DD Upgraded DUpgraded D Detector and Detector and B PhysicsB Physics

• D Detector Upgrade at Run II Overview

• Focus on Inner Tracker and the Trigger

• B physics in D, mainly sin(2)

• Preliminary performance report using real

data

Collider – Accelerator Department, June 6, 2002 Kin Yip (Physics Dept.)

DD

CDFD0

4.82.32.5interactions/xing

1323963500bunch xing (ns)

10517.33.2 Ldt (pb-1/week)

5.2x10328.6x10311.6x1030typ L (cm-2s-1)

1.961.961.8s (TeV)

140x10336x366x6#bunches

Run 2bRun 2aRun 1b

Tevatron upgrade:• Increased energy

1.8 TeV 1.96 TeV• Increased luminosity

0.1 fb-1 2 fb-1 15 fb-1

Detector upgrades:• Higher event rates and

backgrounds (electronics, DAQ, trigger)

• Considerable expansion of the physics capabilities

(Run 1) (Run 2a) (Run 2b)

Physics opportunities: • Top • Higgs• New Phenomena• Electroweak • Beauty• QCD

The Tevatron Run IIThe Tevatron Run II

Run II Physics Prospects: High-Run II Physics Prospects: High-ppTT

Some highlights Top physics Electroweak

Improvements in Run II increased statistics better jet energy

measurement better b-tagging

silicon tracker w/ preshower info

better muon finding

Precision Measurements MW from ~80-90 MeV to ~40

MeV per experiment

Mtop from ~6 GeV to ~2-3 GeV per experiment

There is a chance that Higgs may be discovered at Fermilab …

DD

Constraints to Higgs

precision measurements of W, Z bosons, combined with Fermilab’s top mass, set an upper limit of MH ~ 212 GeV

direct searches for Higgs production exclude MH < 114.1 GeV

RUN II(2 fb-1 per experiment)

DD The DØ DetectorThe DØ Detector

The DØ upgrade builds upon the strengths of the existing detector (excellent calorimetry, muon coverage) and augments it with a high resolution Silicon/Scintillating Fiber tracker.

•calorimeter: replacement of preamps/shapers

•muon system: –replacement of muon chamber readout electronics

–Iarocci drift tubes replace forward muon chambers

–central and forward scintillator pixel layers enhance trigger capability.

•DAQ & trigger: add track and vertex triggering, add buffering, add processing power

•central tracker: –2 T supraconducting coil inside r=70 cm calorimeter bore

–lead/scintillator preshower detector with fiber/VLPC readout

–16 layer SciFi/VLPC tracker (80k channels)

–4 barrel / 16 disk Silicon tracker (1M channels)

•forward tracker/preshower: scintillator cells with fiber/VLPC readout

DD DØ TrackingDØ Tracking

calorimeter cryostat

1.1

1.7

1.3 m

50

cm

Solenoid 2 Tesla superconducting

Central Fiber Tracker (CFT)– 16 doublet layers of Sci-Fi ribbon

• 8 axial (parallel to the z-axis) TRIGGER

• 8 stereo(2o pitch), NOT used in TRIGGER

– 76,800 830 m fibers (multiclad)

– coverage: 20<r<52cm, polar angle to ~22– In the radial plane, CFT is divided into 80

sectors (4.5)

• Silicon Tracker

• Preshowers• Central

• Forward

z-axis

DD Designed DØ Upgraded Detector PerformanceDesigned DØ Upgraded Detector Performance

– Good Momentum resolution: • dpT/pT

2 ~ 0.002 (Silicon + Scintillating Fiber Trackers)

– High tracking efficiency:• at least 95 % (disks)

– Vertex Reconstruction:• primary vertex: vertex ~ 15-30 m (r-), 50 m (r-z)

• secondary vertex: vertex ~ 40 m (r-) , 100 m (r-z)

– Excellent lepton coverage, trigger and ID efficiency: • muons: pT > 1.5 GeV,

• electrons: pT > 1.5 GeV

– Impact parameter trigger

DD Cosmic Ray Test Results:

