RAS NPS ConferenceITEP26.11.2007
Physics and Detectors at International Linear Collider (ILC)
Мichael Danilov
Institute for Theoretical and Experimental Physics Moscow
New era starts in 2008 – the LHC era. The HEP community is eager to see exciting discoveries at LHC
However already now a large group works hard to develop the next world project– The International Linear Collider
Accelerator design is done within GDE (this will be discussed by A.Skrinsky)
Physics and detector studies are organized within the World Wide Study on Physics and Detectors for ILCwhich combines 3 regional activities in America, Asia, and Europe.
WWS is to a large extent a self-organized activityCoordination is performed by WWS OC (representatives from each region)WWS OC organizes working groups and promotes joint R&D effortsResults are annually discussed at LCWS organized by WWS OC and regional WSs
I’ll give a short review of the work done by several hundred physicistsMany figures (and even slides) are borrowed from the LCWS talks =>many thanks to many people in particular to Y.Okada
Why do we need both LHC & ILC?
• Two machines have different characters.• Advantages of lepton colliders: e+ and e- are elementary particles (well-defined kinematics). Less background than in LHC experiments. Whole energy is available for new phenomena (only ~1/6Etot in LHC, but still more than in ILC) Beam polarization, energy scan.
- e- , e- e- options, Z pole option.
LHC ILC
Hadron and electron colliders provided complementary information in the past
Hadron accelerators
J particle
Beauty
W,Z
e+e- colliders
Ψ particle
Tau lepton
Gluon
We hope this will continue in the future
Signal/ background ratio is much better at ILC
Coupling measurements at ILC
mH=120 GeV, Ecm=300-500 GeV.L=500fb-1
Higgs self-coupling
(Ecm>700 GeV)
LHC: (10)% for ratios of coupling constantsILC: a few % determination
scenario
SUSY particle masses, quantum numbers, couplings, mixing angles can be determined with high accuracy at ILC
Precise determination of SUSY parameters at ILC and LHC allows to achieve accuracy in SUSY Dark Matter density comparable to the accuracy of Planckmeasurements
SUSY Dark matter at ILC
SUSY mass and coupling measurements => Identification of dark matter
Detector Concepts
Four detector concepts are being investigated GLD (Global Large Detector) LDC (Large Detector Concept) SiD (Silicon Detector) 4th concept
Summer 2006: Detector Outline Documents (DOD) evolving documents, detailed description
Summer 2007: Detector Concept Reports (DCR) comprehensive detector descriptions, go along with machine RDR
2010: EDR for only 2 detectors. WWSOC proposed the roadmap: first step – democratic merging. GLD and LDC already merged into ILD If it does not work – a special committee (IDAG)
Requirements for Vertex and Track reconstruction Vertex detector – best flavour tagging
goal impact parameter resolution σrφ ≈ σz ≈ 5 10/(p sinΘ3/2) µm 3 times better than SLD small (R~1.5cm), low mass (~0.1X0) pixel detectors, various technologies under study with pixels ~20×20 µm2 (~109 pixels)
Tracking: superb momentum resolution to select clean Higgs samples ideally limited only by ГZ
→ Δ(1/pT) = 5∙10-5 /GeV (whole tracking system)3 times better than CMS
Options considered:
Large silicon trackers Time Projection Chamber with ≈ 100 µm point resolution (complemented by Si–strip devices)
Established technique but with novel Micropattern Readout
TPC Tracker for LC Detector (Worldwide collaboration)
GEM: Two copper foils separated by kapton, multiplication takes place in holes, uses 2 or 3 stages
140mS1
Micromegas: micromesh sustained by 50μm pillars, multiplication between anode and mesh, one stage
S1/S2 ~ Eamplif / EdriftS2
Micromegas can be produced directly on chip
GEM can be also used
TimePix chip gives first 3d results
256x256 pixel chip with Preamp,Discriminator, DAC, 14-bit counter,…
Individual e- are seen!
