Status Of D

1
Status Of DØ
2
Overview

• Detector
• Data
• Luminosity
• DAQ
• Physics

3
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 gt75
• gt50pb-1 available for Moriond

4
The DØ Detector

• New for RunII
• 2T solenoid
• silicon tracker
• Rebuilt
• central tracking
• part of calorimeter and muon system
• trigger system

5
Detector Silicon Tracker

• p-side pulse height
• 1 mip 25 counts
• Signal/Noise 12
• Layer efficiency 97

Layer 1,2 Bias Current
p-side pulse-height (ADC)

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

Bias Current
0.02
0.04
0.06
Integrated Lumi (fb-1)
6
Detector Tracking Performance
width 36 ?m ?(beam) 30 ?m ? ? 20 ?m
Survey-only alignment constants
first SMTalignment - it helps!
pT (GeV)

• KS ? ??

Significant improvement expected from alignment
with data in near future
7
Detector Calorimeter performance
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Detector Trigger, DAQ

• L1 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

9
Tevatron

• Luminosity major concern Tevatron and DØ DAQ
  performance in the beginning far below
  expectations (got little beam and didnt record
  events)
• Official lumi goal for RunIIa gt51031cm-2sec-1,
  integrated lumi of 2fb-1 actual limit believed
  to be 21032cm-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)

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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-gtMain Injector transfer optics
• Adjustment of tunes during low beta squeeze
• Modified injection helix in Tevatron
• Proton beam loading compensation in Main Injector
• Accumulator (stochastic) cooling upgrade
• Accumulator shot lattice
• Antiproton beam loading compensation in Main
  Injector
• Tevatron beam line tuner (BLT)
• Tevatron tune/coupling drift compensation
• Tevatron transverse dampers
• Beams division guy (1.15)10 4.0

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Tevatron Plans

• January 3.5 week summer shutdown used for
  maintenance and improvements

RunIIb prospects RD still going on, official
baselining in a few days (DØs Christmas
present)
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DØ Luminosity
Tevatron delivered luminosity in the beginning
below expectations now catching up
rapidly Reason why lumi is essential
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DØ Luminosity
Data taking efficiency was far below
expectations improved a lot, e.g. a run from
last week 93.5
Events vs. date
40
06/01
09/02
15 Dec 02
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DØ RunIIb Detector Plans

• New 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

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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
1/02
12/02
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Physics Analysis

• Remote analysis possible, e.g. _at_ 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 years 500 users on one
  machine situation

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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

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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

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Physics Impact Parameter b Tag
Track
ImpP
b quark
Prim Vtx
Jets with associated muon
Generic jet sample
Courtesy of Bram Wijngaarden
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Physics b Jet Cross Section
b jet cross section from ? jet sample
PTRel for different samples
Run 2 data 20ltETJetlt25GeV
Fit
b ??
MC Pythia
?/K ??
? jet cross section
c ??
Courtesy of Onne Peters
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Physics Z ? 2? Candidate
p p ? Z ? ? ?
? ? 2 ? ? ? ?
Muon narrow had jet, both with tracks Inv Mass
? 60GeV
Courtesy of Silke Duensing
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Physics Plans

• 2fb-1
• Measure top mass 3 GeV
• Measure W mass 15 MeV
• Directly exclude mH 115 GeV
• SUSY Higgs search _at_ large tan ?
• Constrain the CKM matrix

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Physics Plans

• 6.5 fb-1
• 3? Higgs signal _at_ 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 _at_ mH 115 GeV
• 3? Higgs signal 115-175 GeV

Each factor of two in luminosity yields a
significant increase in reach and lays the
foundation for the next steps
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DØ Rumors

• Breaking news Higgs has been seen
• Strange properties Its not colorless!
• Cheaper than expected

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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

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Detector Forward Proton
Elastic scattering data
x
0
t
Scintillating fiber detector inside
-59m
33m
0m
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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

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Detector Scintillating Fiber Tracker

• Fully instrumented, performing well (layer eff
  gt98)Also used for track triggering on Level 1
  (CTT)