Level-1 / Level-2 Muon-ID

Example Algorithm

Performance

The Level-2 Muon TriggerThe Level-2 Muon Trigger

A. Maciel (N.I.U.)

Muon-L2

ITEP -- LMU(Munich) -- Nevis Labs -- NIUITEP -- LMU(Munich) -- Nevis Labs -- NIU

Arthur Maciel (N.I.U.)For The DØ b-ID Vertical Review; FNAL 04-04-01

CFT φ wedge

octant widescint match(η wedge)

MTC05 MTC10

PDT centroid

region widescint match(φ wedge)

L2; SLIC+ALPHA

3D track resolution (counting) A & BC segments separately A (3/4 hits) BC (3/6 hits) A & BC crossing octants High PT A-layer w/out BC η dependence of hit patterns (pointing to interaction region) simultaneous look at 2 or 3 scintillator times on track

SLICs receive calibed data from Front Ends;PDT drift distances and phi (1st T-pair only)SCT T0-subtracted times (w.r.to tile center)MDT hit addresses only, no drifts.

andFrom L1; MTC05, MTC10, MTM, MCEN...

No cross referencing amongdifferent subdetectors before

Global-L2(except L1 CFT-confirm & thres.)Run-1 muon PT (from toroid only)

No (muon) Z-vertex point back

A. Maciel(NIU)

L2 muonL2 Muon ID

L1

• We can expect a rate reduction 2 from tracking• Extra rejection can come from;

Tighter time gates Event-wide inspection

L2 is both an object-ID trigger and a physics trigger

Pt 4 GeV (2,2)GeV (2,4)GeV

η < 1 1 0.2

η < 1.5 2 2 0.2

η < 2 4 10

~Expected L1 Muon Rates (KHz)L1 muon bandwidth ~few KHz

5 MHz 10 KHz 1 KHz 20 HzL1L1 L2L2 L3L3

singletrack

L2L2 >~

L2 Impact on L1 Muon-ID

Smallest granularity 3D tracking, improved wire-scint and L-L correl

More accurate object counting; removes multiple triggers (stubs) resolves closely spaced tracks

Pt matching to L1 threshold

Narrower rejection time gate

Scint-TOF discrimination for Prompt - Slow - Out of Time

Recover crossing octant tracks

η dependence of hit patterns

CFT φ wedge

MTC05

region widescint match(φ wedge)

octant widescint match(η wedge)

MTC10

PDT centroid

L1 Muon ID

calib

punch

pointin

gA. Maciel (N.I.U.)

Muon-L2

non-CFT fw

d.

dimuons

MSP se

arches

(Pt,η,φ)

Comments for L3

• “Muon-subdetector-only” ID largely done @L2

• Exploit other subdetectors !

• Muon vertex - MTC vertex - min.H vertex; is the muon vertex compatible with the rest of the event ? (multiple interactions)

• Kinematics refitting, dimuon masses, reln to other phys. objects

• Back to back tracks - correlate scint times (low Pt dimuons)

• Number of hits on track (L2 fixed @6) - combinatorics(fwd)

T

A. Maciel (N.I.U.)

Muon-L2

Muon Level-2 Outline

Level-1 / Level-2 Muon-ID

Example Algorithm

Performance

The Level-2 Muon TriggerThe Level-2 Muon Trigger

A. Maciel (N.I.U.)

Muon-L2

ITEP -- LMU(Munich) -- Nevis Labs -- NIUITEP -- LMU(Munich) -- Nevis Labs -- NIU

Arthur Maciel (N.I.U.)For The DØ b-ID Vertical Review; FNAL 04-04-01

SLIC AlgorithmsSLIC Algorithms

Ave. time budget = 25 µs

Track stub finding (wire+scint)driven by lookup tables with:

valid wire hit patterns wire geometry for track fit valid wire-scint correlations

PDT hit triplet

Scint. z-rows

beam

line

PDT

Central A LayerCentral A Layer

A. Maciel (N.I.U.)

Muon-L2

obs: wire-only or scint-only stubs are not being considered

• Sweep octant in search for wire triplets• check that matching z-row has been hit• check triplet validity, calculate residual• assign scint time and phi, wire eta• report stub, continue octant sweep

A 3x4 Search Window

Valid hit-triplet Patterns are listed on a lookup table

Table has η dependence. One A-layer octant holds 40 valid patterns. At each η, only up to 18max. are possibly valid.