Scintillating Fiber Tracker (axial and stereo fiber doublets) with full electronic readout chain

Doublet position resolution: ~100 m Doublet Efficiency: > 99.5%

probability that signal from a doublet is greater than threshold

CFT: Performance (cosmic ray CFT: Performance (cosmic ray test)test)

Axial(z)

Stereo(u,v)

CFT ribbons: r– view of an alternative stereo and axial (interlocking) doublet

configuration

DD Particle signatures with preshowers: (e.g., FPS) “MIP” Layer + “Lead” radiator + “Shower” Layer

electron pion o; ()

Particle signature in FPS four layers: MIP and Shower(50 GeV MC generated events, passed through DØ Detector Simulater)

Particles traversing the FPS detector:

L1L2-Pb-L3L4 L1L2-Pb-L3L4

Particle MIP deposition Shower cluster (FPS Layers 1,2) (FPS Layers 3,4)

“Upstream” “Downstream”

electron Yes narrowpion o No widepion Yes little energy (MIP)muon (MIP hit) (MIP hit)

DD Trigger SchematicTrigger Schematic

5-10 kHz128 bits

1000 Hz128 bits

20-50 Hz

L2100s

L14.2 s

L3 100 ms

50 nodes

Framework

7 MHz, 132 ns crossing times*

Accommodate : L=2x1032cm-2 s-1 &

Bunch Crossings 132 ns *

Maintain Run I e, jet, acceptance

Deadtime: <5% (due to pipeline)

L2FW:Combined objects (e, , j)

L2FW:Combined objects (e, , j)

L1FW: towers, tracks L1FW: towers, tracks

L1CAL

L2STT

Global L2

L2CFT

L2PS

L2Cal

L1PS

L1CFT

L2Muon

L1Muon

L1FPD

7 MHz 10 kHz 1 kHz

CAL

FPSCPS

CFT

SMT

Muon

FPD

Detector L1 Trigger L2 Trigger

DD L1 Trigger OverviewL1 Trigger Overview

Fiber hit pattern recognition in the CFT and PS to

look for tracks consistent with momentum PT > 1.5 GeV/c

Match with the Calorimeter showers and Muon hits

CPS

CFT

CAL

e-

PS & CAL are matchedfor each quadrant

DD VVisibleisible LLightight P Photonhoton C Countersounters

Scintillating Fiber Optical Connector

Waveguide Fiber

Mirror

Photodetector Cassette Electrical Signal Out

Cryostat

VLPC

DD ANALOG/DIGITAL BOARDSANALOG/DIGITAL BOARDS

ANALOGFRONT ENDBOARD

DIGITALFRONT ENDBOARD

ANALOGFRONT ENDBOARD

CASSETTEand VLPCs

FIBERS

SERIAL LINKSTO MUON,RECEIVERS, etc.

2 Trigger Sectors per board

8 or 12 MCM board

MIXING BOX

LVDS links (> 20Gbits/s)

• Each MCM (Multi Chip Module) has 1 SVX(ADC) and 4 SIFT (discriminator);• CFT axial fiber signals are all managed by “8 MCM” boards;• CPS/CFT(stereo)/FPS fiber signals are all mixed in the “12 MCM” boards;

DDVLPC SIFT

SIFT

SIFT

SIFT

VLPC

QinX% of Qin

1-X% of Qin

Qin X% of Qin

1-X% of Qin

Threshold A

18

18

18

18

18

18

SVX72 inputs

Threshold B

18Discriminator Out

18Discriminator Out

18Discriminator Out

18Discriminator Out

8 Data,1 DVALIDto Level 3

MCM

* Charge splitting only for PreShower

Each CFT/CPS Analog board

has 8/12 MCM’s

CFT and PS Front-End

DD Track Trigger AlgorithmTrack Trigger Algorithm

• There are 80 sectors in CFT, each subtending 4.5;

• Seamless tracking requires fiber sharing between nearest sectors; • Tracks with PT1.5 GeV are contained within 2 neighbor sectors;

• Fiber hits are transmitted from a sector to either side for track matching.

