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

Calorimetry and Muons
Summary Talk
Andy White
University of Texas at Arlington
LCWS05, SLAC
March 22, 2005
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.
Physics examples driving calorimeter
and muon system design
Jet energy resolution
Muon
From M.Battaglia – Large Detector Meeting/Paris 2005
Physics examples driving calorimeter
design
Higgs production e.g.
e+ e- -> Z h
Missing mass peak
or bbar jets
separate from WW, ZZ (in all jet modes)
Higgs couplings e.g.
- gtth from e+ e- -> tth -> WWbbbb -> qqqqbbbb !
- ghhh from e+ e- -> Zhh
Higgs branching ratios h -> bb, WW*, cc, gg, 
Strong WW scattering: separation of
e+e- -> WW -> qqqq
e+e- -> ZZ -> qqqq
and e+e- -> tt
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 -> G
Calorimeter system/overall detector design
Initially two general approaches:
(1) Large inner calorimeter radius -> 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…
However…may allow a “traditional” approach to
calorimeter technology(s).
EXAMPLES: Large Detector, GLD
Large Detector
Detectors with large
inner calorimeter radius
GLD
Calorimeter system/overall detector design
(2) Compact detector – reduced inner calorimeter radius.
Use Si/W for the ECal -> excellent resolution/separation.
Constrain the cost by limiting the size of the calorimeter
(and muon) system.
This then requires a compact tracking system -> Silicon only
with very precise (~10m) point measurement.
Also demands a calorimeter technology offering fine
granularity -> restriction of technology choice ??
To restore BR2, boost B -> 5T (stored energy, forces?)
EXAMPLE: SiD
SiD
Compact
detector
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!
Can we use a “traditional” approach to calorimetry?
(using only energy measurements based on the
calorimeter systems)
60%/E
H. Videau
30%/E
Target region for jet
energy resolution
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.
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?
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!
-> Use tracker to measure Pt of dominant, charged
particle energy contributions in jets; photons measured in
ECal.
-> Need efficient separation of different types of energy
deposition throughout calorimeter system
-> 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.
-> Measure (or veto) energy leakage from calorimeter
through coil into muon system with “tail-catcher”.
Don’t underestimate the complexity!
What is a jet?
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
> Challenging task to find all neutral clusters (and not
mis-associate them with a track!)
Integrated Detector Design
VXD
tag b,c
jets
Tracking
system
EM Cal
HAD Cal
Muon
system/
tail
catcher
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.
Integrated Detector Design
- provide excellent two track resolution for correct
track/energy cluster association
-> 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?
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 ( < 3.5 GeV)
muons completely contained inside the calorimeter.
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??
Calorimeter Technologies
Electromagnetic Calorimeter
Physics requirements emphasize segmentation/granularity
(transverse AND longitudinal) over intrinsic energy resolution.
Localization of e.m. showers and e.m./hadron separation
dense (small X0) ECal with fine segmentation.
->
Moliere radius -> O(1 cm.)
Transverse segmentation  Moliere radius
Charged/e.m. separation -> fine transverse segmentation (first
layers of ECal).
Tracking charged particles through ECal -> fine longitudinal
segmentation and high MIP efficiency.
Excellent photon direction determination (e.g. GMSB)
Keep the cost (Si) under control!
SLAC-Oregon Si-W ECal R&D
Readout development – M.Breidenbach
CALICE – Si/W Electromagnetic Calorimeter
Wafers:
Russia/MSU
and Prague
PCB: LAL design,
production –
Korea/KNU
New design for ECal active gap -> 40%
reduction to 1.75m, Rm = 1.4cm
Evolution of FE chip: FLC_PHY3 -> FLC_PHY4 -> FLC_TECH1
CALICE-ECal - results
Move (completed) module to Fermilab test beam late 2005
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%/√E
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
Laser hitting area
(9 pixels)
New GLD ECal
design
ECal test at DESY in 2006?
YAG - 2m precision
Scintillator/W – U. Colorado
Half-cell tile offset geometry
Electronics development is being
pursued with industry
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
Si L3
Si L2
Si L1
e-
•
•
•
•
The LCcal prototype has been built and fully tested.
Energy and position resolution as expected:
E/E ~11.-11.5% /E, pos ~2 mm (@ 30 GeV)
Light uniformity acceptable.
e/ rejection very good ( <10-3)
Calorimeter Technologies
Hadron Calorimeter
Physics requirements emphasize segmentation/granularity
(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.