Track receives a detector(η,φ)

Track η is given by innermost cell

Track φ is given by Aφ or PixelPDT ΔT (triplet average) resolves doubles

L2 Muon 3D Track PointingL2 Muon 3D Track Pointing

sigma = 0.09LSB(η) = 0.05

A. Maciel (N.I.U.)

Muon-L2

A Layer Track Segment

PDT Hit Triplet. Wire Positions are;

( z , y ) for cells in , mid , out

d = Signed Drift Distances

Hit Position = ( z+d , y )

din

dmid

dout

det zi + di zm + dm zo + do = 0

yi ym yo

1 1 1

The straight line segment constraint

determines a track stub residual equation for the drift times,

c o | d | + Offset = Res(dim L) where…

z

yRequiring 3 cells hit (out of max.=4)

A. Maciel (N.I.U.)

Muon-L2

Track Stub Residual Equation

c o | d | + Offset = Res(dim L)

Track Stub Residual Equation

c o | d | + Offset = Res(dim L)

Offset = 1 zo zm zi

yo – yi yo ym yi

1 1 1

Cout = sign x (ym – yi) / (yo – yi)

Cin = sign x (yo – ym) / (yo – yi)

Cmid = sign x - 1

Offsets are in 1 1

correspondence with

Triplet “patterns”

PDT triggering must test residuals over all valid sign combinations

Coefficients are in 1 1

correspondence with

missing deck #

A. Maciel (N.I.U.)

Muon-L2

Muon Level-2 Outline

Level-1 / Level-2 Muon-ID

Example Algorithm

Performance

The Level-2 Muon TriggerThe Level-2 Muon Trigger

A. Maciel (N.I.U.)

Muon-L2

ITEP -- LMU(Munich) -- Nevis Labs -- NIUITEP -- LMU(Munich) -- Nevis Labs -- NIU

Arthur Maciel (N.I.U.)For The DØ b-ID Vertical Review; FNAL 04-04-01

µsec

window sweep

search one

search all

DSP Timing

A. Maciel (N.I.U.)

Muon-L2

DSP EvaluationDSP Evaluation

Trigger code in assembly format

Download trigger code and tables

Each A layer DSP holds one octant

Code and tables are octant specific

Timing is for single track events

Backgnd: 5% random hits added

DSP internal memory has 64kB

Code and table have ~20kB each

DSP management code under study

SLIC: 4 worker DSPs, one manager

Central-A: 8 DSPs in parallel

Central-BC: 8 SLICs in parallel

The L2 – Muon Object FindingThe L2 – Muon Object Finding

3x4 Search Window

A-layer PDT

For each search window, find all valid hit triplets, deck

ordered inside out.

Each triplet is tested against trigger table for track

segment and drift residual (here no scintillator match)

A. Maciel (N.I.U.)

Muon-L2

15

.. 1 8 *

32

5

6 7

z

y

. . .24 columns

Four decks

4

ROAD = + 009 - 011 - 013 +015

Triplet = +009 –013 +015 ; Pattern = 0,0,1

*

*

*

*

ROAD = + 025 + 026 - 028 +030

Triplet = +017 +018 +022 ; Pattern= -1,-1, 2

*

Central A-Layer PDT

Nb; patterns are triplet shapes, and have Z – translation invariance

A triplet “pattern”is defined as twocell projections,and the missingdeck number

1

Barrel = 1 , 2 , 3

Cell 0Coln 0

Col_in = 3

. . . 95

89

10

12

14

9

15

11

13 28

24

26

column

A. Maciel (N.I.U.)

Muon-L2