CFTSector 1 CFT

Sector 2

TrackSector boundary

No crack in tracking

DD Track Trigger Algorithm Track Trigger Algorithm (cont.)(cont.)

• Basic algorithm : matching hit patterns in all 8 layers (A,B, …,H) with a pre-programmed set of “equations” ;

• Compute allowed trajectories ( equations ) analytically for all possible tracks for

momentum PT 1.5 GeV;

• based on the fact PT magnetic field strength (2T) radius of curvature;

• equation - a set of 8 fiber indices;

• There are about >16000 equations for each sector ;

• Algorithm uses 8 out of 8 doublet layers;• with an option to require only 7 out of 8 layers at highest PT later in the run;

• Use the outermost layer (8th layer, H layer) as the anchor layer (reference layer)

where there are 44 fibers in each sector.

DD Track Trigger Algorithm Track Trigger Algorithm (cont.)(cont.)

• The equations can be downloaded to the Programmable Logic Devices (PLD) on the FE boards as many times as you like;

• Use the largest PLD’s available (each with several 105 logic gates) to handle the trigger logic;

• Use HDL (Hardware Description Language)* to implement the tracking logic like:

T1013172227323945 = A[10] AND B[13] AND C[17] AND D[22] AND E[27] AND F[32] AND G[39] AND H[45]

( There are >16000 of them in each sector ! )

* There are quite a few ways (schematic/various languages) to program the PLD’s.

DD Track Equations in HDLTrack Equations in HDL

T1520243035404652 <= AL(15) AND BL(20) AND CL(24) AND DL(30) AND EL(35) AND FL(40) AND GL(46) AND HL(52) ;T1520253035404652 <= AL(15) AND BL(20) AND CL(25) AND DL(30) AND EL(35) AND FL(40) AND GL(46) AND HL(52) ;T1520253035414652 <= AL(15) AND BL(20) AND CL(25) AND DL(30) AND

EL(35) AND FL(41) AND GL(46) AND HL(52) ;T1620253035404652 <= AL(16) AND BL(20) AND CL(25) AND DL(30) AND EL(35) AND FL(40) AND GL(46) AND HL(52) ;T1620253035414752 <= AL(16) AND BL(20) AND CL(25) AND DL(30) AND EL(35) AND FL(41) AND GL(47) AND HL(52) ;T1620253036414752 <= AL(16) AND BL(20) AND CL(25) AND DL(30) AND EL(36) AND FL(41) AND GL(47) AND HL(52) ;

p(8) <= T1520243035404652 OR T1520253035404652 OR T1520253035414652 OR T1620253035404652 OR T1620253035414752 OR T1620253036414752 ;

Equations with the H-bin and PT binsare OR-ed together.

DD Track Trigger Algorithm Track Trigger Algorithm (cont.)(cont.)

• Input fiber patterns are matched with the equations tracks at certain (PT,) bin;• A matrix of PT (H fiber position) :

PT

• Scan the matrix “horizontally” in groups and put in priority encoder which outputs the indices of PT bins with the highest priority;1-D list of indices and concatenated in a binary tree structure down to a list of 6 (tracks with the highest PT) in each PT threshold; A mixture of parallel/serial modes to reduce latency while keeping resources low.

0 1 2 3 4 5 6 7 8 9 10 111 0 0 1 0 0 0 0 0 0 0 ...2 0 1 0 0 0 0 1 0 0 1 …3 0 1 1 1 0 0 0 0 0 0 …4 0 0 0 0 0 0 0 0 0 0 …5 0 0 0 0 0 0 0 0 0 0 …6 1 0 0 1 0 0 0 0 0 1 …7 1 0 1 0 0 0 0 1 0 0 …… … … … … … … … … … … …

DDFIND CFTTRACKS(4 largeFPGAs)

BASIC DATA FLOW DIAGRAMCFT/CPS AXIAL TRIGGER DAUGHTERBOARD

FOUR Pt THRESHOLD BINS

FIND CPSCLUSTERS *

SELECT THE SIX HIGHEST PT TRACKS FROM ALL Pt THRESHOLD BINS

to MUONtrigger manager

MATCH CLUSTERS TOTRACKS* AND TRACKS* TO CLUSTERS

CHECK FOR ISOLATEDTRACKS AND CLUSTERS

FORM COUNTSFOR L1

STORE TRACKSIN FIFOs

STORE CLUSTERSin FIFO

FORMAT L2 DATA

L1 data is a list of counts of foundtracks and clusters.

