Calorimetry and Muons

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Calorimetry and Muons Summary Talk
Andy White University of Texas at
Arlington LCWS05, SLAC March 22, 2005
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Overview of talk

• Physics processes driving calorimetry and muon
  systems designs
• Calorimeter system design
• Different approaches to LC calorimetry
• Integrated detector design issues
• Electromagnetic Calorimeter Development
• Hadron Calorimeter Development
• Muon system/tail-catcher
• Timescales - where we go from here!

Note Simulation and algorithm work reviewed in
next talk.
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Physics examples driving calorimeter and muon
system design
Muon
Jet energy resolution
From M.Battaglia Large Detector Meeting/Paris
2005
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Physics examples driving calorimeter design
Missing mass peak or bbar jets
Higgs production e.g. e e- -gt Z h
separate from WW, ZZ (in all jet modes) Higgs
couplings e.g. - gtth from e e- -gt
tth -gt WWbbbb -gt qqqqbbbb ! - ghhh from e e-
-gt Zhh Higgs branching ratios h -gt bb, WW, cc,
gg, ?? Strong WW scattering separation of
ee- -gt ??WW -gt ??qqqq ee- -gt ??ZZ -gt
??qqqq and ee- -gt ??tt
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Physics examples driving calorimeter design

• All of these critical physics studies demand
• ? Efficient jet separation and reconstruction
• ? Excellent jet energy resolution
• ? Excellent jet-jet mass resolution
• jet flavor tagging
• Plus We need very good forward calorimetry for
  e.g. SUSY selectron studies,
• and ability to find/reconstruct photons from
  secondary vertices e.g. from long-lived NLSP -gt
  ?G

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Calorimeter system/overall detector design

• Initially two general approaches
• Large inner calorimeter radius -gt achieve good
  separation of e, ?, charged hadrons, jets,
• Matches well with having a large tracking
  volume with many measurements, good momentum
  resolution (BR2) with moderate magnetic field, B
  2-3T
• But calorimeter and muon systems become
  large and potentially very expensive
• Howevermay allow a traditional approach to
  calorimeter technology(s).
• EXAMPLES Large Detector, GLD

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Large Detector
Detectors with large inner calorimeter radius
GLD
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Calorimeter system/overall detector design
(2) Compact detector reduced inner calorimeter
radius. Use Si/W for the ECal -gt excellent
resolution/separation. Constrain the cost by
limiting the size of the calorimeter (and muon)
system. This then requires a compact tracking
system -gt Silicon only with very precise (10?m)
point measurement. Also demands a calorimeter
technology offering fine granularity -gt
restriction of technology choice ?? To restore
BR2, boost B -gt 5T (stored energy,
forces?) EXAMPLE SiD
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Compact detector
SiD
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How big ??

• Area of EM CAL (Barrel Endcap)
• SD 40 m2 / layer
• TESLA 80 m2 / layer
• LD 100 m2 / layer
• (JLC 130 m2 / layer)

Very large number of channels for 0.5x0.5cm2
cell size!
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Can we use a traditional approach to
calorimetry? (using only energy measurements
based on the calorimeter systems)
30/?E
60/?E
Target region for jet energy resolution
H. Videau
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Results from traditional calorimeter systems

• Equalized EM and HAD responses (compensation)
• Optimized sampling fractions
• EXAMPLES
• ZEUS - Uranium/Scintillator
• Single hadrons 35/?E ? 1
• Electrons 17/?E ? 1
• Jets 50/?E
• D0 Uranium/Liquid Argon
• Single hadrons 50/?E ? 4
• Jets 80/?E
• Clearly a significant improvement is needed for
  LC.

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A possible approach to enhancing traditional
calorimetry
The DREAM (Dual REAout Module)project high
resolution hadron calorimetry
Use quartz fibers to sample e.m. component
(only!), in combination with scintillating fibers
Structure
How to configure for a LC detector?
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The Energy Flow Approach
Energy Flow approach holds promise of required
solution and has been used in other experiments
effectively but still remains to be proved for
the Linear Collider! -gt Use tracker to measure Pt
of dominant, charged particle energy
contributions in jets photons measured in
ECal. -gt Need efficient separation of different
types of energy deposition throughout calorimeter
system -gt Energy measurement of only the
relatively small neutral hadron contribution
de-emphasizes intrinsic energy resolution, but
highlights need for very efficient pattern
recognition in calorimeter. -gt Measure (or veto)
energy leakage from calorimeter through coil into
muon system with tail-catcher.
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Dont underestimate the complexity!
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What is a jet?
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• Note - It is popular to quote the averages of
  these distributions, however
• there are wide variations, and we will have to
  develop efficient procedures for events with e.g.

