1. Detectors for Linear Colliders - ILC and CLIC -
Hitoshi Yamamoto
Tohoku University
IEEE, Special LC event
Anaheim, CA, Oct 28, 2012

2. LC features : cleanliness
Collision of two elementary particles
electron + positron at LC
proton + proton at LHC
Proton = 3 quarks + gluons
→ Signal is clearly seen without much noises
→ Trigger-less data taking
→ Theoretically clean (less theoretical uncertainties)
LHC LC
All from Higgs

3. LC features : control Initial state of electron-positron interaction :
Energy-momentum 4-vector is specified
Electron polarization is specified
Positron polarization is optional
Energy-momentum 4-vector
→ e.g. recoil mass analysis
Higgs to ALL (including invisible final state) is seen LC
LHC

4. Electron polarization
Specify the intermediate state
Right-handed e- turns off A0
Information on the character of the final state
Right-handed e- turns off W
Background rejection e+
g,Z
(B,A0) e- e+ W+ e- W-
e.g. acoplanar muon pair produciton

5. Measurement errors of Higgs couplings
LHC 14 TeV 3000 fb-1 and LC 500 GeV 500 fb-1
D. Zerwas
Apart from top and g, LC errors are 1/4~1/10 of LHC
(statistical equivalent: 1~2 orders of magnitude more)

6. Multi-TeV LC (CLIC) Higgs statistics becomes larger at higher ECM
Higgsstrahlung
W fusion
(LC input to European Strategy)
SUSY ‘Model II’
Hnn (ZH) mode dominates at high (low) ECM
Switchover point ~ 500 GeV
~15 times more Higgs at 3 TeV than at 250 GeV
good for e.g. Higgs self coupling
And new particles!

7. LC Detector Performances
Vertexing
~1/5 rbeampipe,1/50~1/1000 pixel size, ~1/10 resolution (wrt LHC)
Tracking
~1/6 material, ~1/10 resolution (wrt LHC)
Jet energy (quark reconstruction)
1000x granularity, ~1/2 resolution (wrt LHC)
Above performances achieved in realistic simulations

8. Impact parameter resolution
Alice
Belle
ATLAS
LHCb
ILC

9. Jet(quark) reconstruction
Current
Goal
is required for Z/Wjj to be separated
A promising technique : PFA (particle flow algorithm)

10. PFA Charged particles Neutral particles
Use trackers
Neutral particles
Use calorimeters
Remove double-couting of charged showers
Requires high granularity
ILD
#ch
ECAL
HCAL
ILC (ILD)
100M
10M
LHC
76K(CMS)
10K(ATLAS)
X103 for ILC
Need new technologies !

11. T. Yoshioka e+ e-
Next: 電子、陽電子衝突

12. T. Yoshioka
Find the photons and remove them

13. T. Yoshioka
Identify the showers associated with charged tracks and remove them.

14. T. Yoshioka
Clean up the noise
The rest: neutral hadrons

15. Jet energy resolution Jet Energy Resolution s/Ejet (%)
ALEPH measured
CDF measured
ATLAS simulation
H1 measured
DREAM
measured
PFA
simulation
ILC goal
Jet Energy (GeV)

16. General Considerations (1)
Calorimeters inside solenoid
For good jet reconstruction
Low mass for tracking&vertexing
Thinned silicon sensors
e.g. ~50 mm for pixel vertex detectors
Light support structures
e.g. advanced endplate for TPC
High granularity for calorimeters&vertexing
Fine-granularity calorimeter readout
Silicon pad, SiPM, RPC, GEM etc.
State-of-the-art pixel technologies for vertexing
CMOS, FPCCD, DEPFET, SOI, 3D…
Front-end electronics embedded in/near the active area (cabling!)