L2 data is a list of found tracksand clusters. Up to24 tracks and 8 clusters can be reported per sector.

to CFTtriggermanager

* this logic is contained in one of the large FPGAsR

AW

CF

T/C

PS

AX

IAL

DA

TA

fro

m D

FE

mo

the

rbo

ard

fnct_blk.ds418 oct 1999

L1

L2

MUX

BACKEND FPGA

*

DD PLD SimulationPLD Simulation

Testing Result:•Algorithm and timing have been tested in the vendor software simulation and implemented in a trigger test board with PLD’s;• The measured timing in the real PLD’s agrees very well with the simulation and the result of the trigger logic is what is expected.

Tracking logic completed < 85 ns

simulationresult

DD Monte Carlo SimulationMonte Carlo Simulation

• FORTRAN C++ code in Run II software framework• Full monte carlo simulation studies using the D upgrade configuration in GEANT (dgstar) have been done in various physics samples.

• Single electron/muon samples are used to tune the efficiency of the trigger algorithm. For PT >3 GeV, efficiencies:

•>97% for muons and •~95% for electrons,

limited by multiple scattering and various radiation effects.

•Plot shows how the CFT trigger efficiencies when different sets of equations (belonging to certain PT thresholds) are used.

DD CFT track efficiencyCFT track efficiency

CFT Track efficiencies only for tracks from beam spot

DD Trigger Efficiency vs Impact parameterTrigger Efficiency vs Impact parameter

DD # of Equations vs P# of Equations vs PTT/offset/offset

NPT ~ 1/PT

DD Typical B physics spectrumTypical B physics spectrum

B Physics requires triggers at Low Pt

DD Track BinningTrack Binning

• PT binning yields sharper turn-on than offset binning

offset = [(projection of H layer fiber hit on A layer) - A layer fiber hit] in units of fibers

} 50%

} 20%

}15%

}15%

Eqn #

DD Trigger Tracking AlgorithmTrigger Tracking Algorithm

• From Monte Carlo simulation studies, we can limit ourselves by allowing only 2

tracks in each PT bin and 6 tracks in each of the 4 PT thresholds in each sector virtually

without losing any tracking efficiency.

• Need 2 tracks because of extra hits at high luminosity which create a fake track

(7 points on original track and 1 fake).• Fake track can be higher or lower in PT than the real one.

• ~90% — only 1 track passes through a fiber ;

• ~10% — 2 tracks pass through a fiber.

• Only 48 tracks per broadcaster.

1 track2 tracks

ttbar~ 7%< 1%

Z bb_bar~ 10%< 1%

Inefficiencies

DD Misalignment Misalignment increase in number of CFT increase in number of CFT track equationstrack equations

The other end

Case considered :

CFT Cylinder Axis

Shift

One end

CFT CFT

Cylinder surface

misalignment

DD Misalignment EffectMisalignment Effect

• If I give a d/dz such that at the end of C layer, fibers are gradually (and linearly)

shifted by 4 mils ( like a stereo layers ) almost no inefficiency.

• The outer layers are more susceptible to misalignment effect.

Interaction point

H

A

C

CFT layers

z-axis

DD Large production cross section

Even larger inelastic cross section

(S/B10-3) specialized triggers:

Single lepton triggers

Dilepton triggers such asJ/ + -

Track triggers moved to L1 (RunII)

In Run II, L2 trigger on displaced tracks using SVX will allow CDF/D to trigger purely hadronic B decays and study such asB0 +, Bs Ds

+ ...

