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

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

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

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

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)

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!

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

Impact parameter resolution Alice Belle ATLAS LHCb ILC

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

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 !

T. Yoshioka e+ e- Next: 電子、陽電子衝突

T. Yoshioka Find the photons and remove them

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

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

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)

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!)

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%

ILC Detectors

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.

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

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

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

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

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

CLIC Detectors

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

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.

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

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

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

CLIC-ILD CLIC-SiD

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

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

Backup

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