Status report from the Atlas LNF group

1
Status report from the Atlas LNF group

• Bellisario Esposito
• Outline
• LNF partecipation in Atlas
• Detector activity and status
• Preparation to the Analysis of Data
• Computing
• Personnel
• Conclusions

2
Atlas LNF group

• Researchers
• Permanent Antonelli M, Bilokon H, Cerutti F,
  Chiarella V, Curatolo M, Esposito B,
• Ferrer ML, Giovannella S, Laurelli
  P,Maccarrone G, Martini A, Miscetti S, Nicoletti
  G, Sansoni A
• Temporary Beretta M, Gatti C, Wen Mei,Vilucchi
  E
• (Barone M, Kordas K,
  Ventura S)
• Technicians
• Permanent Capitolo E, Pileggi G, Ponzio B,
  Russo V
• Temporary Vassilieva T
• SPAS Service Capoccia C, Cerioni S
  (1fte)
• Computing Center Maselli D, Soprano C (1fte)

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LNF partecipation in Atlas

• Interest in the Physics with muon signature
• Detector contribution Muon precision tracking
  chambers
• RD, final design, series production and
  QA/QC Facilities,
• construction, commissioning
• Contribution to the Trigger/DAQ software
• Test beam and cosmic test station at LNF
• Data Analysis and simulation studies
• Computing

4
BML MDT chambers

• 94 BML area600 m2 6 layers of tubes
  28000 tubes
• Wire positioning specification

Measured Wire position fluctuation with respect
to the nominal grid.
5
Series Production and QA/QC Facilities
6
Detector Activity and Status

• All 94 chambers installed in Atlas
• Positioning and sector commissioning going on
• (LNF Physicists, Engineers and Technicians
  strongly involved)
• Commissioning of Trigger/DAQ

7
Preparation to the Data Analysis

• Understanding the detector
• test beam , cosmic rays, commissioning in
  the pit,
• performance studies with data and MC
• Methods for in-situ calibration with known
  physics events
• (as Z? µµ, J/Psi?µµ ..) (Note CSC)
• Developing analysis algorithms
• Signal/Background separation, Integrated
  Luminosity
• Trigger strategy, Detector performance,
  Signal significance
• Standard Physics, New Physics, Early Physics
• Higgs (Note CSC), Supersimmetric Higgs
  (Note CSC)
• New Z Bosons, Lepton Flavour violation
• Z , W production
• J/Psi, Y production
• Getting ready with computing resources

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Muon Spectrometer in-situ calibration

• Absolute Momentum Scale
• Alignement, B-field, material
• PcorK/(1/Pms ds)?E dE
• K,ds,dE depend on eta,phi
• to be determined by fitting the known Z mass
  profile
• Trigger and Track Efficiency
• 1 µ required 1 ID track Z mass
• Check if 2nd track seen in the muon detector

9
MC samples for scale calibration and efficiency
determination

• The effects of misalignment, tilted B field, and
  wrong knowledge of detector material have to be
  tested.
• The officially produced raw MC files (RDOs)
  contain events simulated with misalbmat
  geometry (including all three effects).
• On the Frascati Tier-2 the files were copied and
  reconstructed using 3 different geometries (from
  to ideal to misalbmat).

3500 RDOs for the Z??? sample and 1000 RDOs for
the J/? sample reconstructed 50 events
per RDO (each RDO is about 2.4 MB/evt 120
MB) The reconstruction time is about 24 s/evt,
for a total recontruction time of 24x50x31 h per
input file (for 3 different geometry conditions).
With 29 CPUs it takes (full efficiency, free
slots ...) 1 week to complete the reconstruction.
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Local event production
bb A/H/h bb ??-

• Signal bb A/H/h bb ??-
• Range 15 tan ? 50 95 GeV mA 125
  GeV 5x8 points.
• Backgrounds
• bbZ bb ??- () , tt bb ??- ??-, ZZ
  bb ??-
• ) can be estimated from Z ee-
• MC events 10 M (150k jobs)

t-3µ
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Track efficiency from J/?
Sample of prompt J/???? events, simulated with pT
cut of 6 and 4 GeV on the two muons.
50,000 events (corresponding to L 5
pb-1) reconstructed. Event selection an
identified muon (IDMS).
Muon
tag an ID track with invariant mass with the
identified muon close to MJPsi. Tracking
efficiency the ratio of found muon tracks
divided by the number of tagged muons. The
comparison of measured from data and true-MC
efficiency is done for several slices in the pT-?
plane, and for different cuts on the ?2 of the
tagged track.
A good agreement is found for all slices and
for different cuts.
The study of trigger and background
biases is underway.
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Momentum scale from Z mass fitting
MisalbMat