Precise 2nd vertex reconstruction

B Physics challenge at Tevatron

μb150)bbpσ(p

nbBBee 1)(

nbbbee 7)( At 2 TeV

At (4S)

At Z0

DD CP violation can be manifested as:

CP violation in the decay

CP violation in the mixing if the neutral mass eigenstates are not CP eigenstates

CP violation in the interference between decays with and without mixing to a CP eigenstate

)0()0(

)0()0(

FBFB

FBFBaF

CP Violation in CP Violation in B B JJ// + K + KSS

B0

B0

J/ K0s B0

B0

J/ K0s

)0()0( FBFB

Time dependent asymmetry

V*td

b

b

d

dt

tB0 B0W W

Direct and mixed decays interfere with different amplitudes - leading to different decay rates into the same CP eigenstate:

CP VIOLATION

Direct and mixed decays interfere with different amplitudes - leading to different decay rates into the same CP eigenstate:

CP VIOLATION

DD The Cabibbo-Kobayashi-Maskawa MatrixThe Cabibbo-Kobayashi-Maskawa Matrix

tbtstd

cbcscd

ubusud

VVV

VVV

VVV

1)1(

21

)(21

23

22

32

AλiηρAλ

Aλλλ

iηρAλλλ

In SM, CP violation arises from a single (complex) phase in the CKM matrix (in Wolfenstein parameters):

– A and have been measured to a few percent (is the sin of the Cabibbo angle)

– CP violation is put into the formalism with the complex phase

– unitarity condition:

0*** udubcdcbtdtb VVVVVV

gives the unitarity triangle (1,0)

(0,0)

*

*

cbVcdV

tbVtdV

*

*

cbVcdV

ubVudV

(,)

( which transforms (u,c,t) to (d,s,b) and vice versa. )

DD Sin(2Sin(2) and CKM matrix elements) and CKM matrix elements

sin(2)

*

*

*

*

*

*

Imcscd

cscd

cbcs

cbcs

tdtb

tdtb

VV

VV

VV

VV

VV

VV

B0-B0 Mixing Ratio of K0-K0 mixing

)f(A

)f(A

2)1(2)1(2

*tbtd

*cbcd

VV

VVargβ

According to previous unitary triangle :

For Bd J/ + Ks , it involves

DDAsymmetry (in the Standard Model) is directly related to sin2:

= sin(2) sin(mdt)

Golden channel for sin( 2

0/00/0

0/00/0

)(

SKJBSKJB

SKJBSKJB

tACP

This is a “golden” channel due to:• readily accessible final states with small background• relatively large branching ratio• negligible theoretical uncertainty

• penguin amplitude is expected to be small since cc pair must be popped from vacuum• penguin diagram contribution to the asymmetry has the same phase as tree level

is one of the 3 angles in theunitary CKM triangle

DD Sin(2Sin(2) via) via B B J/ J/ + K + KSS

– full reconstruction of final state

• two V’s

• soft pions

– measure decay length

– tag flavor at production – same side flavor tag

• pion charge– opposite side flavor tags

• lepton charge

• jet charge

+

|Qjet| > 0.2

b

+ -

+

-

-b

J/

B

KS

Efficiency () and dilution factor (D)

D = 2 P – 1 = (NR –NW) / (NR +NW)

P is the correct tag probability

D2 is the tag’s effectiveness

Efficiency () and dilution factor (D)

D = 2 P – 1 = (NR –NW) / (NR +NW)

P is the correct tag probability

D2 is the tag’s effectiveness

DD BB JJ// K KS S ReconstructionReconstruction

• It looks like we can reconstruct KS + -.

DØ GEANT/Trig. Sim.

DØ Run II GEANT

(cm)

DD BB JJ// K KS S ReconstructionReconstruction

MCFAST (with vertexconstraint fit)

RECO

•Combined +- + -

invariant mass

•(before fit)

( GeV )

DD

Tag

D 2 (%) measured

CDF Run I

D 2 (%) expected

CDF Run II

Relevant

DØ difference

DØ capabilities

Same side 1.8 2.0 same 2.0

Soft lepton 1.7 e ID

coverage 3.1

Jet charge 0. 8 3.0 forward tracking 4.7

Opp. side K 2.4 no K ID none

Combined 9.1 9.8

Flavor TaggingFlavor Tagging

Note : Observerd AsymCP = D • AsymCP

DD Current Measurement of sin(2)

CDF Run I: sin2=0.79+0.41

-0.44(stat. +

sys.)