LC Physics goals require EJ/√EJ~30%
This can be achieved with Particle Flow Method (PFM): Use calorimeter only for measurement of K,n, and Substitute charged track showers with measurements in tracker
LC detector architecture is based on PFM, which is tested mainly with MC
Experimental tests of PFM are extremely importantWe are building now a prototype of scintillator tile calorimeter to test PFM
Very high granularity is required for Particle Flow MethodIt can be achieved with novel photo-detectors - Silicon Photo Multipliers (SiPM)
(2 layers combined)
Tile size in cm2
(2 layers combined)
Tile size in cm2
Distance =10cm Distance =15cm
The HCAL prototype comprises 38 planes of scintillating detectors with 216 tiles in first 30 planes and 145 tiles in 8 last ones.
SiPM 3х3 cm2 tile with SiPM
Light from a tile is read out via WLS fiber and SiPM
LAL 18 ch. SiPM FE chip
SiPM (MEPhI-Pulsar) main characteristics
R 50
h
pixel
Ubias
Al
Depletion Region2 m Substrate
24m
32m
1156 pixels of 32x32m2 (actvive area 24x24)
Working point: VBias = Vbreakdown + V ~ 50-60 V V ~ 3V above breakdown voltage
Each pixel behaves as a Geiger counter withQpixel = V Cpixel with Cpixel~50fF
Qpixel~150fC=106e
- Noise at 0.5 p.e. ~ 2MHz
- Optical inter-pixel cross -talk:-due to photons from Geiger discharge initiated by one electron and collected on adjacent pixels-Xtalk grows with ΔV. Typical value ~20%.
-PDE ~15% for Y11 spectrum Insensitive to magnetic field (tested up to 4Tesla)
Very short Geiger discharge development < 500 ps
Pixel recovery time = (Cpixel Rpixel) ~ 20 ns (for small R)
Dynamic range ~ number of pixels (1156) saturation
ResistorRn=400 k -20M
Radiation damage measurements
ITEP SynchrotronProtons E=200MeV(preliminary)
Dark current increases linearly with flux Φ as in other Si devices:
Δ I=α Φ Veff Gain, where α=6x10-17A /cm
Veff ~ 0.004mm3 determined from observed ΔI looks a bit too high (since it includes SiPM efficiency)but not completely unreasonable
Since initial SiPM resolution of ~0.15 p.e. is muchbetter than in other Si detectors it suffers sooner:After Φ~1010 individual p.e. signals are smeared out
However MIP signal are seen even after Φ~1011/cm2
At ILC neutron flux is much smaller than 1010/cm2
except a small area (R<30cm) around beam pipe
→ Radiation hardness of SiPM is sufficient for HCAL
CALICE – Si/W Electromagnetic Calorimeter Wafers:
Russia/MSU and Prague
PCB: LAL design, production – Korea/KNU
New design for ECal active gap. Reduction from 3.4mm to 1.75mm, Rm = 1.4cm
High resolution plane at about 3X0 Real 640 m PCB exists
Tungsten: ITEP
ECALTCMT HCAL
SiW ECAL1cm2 pads, 30 layers
Sintillator HCAL, SiPM readout 38 layers
Common DAQ18’000 ch
ECAL
HCAL
Tail catcher 16 scintillator strip layers
with SiPM readout
HCAL, ECAL, and TC have been tested in 2007 at CERN
Set-up at SPS H6b
Hadron event
>4 MIP>1.8MIP & <4MIP>0.5MIP & <1.8MP
Event with 2 hadrons (distance ~6 cm)
Event with 2 hadrons after reconstruction. Two showers separated in depth are visible
Scintillator strips with WLSF and SiPM readout can be used for ILC muon system
Cosmics
N pixels =20
Tests of 2 m long strip at ITEP
Position along strip can be determined from time measurements: Achieved time resolution ΔT~2ns leads to ΔX~25cmMore experience will be gained from TCMT tests
Scintillator tile calorimeter with WLSF and SiPM readout is a viable option for ILC HCAL but industrialization is needed for several hundred times larger systemNew types of SiPMs are being developed by many firms. Final choice of the photodetector depends on overall optimizationComparison with Digital Calorimeter will be made using beam test data
Thin scint. strips with WLSF+SiPM readoutprovide sufficient light and uniformity (~6%)for last layers of EM calorimeter(approach is extensively tested by Japanese groups)
Uniformity measurements for 3x10x45 mm3 strip with WLSF and SiPM readout
ITEP
The same technique can be used for 3 detector systems
Conclusions
Physics at ILC will be very rich and exciting
Detectors are challenging but feasible
ILC gets a lot of momentum.Accelerator EDR and two Detector EDRwill be ready in 2010
It is the right time to join the effort!