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
APD
chips from Silicon Sensor used
AD
1100-8, Ø 1.1 mm, Ubias~ 160 V
Hadron Calorimeter – CALICE/analog
Cassette production
Support structure being
provided by DESY for test
beam at Fermilab
Hadron Calorimeter – CALICE/digital
(1) Gas Electron Multiplier (GEM) – based DHCAL
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
500 channel/5layer test mid -’05
30x30cm2 foils
Hadron Calorimeter – CALICE/digital
(2) Resistive Plate Chamber-based DHCAL
Mylar sheet
Resistive paint
1.2mm gas gap
Resistive paint
Mylar sheet
(On-board amplifiers)
Pad array
1.1mm Glass sheet
1.1mm Glass sheet
GND
-HV
Aluminum foil
Tests
Results
Charge
Avalanche mode ~0.1 ÷ 5 pC
Streamer mode 5 ÷ 100 pC
Efficiency
Greater than 95 %
Drops to zero at spacer
Streamer fraction
Plateau of several 100 V where
efficiency > 95% and
streamer fraction < few percent
1 – gas gap versus 2 – gas gap
Larger Q with 1 – gas gap
Similar efficiency
Noise rate
Small ~0.1 – 0.2 Hz/cm2
Different gases
Best: Freon:IB:SF6 = 94.5:5:0.5
Low noise
Muon System/Tail Catcher
- Muon identification/measurement essential for LC
physics program.
- Role(s) of muon system/tail catcher:
-> Identify high Pt muons exiting calorimeter/coil.
But…how much can we do with calorimeter alone?
-> ? Contribute to muon Pt measurement ? Poor
hit position resolution, but long lever arm…
-> Measure the last pieces of high energy hadron
showers penetrating through the coil – but,
this is really measuring the “tail of the tail”.
-> ? Identify possible long-lived particles from
interactions?
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
Muon Technologies
European – CaPiRe Collaboration
TB @ Frascati
TCMT – CALICE/NIU
Extrusion
Cassette
SiPM
location
Goal: Test Beam
Fermilab/2005
Timeline of Beam Tests
2005
2006
2007
2008
2009
>2009
CALICE SiW ECAL
OTHER ECALs
CALICE TILE
HCAL+TCMT
CALICE DHCALs and others
ILCD R&D,
calibration
Combined CALICE TILE
Combined Calorimeters
, tracking, MDI, etc
PFA and shower library Related Data Taking
Phase 0:
Prep.
Phase I: Detector R&D, PFA
development, Tech. Choice
Phase II
From Jae Yu
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
“Window for Detector R&D
2004
2005
2006
2007
2008
GDE (Design)
2009
2010
(Construction)
Technology
Choice
Acc.
CDR
TDR
Start Global Lab.
Done!
Det.
Detector Outline
Documents
CDRs
LOIs
Detector R&D Panel
Detector
R&D Phase
Collaboration
Forming
Construction
Tevatron
SLAC B
HERA
LHC
T2K
Comment on R&D efforts
- It is clear that there are a number of parallel/overlapping
R&D efforts.
- This was inevitable, and desirable, in the early LC R&D
period.
- R&D funding is generally limited – we must make optimal use
of those resources we have.
- A World Wide Study R&D panel has been formed.
- Each detector concept will survey R&D activity, needs
-> Hopefully this will provide a basis for more efficient use
of limited R&D resources
Calorimeter
Electromagnetic
Technology
Groups
Silicon-Tungsten
BNL, Oregon, SLAC
Silicon-Tungsten
UK, Czech, France, Korea, Russia
Silicon-Tungsten
Korea
Scintillator/Silicon-Lead
Italy
Scintillator/Silicon-Tungsten
Kansas, Kansas State
Scintillator-Lead
Japan, Russia
Scintillator-Tungsten
Japan, Korea, Russia
Scintillator-Tungsten
Colorado
Calorimeter
From
K.Kawagoe @
ACFA 07
Hadronic (analog)
Hadronic (digital)
Tail catcher
Technology
Groups
Scintillator-Steel
Czech, Germany, Russia, NIU
Scintillator-Lead
Japan
GEM-Steel
FNAL, UTA
RPC-Steel
Russia
RPC-Steel
ANL, Boston, Chicago, FNAL
Scintillator – Steel
Northern Illinois/ NICADD
Scintillator – Lead/Steel
Japan, Korea, Russia
Scintillator-Steel
FNAL, Northern Illinois
RPC-Steel
Italy
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
R&D budgets.
- It is critical to carry out an R&D survey and ensure
that Detector R&D proceeds in a timely manner alongside
Accelerator R&D.
This is particularly critical for U.S.-based calorimeter
development which faces significant financial hurdles,
and a long test beam program!