25 neutral hadrons, 40 EM (all photons?), 35
Charged hadrons
gt Challenging task to find all neutral clusters
(and not mis-associate them with a track!)
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Integrated Detector Design
Muon system/ tail catcher
Tracking system
VXD tag b,c jets
HAD Cal
EM Cal
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Integrated Detector Design
So now we must consider the detector as a whole.
The tracker not only provides excellent momentum
resolution (certainly good enough for replacing
cluster energies in the calorimeter with track
momenta), but also must - efficiently find all
the charged tracks
Any missed charged tracks will result in the
corresponding energy clusters in the calorimeter
being measured with lower energy resolution and a
potentially larger confusion term.
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Integrated Detector Design

• provide excellent two track resolution for
  correct track/energy cluster association
• gt tracker outer radius/magnetic field size
  implications for e.m. shower separation/Moliere
  radius in ECal.
• Different technologies for the ECal and HCal ??
• - do we lose by not having the same technology?
• - compensation is the need for this
  completely overcome by using the energy flow
  approach?

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Integrated Detector Design

• Services for Vertex Detector and Tracker should
  not cause large penetrations, spaces, or dead
  material within the calorimeter system
  implications for inner systems design.
• Calorimeters should provide excellent MIP
  identification for muon tracking between the
  tracker and the muon system itself. High
  granularity digital calorimeters should naturally
  provide this but what is the granularity
  requirement?
• We must be able to find/track low energy ( lt 3.5
  GeV) muons completely contained inside the
  calorimeter.

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Calorimeter System Design
? Identify and measure each jet energy component
as well as possible Following charged particles
through calorimeter demands high granularity
Two options explored in detail (1) Analog ECal
Analog HCal - for HCal cost of system for
required granularity? (2) Analog ECal Digital
HCal - high granularity suggests a digital HCal
solution - resolution (for residual
neutral energy) of a purely digital
calorimeter??
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Calorimeter Technologies
Electromagnetic Calorimeter
Physics requirements emphasize segmentation/granul
arity (transverse AND longitudinal) over
intrinsic energy resolution. Localization of e.m.
showers and e.m./hadron separation -gt dense
(small X0) ECal with fine segmentation. Moliere
radius -gt O(1 cm.) Transverse segmentation ?
Moliere radius Charged/e.m. separation -gt fine
transverse segmentation (first layers of
ECal). Tracking charged particles through ECal -gt
fine longitudinal segmentation and high MIP
efficiency. Excellent photon direction
determination (e.g. GMSB) Keep the cost (Si)
under control!
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SLAC-Oregon Si-W ECal RD
Readout development M.Breidenbach
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CALICE Si/W Electromagnetic Calorimeter
Wafers Russia/MSU and Prague
PCB LAL design, production Korea/KNU
New design for ECal active gap -gt 40 reduction
to 1.75m, Rm 1.4cm
Evolution of FE chip FLC_PHY3 -gt FLC_PHY4 -gt
FLC_TECH1
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CALICE-ECal - results
Move (completed) module to Fermilab test beam
late 2005
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ECal work in Asia
Si/W ECal prototype from Korea
Rt a layer / tungsten 15.0/3.5 4.8
(CALICE 2) Eff. Rm 9mm (1 Rt)
52mm Total 20 layers 20 X0, 30cm thick 19
layers of shower sampling
Results from CERN beam tests 2004 29/?E
(vs. 18/?E for GEANT4)
S/N 5.2
Fit curve of 29/vE
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ECal work in Asia (Japan-Korea-Russia)
Fine granularity Pb-Scintillator with
strips/small tiles and SiPM
Previous Pb/Scint module with MAPMT readout
Study covering
New GLD ECal design
ECal test at DESY in 2006?
YAG - 2?m precision
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Scintillator/W U. Colorado
Half-cell tile offset geometry
Electronics development is being pursued with
industry
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Hybrid Ecal Scintillator/W with Si layers
LC-CAL (INFN)

• 45 layers
• 25 25 0.3 cm3 Pb
• 25 25 0.3 cm3 Scint. 25 cells 5 5 cm2
• 3 planes 252 .9 .9 cm2 Si Pads at 2, 6, 12
  X0

Low energy data (BTF) confirmed at high energy
!!!
11.1??E
?3.27 mm

• The LCcal prototype has been built and fully
  tested.
• Energy and position resolution as expected
• ?E/E 11.-11.5 /?E, ?pos 2 mm (_at_ 30
  GeV)
• Light uniformity acceptable.
• e/? rejection very good ( lt10-3)

Si L3
Si L2
Si L1
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Calorimeter Technologies
Hadron Calorimeter

• Physics requirements emphasize segmentation/granul
  arity (transverse AND longitudinal) over
  intrinsic energy resolution.
• - Depth ? 4? (not including ECal 1?)
• Assuming EFlow
• - sufficient segmentation to allow efficient
  charged particle tracking.
• - for digital approach sufficiently fine
  segmentation to give linear energy vs. hits
  relation
• - efficient MIP detection
• - intrinsic, single (neutral) hadron energy
  resolution must not degrade jet energy
  resolution.

