status of dØ

Axel Naumann, DAxel Naumann, DØØUniversity of Nijmegen, The University of Nijmegen, The

NetherlandsNetherlands

Status Of DØ



19 Dec 200219 Dec 2002NIKHEF Annual Scientific MeNIKHEF Annual Scientific Meetingeting

22

Overview

Detector

Data• Luminosity• DAQ

Physics




33

The DØ Detector

All elements in place!

Commissioned: forward preshower FPS, forward proton detector FPD, level 1 central track trigger CTT

Silicon track trigger STT under construction

Fundamental change in DAQ: Switch to ethernet based DAQ very successful

Data taking efficiency >75%

>50pb-1 available for Moriond




44

The DØ Detector

New for RunII:• 2T solenoid• silicon tracker

Rebuilt• central tracking• part of calorimeter and muon system• trigger system




55

Detector: Silicon Tracker

Increase of bias current consistent with expectations, infers depletion voltage exceeds spec @ 4fb-1

p-side pulse-height (ADC)

p-side pulse height1 mip ~ 25 countsSignal/Noise ~ 12Layer efficiency ~ 97%

Integrated Lumi (fb-1)0.02 0.04 0.06

Layer 1,2 Bias Current

Bia

s C

urr

en

t




66

pT (GeV)

Significant improvement expected from alignment with data in near future

Detector: Tracking Performance

Survey-only alignment constants

width = 36 m(beam) = 30 m

= 20 m

KS +–

first SMTalignment - it helps!




77

Detector Calorimeter performance

Run II High ET 3-jet

eventET

: 110, 240, 310 GeVEt

miss : 8 GeV

Liquid argon calorimeterwith uranium absorber

Channel Count: 99.9%

J/ e+e-




88

Detector: Trigger, DAQL1: Cal, Muon available; CTT commissioning underway

L2: operating with CAL, Muon, Global; CTT, PS commissioning underway, STT expected to be operational spring 2003 (huge progress this year from prototype to production)

New ethernet based DAQ: Meets 1kHz L2 accept specs

Spec: 5 kHz

1000 Hz 50 Hz

tape

Peak: 1.2 kHz 50 Hz 1000 Hz

Level 2Level 1 Level 3

Operating: 0.7 kHz 50 Hz 300 Hz




99

Tevatron

Luminosity major concern: Tevatron and DØ DAQ performance in the beginning far below expectations (“got little beam and didn’t record events”)

Official lumi goal for RunIIa: >5*1031cm-2sec-1, integrated lumi of 2fb-1; actual limit believed to be 2*1032cm-2sec-1

Main luminosity issues for DØ:• Tevatron delivered lumi: p-bar injection; helix

tuning, cooling and losses; many more• DØ DAQ system: readout, triggers, event

building etc (see above)




1010

Tevatron

Every performance improvement evident in the luminosity performance plot has been associated with a specific modification to the accelerator complex.

Major modifications since January 1, 2002:Accumulator->Main Injector transfer opticsAdjustment of tunes during low beta squeezeModified injection helix in TevatronProton beam loading compensation in Main InjectorAccumulator (stochastic) cooling upgradeAccumulator shot latticeAntiproton beam loading compensation in Main

InjectorTevatron beam line tuner (BLT)Tevatron tune/coupling drift compensationTevatron transverse dampers

Beams division guy: (1.15)10 =4.0




1111

Tevatron: Plans

January 3.5 week + summer shutdown used for maintenance and improvements

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FY03 Base plan Achieved FY03 Stretch Plan

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2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Fiscal Year End

Run

II In

tegr

ated

Lum

inos

ity (f

b-1

)

10/02 Projection Stretch 10/02 Projection Base

End of Run IIbDetector upgrades complete

Limit of Run I Silicon RunIIb prospects: R&D still going on, official “baselining” in a few days (“DØ’s Christmas present”)




1212

DØ: LuminosityLuminosity vs. date

12/0

0

09/0

2

Tevatron delivered luminosity in the beginning below expectations; now catching up rapidly

Reason why lumi is

essential:




1313

DØ: LuminosityEvents vs. date

06/0

1

09/0

2

Data taking efficiency was far below expectations; improved a lot, e.g. a run from last week: 93.5% 40

