The SiD Detector Concept

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The SiD Detector Concept SiD-UK
Meeting 07/September/2007 Oxford Marcel
Stanitzki STFC - Rutherford Appleton Laboratory
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The ILC environment

• e- and e collisions at vs 500 GeV.
• High luminosity? extremely small beams at
  interaction point beam height 5 nm, width
  500 nm.
• Leads to beamstrahlung
• Beamstrahlung photons interact with particles in
  the opposing bunch and generate ee- pairs.

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Physics at the ILC

• b/c-tagging with high purity/efficiency
• e.g. Higgs branching ratios
• Precision Tracking
• Recoil mass measurements
• Jet energy resolution
• Multi jet final states e.g. ttbar
• separation of WW/ZZ
• Forward region very important
• ILC physics becomes forward boosted at higher
  energies

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For example ...
Mbb (GeV)?
Mbb (GeV)?
ee- ? ZH ? qqbb _at_ 350GeV, 500fb-1 Mjj of two
b-jets for different jet energy resolution. ?
40 luminosity gain
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Detector Requirements

• Impact parameter resolution
• Momentum resolution
• Jet energy resolution goal
• Detector implications
• Calorimeter granularity
• Pixel size
• Material budget, central
• Material budget, forward

• Need factor 3 better than SLD
• Need factor 10 (3) better than LEP (CMS)?
• Need factor 2 better than ZEUS
• Detector implications
• Need factor 200 better than LHC
• Need factor 20 smaller than LHC
• Need factor 10 less than LHC
• Need factor gt100 less than LHC

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Particle Flow

• Classical LHC style calorimetry cannot
  delivered desired performance
• Need for better approach Particle Flow
  Algorithms (PFA)?
• Particle Flow has been done at LEP .. to some
  extend
• No detector has ever been designed for Particle
  Flow
• Integration of Algorithms and hardware early on
• PFA is the prime candidate to deliver desired
  energy resolution.
• New design paradigm
• Detector is viewed as single fully integrated
  system, not a collection of different
  subdetectors

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PFA in a nutshell
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SiD rationale

• A compact detector optimized for PFA
• integrated approach early on
• build on SLD experience
• Vertex detector (Silicon Pixel based)?
• All Silicon tracking
• low material budget in barrel and forward region
• robust against beam backgrounds
• Highly granular Calorimetry for PFA
• Calorimeter inside coil
• SiW for the ECAL
• Digital HCAL with RPC's

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SiD rationale cont'd

• 5 T Coil
• keeps detector compact
• suppress beam background
• allows smaller beam pipe
• Single bunch time stamping
• wherever feasible
• suppresses beam background
• robust reconstruction

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The SiD Detector Concept
ECAL
Vertex Detector
HCAL
Tracker
Solenoid
Flux Return and Muon chambers
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SiD Dimensions
Flux return/muon Rin 333 cm Rout 645 cm
Solenoid 5 T Rin 250 cm
PFA
HCAL Fe 34 layers Rin 138 cm
EMCAL Si/W 30 layers Rin 125 cm
Si
Si tracking 5 layers Rin 18 cm
Vertex detector 5 barrels, 4 disks Rin 1.4 cm
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The Vertex Detector

• 5 Barrels
• Rin 14 mm to Rout 60 mm
• 24-fold f segmentation
• 12.5 cm each
• All barrel layers same length
• 2 x 4 Forward Disks
• radius increases with Z
• Low material-low power design
• 0.1 X0

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The Tracker

• 5 layer Si-Tracker
• 5 barrel cylinders
• f readout only
• 10 cm z segmentation
• 5 forward double disks
• measure r and f
• Material budget 0.8 X0/layer

Layer 5
Layer 1
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Tracker Mechanics

• Sensor Tiles for barrel
• Kapton cables for signal routing
• Lightweight space frame