17. General Considerations (2)
As hermetic as possible
Vertex detector as close as possible to beam
Limit: e+e- pair background
Low heat generation (cooling eats up material budget)
Low-power front-end electronics
Power pulsing
Turn off power during bunch train gap
CLIC 3 TeV
Density of pairs near IP
High B field helps
Worse for high ECM
Beam pipe
#bunch/train
Train length
Train gap
Duty factor
ILC
1312
727 ms
200 ms
0.36%
CLIC
312
156 ns
20 ms
0.001%

18. ILC Detectors

19. ILC Detector Schedule IDAG (International Detector Advisory Group):
Validated two detectors: ILD and SiD in 2009 summer
ILD and SiD:
working toward DBD (Detailed Baseline Design) (end 2012)
New ILC organization will take over the current one Feb 2013.

20. ILD B: 3.5 T Vertex pixel detectors 6 (3 pairs) or 5 layers (no disks)
Technology open
Si-strip trackers
2 barrel + 7 forward disks (2 of the disks are pixel)
Outer and endcap of TPC
TPC
GEM or MicroMEGAS for amplification
Pad (or si-pixel) readout
ECAL
Si-W or Scint-W (or hybrid)
HCAL
Scint-tile or Digital-HCAL
All above inside solenoid

21. SiD B: 5T Vertex pixel detectors 5 barrel lyrs + (4 disks+3 fwd)/side
Technology open (3D)
Si-strip-trackers
5 barrel lyrs + 4 forward disks/side
EMCAL
Si-W 30 lyrs, pixel ~(4mm)2
HCAL
Digital HCAL with RPC or GEM with (1cm)2 cell
40 lyrs
All above inside solenoid

22. Design Strategies SiD High B field (5 Tesla) Small ECAL ID
Small calorimeter volume
Finer ECAL granularity
Silicon main tracker
ILD
Medium B field (3.5 Tesla)
Large ECAL ID
Particle separation for PFA
Redundancy in tracking
TPC for main tracker

23. LC-TPC collaboration Goal: develop ILD TPC ‘Large’ prototype made
D = 0.7m, L=0.6m
Beam test under 1Tesla (DESY)
Both GEM and MicroMEGAS
So far so good.
Issue:
ion feedback, thin endplate
Prototype endplate

24. Calorimeter Beam Tests
Beam tests at FNAL, CERN, DESY
SDHCAL
SiW-ECAL
300 GeV π in W-DHCAL
W-DHCAL
Coparison with MC tests :
• hadron shower generation software
• detector simulation

25. CLIC Detectors

26. ILC and CLIC Apart from the difference in bunch time structure,
CLIC 500 GeV ~ ILC 500 GeV
In detector design
In physics performance
CLIC 3 TeV :
Higher shower energies
Higher pair background
Large difference in 0.5→3 TeV
Higher gg→hadron background
High occupancies
Incoherent pairs

27. S vs T channel T-channel S-channel e.g. e.g. Cross section ∝ 1/S
decreases with S
Particles → barrel region
Cross section ∝ log S
increases with S
Particles → forward region
At high energy (3 TeV), T-channel processes tend to
dominate.
Lots of backgrounds in forward region
- esp. gg → hadrons.

28. Pileiup Degradation (3 TeV)
20 TeV of energy deposit / bunch train
gg→hadrons and pair background
Pair background is mostly in endcaps
Affects physics performances e.g. jet energy resolution
1BX = 0.5 ns

29. Time Stamping (3 TeV) Within reconstruction window After timing cuts
Still ~ 1TeV of pileups
After timing cuts

30. From ILC to CLIC Detectors
Also:
• Better time resolutions
• Beam crossing angle
14 → 20 mrad
Pair background
Recess VTX
Higher energy jet
Deeper HCAL
Use W for barrel 30

31. CLIC-ILD
CLIC-SiD

32. Jet reconstruction - PFA (Pandra)
● PANDRA PFA codes applied to CLIC-ILD
and CLIC-SiD
● Meets the jet energy resolution goal
(3~4%) up to 1500 GeV jet.
M. Thomson

33. Summary
LC physics goals are realized by detectors that push the envelope of current state-of-the-art
LC detectors are characterized by unprecedented high resolutions
They are made possible by lightweight and high granularity design
CLIC originally adopted the ILC detector designs, but now CLIC detector studies are feeding back into ILC detector efforts

34. Backup

35. LC Detector R&D Groups Driven by ‘horizontal’ collaborations
M. Demarteau