15 Dec 02




1414

DØ: RunIIb Detector PlansNew silicon detector:• Single sided, barrels only• Installation takes 7

weeks (starting beginning of 2005)

• Inner (vertexing) layers 0, 1 axial, on carbon support

• Outer (tracking) layers 2-5 axial + stereo (tilted sensors)

• Prototype module essentially done

• Lots of experience from RunIIa silicon




1515

Physics: Analysis

Updated reconstruction software: Improved tracking efficiency, object identification, jet energy correction etc

Reconstruction farms in place for high luminosity

NIKHEF 2nd biggest MC provider:

107 events

1/0

2

12/0

2




1616

Physics: Analysis

Remote analysis possible, e.g. @ Amsterdam, Nijmegen:

• running local code installations, provided by standard code distribution system

• retrieving data from all other centers (which is, 99%, FNAL) transparently by “SAM”

• huge improvement to last year’s “500 users on one machine” situation




1717

Physics: Analysis Strategy

Topics of interest for NIKHEF: top, Higgs

Until there is enough luminosity: bread and butter physics, developing and using tools

• b jet tagging (leptons, lifetime, vertex), cross section

• Z b b (benchmark for Higgs search), cross section

Already now first top analyses:

• cross section t t all hadronic and t t e + jets




1818

Physics: Analysis Topics

NIKHEF PhD students’ work (physics!) at DØ

• Silke Duensing: ID (see the so far unseen at DØ)

• Paul Balm: exclusive b decay• Bram Wijngaarden: b jet search with lifetime

information• Onne Peters: b jet cross section measurement• Axel Naumann: Z b b cross section

measurement• Freya Blekman: tt all hadronic • Lukas Phaf: tt e + + jets• Cristina Galea




1919

Physics: Impact Parameter b Tag

Jets with associated muon

Courtesy of Bram WijngaardenGeneric jet sample

Track

Prim Vtx

ImpP

b quark




2020

Data

MC

Pythia

Physics: b Jet Cross Section

Courtesy of Onne Peters

+ jet cross section

PTRel for different

samples

b jet cross section from + jet sample

b /K c

Run 2 data20<ET

Jet<25GeVFit

MCPythia




2121

Physics: Z 2 Candidate

Courtesy of Silke Duensing

Muon + narrow had jet, both with tracksInv Mass 60GeV

p p Z + 2




2222

Top quark mass (GeV)

W m

ass

(GeV

)

2001

mt 2 GeVmW 15 MeV

Stand

ard

Mod

elSuper

sym

met

ry

Physics: Plans

2fb-1 – Measure top

mass ±3 GeV

– Measure W mass ± 15 MeV

– Directly exclude

mH = 115 GeV– SUSY Higgs

search @ large tan

– Constrain the CKM matrix




2323

6.5 fb-1 – 3 Higgs signal @ mH = 115 GeV; – exclude Higgs 115-125, 155-175 GeV– exclude much of SUSY Higgs parameter

space– possible discovery of SUSY in very large

fraction of minimal SUSY parameter space

11 fb-1

– 3 Higgs signal mH = 115-125, 155-175 GeV;

– exclude Higgs over whole range 115-175 GeV

– possible discovery of SUSY in larger fraction of parameter space

15 fb-1

– 5 Higgs signal @ mH = 115 GeV; – 3 Higgs signal 115-175 GeV

Physics: Plans

Each factor of two in luminosity yields a

significant increase in reach and lays the foundation for

the next steps




2424

DØ: Rumors…

Breaking news: Higgs has been seen

Strange properties: It’s not colorless!

Cheaper than expected…




2525

DØ: Summary And Future• Detector completed, running smoothly• Luminosity excellent progress in the past

year that serves as a solid platform for future progress

• First “real” physics results are coming in

• Main area of work now reconstruction, analysis




2626

Detector: Forward ProtonElastic scattering data

Scintillating fiber detector inside

t

-59m +33m0m

0




2727

Detector: Forward Preshower

Extensive forward coverage: 1.5 || 2.5

u,v stereo layers with 15k channels

Offline reconstruction using matched u, v clusters and E correlation




2828

Detector: Scintillating Fiber Tracker

Fully instrumented, performing well (layer eff >98%)Also used for track triggering on Level 1 (CTT)

status of dØ

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