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The Si-W ECAL

• 30 layer Si-W
• 20/10 configuration
• 2.5 / 5 mm W
• 16 mm2 Si-Pads
• Shaped as hexagons
• 1300 m2 Si area
• KPIX Chip for readout
• bump-bondable
• 1024 channels
• time stamping
• 4 buffers per pad

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The HCAL

• Lot of technology choices
• Absorber
• Tungsten/Steel
• Readout
• Digital (RPC/GEM)?
• Analog (Scintillator SiPM)?
• High granularity necessary for PFA
• ECAL/HCAL integrated unit

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HCAL Status

• Digital Readout
• RPC/GEM
• 1 x 1 cm pad size
• Tested in testbeam
• Analog readout
• Scintillator tiles
• 3 x3 cm
• Si-PM as readout
• A lot of RD ahead

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The Coil

• Compact detector dictates high field
• 5 T field
• Comparison to CMS
• CMS I19500A / 2.6 GJ
• SiD I18000A / 1.4 GJ
• Coil design built on CMS experience
• Still highest field ever in HEP

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Muon System

• Baseline design
• Octagon design
• 48 layers of 5 cm steel absorbers
• Gap instrumentation for Muon ID
• Many technology choices
• Scintillator/RPC/GEMs
• Open question Tail catcher
• Punch-through
• requires different instrumentation
• position resolution needed
• lt 3cm

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Forward Region/MDI

• Measure
• Luminosity
• Energy
• Polarization
• MDI Integral part of SiD
• mechanics
• support
• placement of forward systems

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SiD Software framework

• Two main software packages
• Simulation is done by SLIC
• Based on GEANT4
• Detector configuration easily changed using XML
• Reconstruction/Analysis is done in org.lcsim
• Java based
• GUI available JAS3
• Data format is LCIO

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At a glance
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Software Comparison
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Integrated Tracking

• Studies using SiD full simulation
• Benchmark ttbar at vs 500 GeV
• Track seeding done by Vertex detector
• 3 hit patterns

Central Resolution
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Calorimeter Aided Tracking

• Calorimeter has tracking capabilities
• Use Calorimeter stubs
• outside-in tracking
• V0 reconstruction
• Powerful tool for long-lived particles

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SiD PFA work

• PFA template
• modular approach
• integrated in org.lcsim
• several algorithms
• Current Status
• advanced developer release
• cross-checks with Pandora
• not quite production-ready yet
• Opportunity to contribute !
• Comparing Algorithms is quite difficult

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Current Performance
All events, no cut Mean 88.43 GeV RMS 5.718
GeV RMS90 3.600 GeV 38.2 /sqrt(E) or sEjet
/Ejet5.8
Barrel events (cos(thetaQ) lt 1/sqrt(2))? Mean
89.10 GeV RMS 4.646 GeV RMS90 3.283 GeV 34.7
/sqrt(E) or sEjet /Ejet5.2
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Benchmarking SiD

• Effort is starting now
• Software is getting ready for users
• Trying to answer a lot of questions
• Calorimeter (pad size, radius, depth)?
• Tracking
• Radius
• Field
• How well does SiD do on physics ?

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SiD in comparison
Only considering PFA-Detectors here Numbers form
Detector Outline Documents
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Some comments

• All Detector Concepts are evolving
• Several versions of each concept with differences
  in
• Radii
• Calorimeter depth
• Calorimeter Material
• Analog/Digital
• Tracker layout
• ....

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Costing SiD

• Attempt to understand
• Cost drivers
• Critical systems
• A coarse attempt
• Gives a first idea
• Costing done in DOE style

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Conclusion

• It is a great time to get involved in SiD
• Still a lot of RD to do
• SiD is a robust design for ILC physics
• Thanks to J. Brau, P. Dauncey, M. Demarteau, J.
  Jaros, S. McGill, M. Tyndel, H. Weerts, L. Xia
  for input and comments

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BACKUP
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SiD PFA timeline