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Hadron Calorimeter CALICE/analog
Minical results from electron test beam
SiPM
Full 1m3 prototype stack with SiPM readout.
Goal is for Fermilab test beam exposure in Spring
2006

• APD chips from Silicon Sensor used
• AD 1100-8, Ø 1.1 mm, Ubias 160 V

APD
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Hadron Calorimeter CALICE/analog
Cassette production
Support structure being provided by DESY for test
beam at Fermilab
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Hadron Calorimeter CALICE/digital
(1) Gas Electron Multiplier (GEM) based DHCAL
500 channel/5-layer test mid -05 30x30cm2 foils
Recent results efficiency measurements confirm
simulation results, 95 for 40mV threshold.
Multiplicity 1.27 for 95 efficiency. Next 1m x
30cm foil production in preparation for 1m3 stack
assembly. Joint development of ASIC with RPC
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Hadron Calorimeter CALICE/digital
(2) Resistive Plate Chamber-based DHCAL
(On-board amplifiers)
Pad array
Mylar sheet
Resistive paint
1.1mm Glass sheet
1.2mm gas gap
GND
1.1mm Glass sheet
Resistive paint
-HV
Mylar sheet
Aluminum foil
Low noise
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Muon System/Tail Catcher

• Muon identification/measurement essential for LC
  physics program.
• Role(s) of muon system/tail catcher
• -gt Identify high Pt muons exiting
  calorimeter/coil. Buthow much can we do with
  calorimeter alone?
• -gt ? Contribute to muon Pt measurement
  ? Poor hit position resolution, but long lever
  arm
• -gt Measure the last pieces of high energy
  hadron showers penetrating through the coil
  but, this is really measuring the tail of the
  tail.
• -gt ? Identify possible long-lived particles
  from interactions?

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Muon Technologies
Scintillator-based muon system development
U.S. Collaboration
Extruded scintillator strips with wavelength
shifting fibers.
Readout Multi-anode PMTs
GOAL 2.5m x 1.25m planes for Fermilab test beam
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Muon Technologies
European CaPiRe Collaboration
TB _at_ Frascati
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TCMT CALICE/NIU
Extrusion
Cassette
SiPM location
Goal Test Beam Fermilab/2005
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Timeline of Beam Tests
CALICE SiW ECAL
OTHER ECALs
CALICE TILE HCALTCMT
CALICE DHCALs and others
ILCD RD, calibration
Combined CALICE TILE
Combined Calorimeters
m, tracking, MDI, etc
PFA and shower library Related Data Taking
Phase I Detector RD, PFA development, Tech.
Choice
Phase II
Phase 0 Prep.
From Jae Yu
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Timescales for LC Calorimeter and Muon development
We have maybe 3-5 years to build, test, and
understand, calorimeter and muon technologies for
the Linear Collider. By understand I mean that
the cycle of testing, data analysis, re-testing
etc. should have converged to the point at which
we can reliably design calorimeter and muon
systems from a secure knowledge base. For the
calorimeter, this means having trusted Monte
Carlo simulations of technologies at
unprecedented small distance scales (1cm),
well-understood energy cut-offs, and
demonstrated, efficient, complete energy flow
algorithms. Since the first modules are only now
being built, 3-5 years is not an over-estimate to
accomplish these tasks! See talk by Jae Yu for
Test Beam details
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Window for Detector RD
2004
2005
2006
2007
2008
2009
2010
GDE (Design)
(Construction)
Technology Choice
Acc.
CDR
TDR
Start Global Lab.
Detector Outline Documents
CDRs
LOIs
Det.
Done!
Detector RD Panel
Collaboration Forming
RD Phase
Detector
Construction
Tevatron
SLAC B
HERA
LHC
T2K
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Comment on RD efforts

• It is clear that there are a number of
  parallel/overlapping RD efforts.
• This was inevitable, and desirable, in the early
  LC RD period.
• RD funding is generally limited we must make
  optimal use of those resources we have.
• A World Wide Study RD panel has been formed.
• Each detector concept will survey RD activity,
  needs
• -gt Hopefully this will provide a basis for more
  efficient use of limited RD resources

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From K.Kawagoe _at_ ACFA 07
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CONCLUSIONS

• A vigorous program of Linear Collider
  calorimetry and muon/tail catcher development is
  underway !
• Many results from prototypes but we should
  avoid too much duplication.
• A lot of work has been done with very limited
  detector RD budgets.
• It is critical to carry out an RD survey and
  ensure that Detector RD proceeds in a timely
  manner alongside Accelerator RD.
• This is particularly critical for U.S.-based
  calorimeter development which faces significant
  financial hurdles, and a long test beam program!