BABAR:sin2=0.75 0.09 (stat.) 0.04

(sys.)

BELLE:sin2=0.99 0.14 (stat.) 0.06

(sys.)

DD Sin2Sin2 Expectations for 2fb Expectations for 2fb-1-1

– (S/B ~ 0.75)

– D2 ~ 9.8 %

– t ~ 128 fs

mode J/ J/ e+e-

trigger eff. 27 20

reco’d events 40,000 30,000

0.04 0.05sin2 0.03

S

B

NDx

xe

d

td dx

1

1

2

41)2(sin

2

2222

For a time dependent analysis:

assuming luminosity ~ 2 fb-1

{ as in the report “B Physics at the Tevatron : Run II and Beyond”, hep-ph/0201071 [FERMILAB-Pub-01/197]. }

DD The Past YearThe Past Year

Run 2 startFirst Collisions

Detector commissioning,timing, improve electronics, DAQ and offline

InstrumentFiber Tracker

DØ detector roll-in

• About 40 pb-1 delivered so far• Used for commissioning of

– Detectors– Offline processing– Worldwide data access– Analysis

• e, , jets, EM and jet energy scales, etc.

~ 12 pb-1 now on

tape(SAM)

reconstructionprocessing

DD Silicon Microstrip Tracker StatusSilicon Microstrip Tracker Status

100% commissioned

Barrels: 95.2% operationalF-disks: 95.8% operationalH-disks: 86.5% operational

p-side pulse-height

1 MIP 4 fC 25 ADC counts

S/N > 10Efficiency > 96%

Work in progress:Integrating disks into tracking

Barrels+ disks

Barrelsonly

KS0+-

K0 signal, silicon standalone tracking

DD Central Fiber Tracker (CFT)Central Fiber Tracker (CFT)

- 20 cm < r < 51 cm

- 8 layers of axial and stereo 830 mm scintillating fibers

- ~12m long clear wave-guide to Visible Light Photon Counter (VLPC)

• 9K operating temperature

• 85% QE, excellent S/N

- ~77k readout channels

- Fast pick-off for trigger pT>3 GeV

DCA resolution ~ 60 m(unaligned!)

beam spot ~ 30-40 m

DCA: Distance ofClosest Approach

track

x

y

CFT tracks

(SMT+CFT) Global tracks

Completed CFT Mechanical

Fiber Tracker Electronics

Axial: completeStereo: recently

completed

DD Muon SystemMuon System

Mean = 3.08 ± 0.04 GeV

Sigma = 0.78 ± 0.08 GeV

Muons + CFT

J/ signal, central + fwd triggers work in

progress

J/ +-

Muon System

standalone

shielding

Muon system 100%

commissioned

DDx = 46 m;

y = 43 m;Data:

MC: r = 30-33 m for PV with ntracks > 14

Beam spot size = 30 m

After beam spot subtraction, very good agreement between MC and real data

Present status of the DØ tracker performance (2)

DDImpact Parameter resolution in data is close to Monte Carlo simulation

Present status of the DØ tracker performance

{ IP’s calculated using single tracks }

DD Trigger simulation running on real data

DD

Electron

MET

j1 j2j3

j4

Physics analysis is startingPhysics analysis is starting

e

ee

e

• Physics and object ID groups are very active

• Interesting events being collected, point to our future physics direction +MET candidate extra dimensions (ee+) W

candidate

– W+4jets = top candidates trilepton candidates (SUSY)

DD Future …...Future …...

