Current limitations and prospects for future results

1
Current limitations and prospects for future
results

• Common problems/issues
• Physics related problems
• Object-ID related problems
• Room for improvement
• Results expected for summer

2
General
We have much better results with p14 data. Thanks
to all who worked on p14 so hard!

• Better understanding of all objects
• Object identification criteria (jets, missing
  ET, electrons, muons, photons, tracking, primary
  vertex) are better optimized for physics
  analyses compared to p13 version
• While systematic errors on object IDs (e.g. JES,
  luminosity) are still big, they are smaller
  compared to p13 version
• Luminosity calculations centralized
• Gained from trigger optimization

3
Common problems

• Lack of manpower why?! We have 700 members in
  our collaboration, and every group in the
  experiment needs more people!
• Late data arrival
• a lot of continuous work to put everything
  together in D0reco
• MC production insufficient statistics
• for many background studies
• for systematic checks (fragmentation models,
  event modeling)
• Computing resources overloaded needed to
  reprocess/analyze data

4
General physics related problems

• Late object-ID certification
• depletion of manpower with data arrival
• little discussion with algorithms groups on final
  choice of object ID in physics analyses
• A lot of duplicated efforts in physics groups
• trigger turn-on curves
• high-pT lepton efficiency measurements

5
Limitations for physics analyses

• Jet ID/JES (WZ, Higgs, NP, QCD)
• big error on data/MC JES corrections (especially
  for high ?, pT of jets)
• need JES for low energies of jets
• need JES as a function of EM fraction
• jet pT resolution much worse compared to Run I
• non-uniform response of calorimeter in ? has to
  be understood
• with current calorimeter resolution lose a lot of
  statistical power from W sample

Even if we reduce JES error to Run I level, still
it will remain the source of largest systematic
error.
6
Limitations for physics analyses

• Electron/Photon ID (WZ, Higgs, NP, HF)
• need certified performance for photons with pT ?1
  GeV
• fix ?-dependence of calorimeter response
• MET (WZ, NP)
• need to understand unclustered energy
• Data Processing (all groups)
• Many skims are large (bMU, some Higgs skims,
  ?-in-jet B-ID) difficult to analyze/reprocess
  them with improved object IDs
• Data quality
• to be continuously improved

7
Limitations for physics analyses

• Tracking/Vertexing (WZ, Higgs, NP, HF, b-id)
• reconstruction inefficiency for high-pT
  electrons
• no work on bremsstrahlung
• charge mis-measurement different between MC and
  data
• better understanding of pT resolution for high-pT
  tracks
• vertex/beamspot-constraint refit of tracks
• inefficiency in tracking in jets
• reconstruction inefficiency for low-pT tracks and
  tracks with big DCA with standard reconstruction
  - need reprocess big samples with extended
  tracking
• fix material and magnetic field in reco to get
  masses right

8
Limitations on limitations general object ID
problems
Situation should be better for summer conferences
since reco version is stable and we do not expect
big delays with data, have time to attack
problems at lower level
9
Room for improvement

• JES have detailed plan on how to improve JES
  error, specifically showering uncertainty.
• Electron/photon ID plan to use CPS information
  (was lost during the first pass of TMB fixing)
• MET upgrade MissingET package, all tools to
  minimize the data rejection and to analyze
  reasons are in place
• Muon a lot of useful work is done already by
  rather isolated groups of people need to
  improve the coordination of efforts
• Tracking/vertexing have started material,
  post-shutdown alignment studies, working on
  improvement of the primary vertex reconstruction.

10
Actions for improvement
February Establish 90 running efficiency Add
hits to P14 TMB Certify
reprocessing including tracking using new TMB
March MC submission automated using RUNJOB,
SAM-GRID, and RTE Automate data
quality using P14 RECOCERT 210
pb-1 available for analysis with T42 (P14 RECO)
New material and alignment in RECO
/ simulation test release April STT fully
commissioned New photon ID in RECO test
release Submission of first papers
with 210 pb-1 May FPD detector and
trigger fully commissioned
Significantly reduce bad or questionable
luminosity blocks. Establish
capability to process 50M real data events / week
June 300 pb-1 available for analysis (P14
RECO) D0mino reduced to 64
processors Remote reconstruction available
P17 on farms July Trigger Filter
Version 14 running on-line
11
Prospects for future results

• Top group.
• Summer
• improve precision of ttbar production cross
  section measurement ? both topological and
  b-tagging
• single top
• top mass
• W helicity
• top decay studies
• ttbar resonances
• top pT spectrum

• New Phenomena
• Extra dimensions
• Dilepton resonances
• 1st and 2nd generations of LQ
• single LQ production
• LQ in the ? ? jj channel
• GMSB in ??MET channel
• SUSY trileptons
• RPV
• Stop in e? channel
• Stop/sbottom
• Squarks/gluinos
• Monojets

12
Prospects for future results

• WZ group
• Summer
• WZ trileptons
• Direct measurement of W width
• Lepton charge asymmetry
• Studies of Z production properties

• Higgs group
• W/Z dijet/bb cross section measurements
• WW? dileptons cross-section measurements
• H ? WW ? dileptons limit
• Doubly charged Higgs decaying into 4 leptons
• bh/bbh (?bb) analysis
• H???

13
Prospects for future results

• HF group
• Summer
• Bd mixing
• Charmonium production
• Limits on Bs???
• Branching fractions for Bd ?D??
• B signal

• QCD group
• Inclusive jet pT spectrum production
• Dijet mass cross-section measurements
• ?? between jets
• Dijet angular distribution
• High pT b-jets
• Diffractive Z
• Diffractive jets using FPD.

14
Summary

• Significant improvement in understanding data
• A lot of impressive physics results with current
  data
• For further improvements, our list-to-do is well
  defined
• It is not too big
• Need dedicated people to accomplish it
• Better organization/communication between
  algorithms/physics group
• Summer will bring us even more and better physics
  results