• 15 k events of Z ? ??
• fit reconstructed Z mass
• Free fit parameters
• Momentum scales in Barrel
• and Ecap regions (???).
• folding the generated
• P spectra with MC resolution

M(??) (GeV)
??????????? (4 ? 14) ?10 -4 ??????????? (1 ? 13)
?10 -4
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Search for extra vector boson Z

• Preliminary study based on MC sample Z(SSM)???
  (Sequential Standard Model)
• 1000 events M(Z)1 TeV (2 fb-1) 1000
  events M(Z)2 TeV (40 fb-1)
• 95 of background comes from pp?? ? Z???
  (included in the simulation).
• Event selection two tracks in the muon
  spectrometer of opposite charge
• Loose cuts on track ?2 (selection
  efficiency 80)

• Studies on-going
• discovery potential for masses up to few TeV and
  for different models (cross sections)
• effect of misalignment and impact on discovery
• determination of Z spin through AFB measurement

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bb A/H/h bb ??-
Range studied 15 tan ?? 50 95 GeV mA
125 GeV (5x8 points)
Discovery potential (in the MSSM mh-max scenario)
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LFV decay ??????
Forbidden in the SM In models beyond SM (MSSM,
Non universal Z, SMseesaw, mSugra . )
expected BR ranging from 10-7 - 10-10 Best
limits so far from the B-factories 90 C.L. Assuming BR2x10-7 and ?(W???) 20.4
?0.7 nb 40 events expected in 10 fb-1
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Computing

• ATLAS Computing Model
• Tier0, Tier1, Tier2 are the central, regional and
  local
• computing resources
• Centralized data processing at Tier0, Tier1
• Simulation and analysis at Tier2
• ATLAS-Italy Tier organisation
• 1 Tier1 (CNAF)
• 4 Tier2 (Roma1, Napoli,Milano, LNF)
• 1Tier2 additional (Bologna) at CNAF also
  considered
• INFN decisions
• 2 Tier2 (Roma1,Napoli) approved by INFN up to now
• The other sites (Milano, LNF) required to keep
  alive and active in order to be discussed later
  on
• Important ingredient in the INFN decisions is
  the consideration of the
• available infrastructure and man-power

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LNF proto Tier2

• At LNF installed and successfully operating a
  proto Tier2 ( 41 kSI2k 16TB
  )
• Personnel
• 2 (1fte) Computing center
• 4 (3fte) from ATLAS

• Activity
• Atlas CSC production
• Local production
• Analysis

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Tier-2 development plan

• Resources available are adequate for the present
  phase
• ( CSC event production , LHC not yet running)
• A large increase is foreseen in the course of
  next years
• Present INFN Referees plan for Atlas Tier-2
• Year 2006 2007 2008
  2009 2010
• CPU (kSi2k) 400 400 1519 2682
  5009
• Disk (TB) 90 165 727
  1427 2555
• The computing resources indicated are the total
  to be considered for all
• the Tier-2 ( each of the Tier-2 about ¼
  of the total )
• Infrastructural upgrade of the computing center
  at LNF is necessary to
• host the final configuration of computing
  resources envisaged

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Computing center building
Infrastructure needed for the Tier2 at LNF
Tier 2
A detailed design of the Power system and the
Conditioning system has been made. Some upgrade
of the computing center infrastructure is needed
anyway independently of the Tier2. The additional
cost necessary in order to make the infracture
adequate for the Tier2 is 150KEuro.
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Personnel (1)

• Technical staff
• Group technicians 4
• Temporary contracts 1
  4(production)
• Visitors
  2-4(production)
• Design Office Engineers 2 1(project)
• Workshop
• Electronic workshop
• Computing center 2 (1fte)

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Personnel (2)

• Physicists staff 05
  06 07
• Permanent (fte)
  11.4 11.2 12.1
• Temporary
• Fellows
  1 0
  0
• PhD Student
  1 1 0
  
• Post-Doc
  2 1 0
  
• Temporary contract (art 23)
  3 3 3
• Temporary Collaboration (art 2222)
  1 1 1

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Conclusions

• The LNF group in the many years (17)devoted to
  the Atlas experiment has given important
  contribution to the realization of the Atlas
  detector, thanks to the support of the Laboratory
  and to the expertise and the ingenuity of the
  staff
• The final goal of doing Physics at a new energy
  frontier, which motivated the Laboratory and
  each one of the participants to get involved in
  the Atlas experiment, is approaching and we are
  getting ready for it. For that to be a success
  the support of the Laboratory is needed in terms
  of man power and infrastructure.