• Finish detector commissioning

• Debugging, calibration, alignment

• Continue refining reconstruction algorithms

• Full tracking secondary vertexing, electron

id (J/ ee) …

• Complete triggers and improve DAQ

• Level 2 trigger coming online

• Level 1 central track trigger

Summer 2002

• Level 2 silicon track trigger

End summer 2002

• Hope for the best luminosity

Detector installed and hooked-up to VLPCs

Measure MIP response: light-yield 11.2 m clear light-guide doublet: 14.5 photoelectrons (light-

yield ~ 3-4 higher than minimum required for efficient tracking)

CFT: System PerformanceCFT: System PerformanceDD

Read-out Platform: Waveguides and VLPCs

Pulse Height

~14.5 pe

pT resolution

pT/pT ~ 8% for pT = 45 GeV at = 0

Importance for DØ E/p matching for e-id Calorimetry calibration Muon momentum resolution Charge sign determination

CFT: Performance (cont.)CFT: Performance (cont.)DD

DD Analog/Digital Front EndAnalog/Digital Front End

• 80 identical Analog Front End (AFE) boards mounted on 40 VLPC cassettes;

• 40 identical Digital Front End mother boards in two 6U VME crates ;

• each DFE mother board processes two sectors of the detector independently, one on each of two daughter boards ;

• In each daughter board, there are a few Programmable Logic Devices (PLD) involved to make trigger logic decisions– PLD is used because it is fast and can be reprogrammed;

• Collector/Broadcaster system (using the same DFE mother boards) to organize trigger information to be sent to L1 trigger framework and L2 preprocessor.

DD Truncation effectTruncation effect

DD Interspersed Barrel/Disk Design

6-silicon barrel sections (4-layers per barrel): (r- info) Layers 2, 4: double-sided, 2o-

stereo Layers 1,3 of 4 inner-barrels (about

z = 0): double-sided, 90o-stereo Layers 1,3 of 2 outer-barrels:

single-sided

F-Disks: (r- and r-z info) double-sided, 15o-stereo

H-Disks: (r- and r-z info) 2 single-sided detectors, 7o-

stereo

Operate at ~10 oC Total of 792,576 channels Read out by SVX-II chips

Barrels F-Disks H-Disks

Channels 387072 258048 147456

Modules 432 144 96

Si Area 1.3 m2 0.4 m2 1.3 m2

Inner R 2.7 cm 2.6 cm 9.5 cm

Outer R 9.4 cm 10.5 cm 26 cm

SMT Summary

Beryilliumbulkhead

Coolingchannel

72 ladders12 cm-long

4-layer barrel cross-section

Ladder (layer 4)

Carbon-fiberhalf-cylinder support

Silicon Microstrip TrackerSilicon Microstrip Tracker— Geometry —— Geometry —

DD Misalignment Misalignment increase in number of CFT increase in number of CFT track equationstrack equations

DD Precision measurement of charged particle tracks upto || < 3.0, near

interaction region Interspersed disk/barrel design Radiation hard to 1 Mrad Performance/Expectations:

Hit resolution: 10 m Secondary Vertex resolution

r-: 40 m r-z: 80 m

Tagging Efficiency at pT = 50 GeV ~50% for b-quark jets, ~10% for c-quark jets ~ 0.5% fake tag rate for u, d, s quarks jets

6 Barrelsections/modules

12 F-Disks

4 H-Disks(forward, high-)

z = 0

BeamLine

Silicon Microstrip Tracker (SMT)Silicon Microstrip Tracker (SMT)

DD How many BHow many Bd d may we get ?may we get ?

K

| GeV/ 4

402

090

27.0

)102()68.0)(06.0)(105(

),/,/(

21

%310.3)(| ,)(P : Acceptance

42.0)(

158483.3

trigger

54

eco

eco

Acc

c

r

r

trigger

BRLN

.

KJKJBBRBR

b f

ByB

Bbf

bb

B

ss

bbB

T

d

bb

assuming luminosity ~ 2 fb-1

DD Muon TriggersMuon Triggers

TriggerLevel 2

backg. (Hz)BJ/KS

efficiency (%)

Single (T1) PT > 4

(loose)~39 241

PT > 4(tight) 111

Dimuon:(T2)

PT > 2, 2 ~272 12±1

Overall

(T1) or (T2) 27±1

max level 2 rate for all DØ triggers is 1000 Hzmax level 2 rate for all DØ triggers is 1000 Hz

PT(B)> 4 GeV and || < 3

DØ GEANT/Trig. Sim.