Backup slides
The International Linear Collider
2006: Baseline Configuration Document February 2007:
Reference Design Report presented at Beijing ACFA ILC Meeting Layout of the machine:
2 × 250 GeV upgradable to 2 × 500 GeV 1 interaction region 2 detectors (push-pull) 14 mrad crossing angle
Cost estimate: 4.87 G$ shared components+ 1.78 G$ site-dependent= 6.65 G$ (= 5.52 G€)
+ 13000 person years
ICFA FALC
FALC Resource Board
ILCSC
GDEDirectorate
GDEExecutive Committee
GlobalR&D Program
RDR Design Matrix
GDER & D Board
GDEChange Control Board
GDEDesign Cost Board
GDE RDR / R&D Organization
ILCDesignEffort
ILCR&D
Program
WWS OC
Internationl Linear Collider
Timeline 2005 2006 2007 2008 2009 2010
Global Design Effort Project
Baseline configuration
Reference Design
ILC R&D Program
Technical Design
Expression of Interest to Host
International Mgmt
main linacbunchcompressor
dampingring
source
pre-accelerator
collimation
final focus
IP
extraction& dump
KeV
few GeV
few GeVfew GeV
250-500 GeV
Designing a Linear Collider
Superconducting RF Main Linac
Восстановление технологии производства чистого Nb в РоссииПолученный в лаборатории ниобий существенно превосходит западные образцы
Примеси [g/g] DESY ИТЭФ-ГИРЕДМЕТ Ta 500 2.2 W 70 6 Mo 50 <1 Ti 50 <0.03 N 10 3 C 10 3
RRR 300 ~1000
Градиент ~35 МВ/м
Strip efficiency and noise vs threshold
1000x40x10 mm3
coated with TiO2 white paint
Ø1.2 mm Kuraray Y11 WLS fiber glued into a groove
Strip to strip uniformity measured for 149 strips
RMSmean
=15%
ILC 2006 workshop Valencia 6-10 November E.Tarkovsky ITEP
Test of ~150 strips with MRS APD
Threshold, pixels
Effi
cien
cy
SUSY relation
M.M.Nojiri, K.Fujii, and T.Tsukamoto
Right-handed selectron production
SUSY predicts characteristic relationsamong superpartner’s interactions.
Radion-Higgs mixing in extra-dim model
Little Higgs model with T parity
C.-R.Chen, K.Tobe, C.-P. Yuan
The triple Higgs coupling in 2HDMin the electroweak baryogenesis scenario
HEPAP report
S.Kanemura, Y. Okada, E.Senaha
Deviation to 5-10 % level can be distinguished at ILC
Higgs boson search at LHC
MH(GeV)
5
SM Higgs boson branching ratio Higgs boson discovery at LHC
Z’ and e+e-->ff processesEven if ILC at 500 GeV cannot produce a new Z’ particle kinematically,we can determine left-handed and right-handedcouplings from ee-> ff processes.This will give important information to identify the correct theory.
S.Godfrey, P.Kalyniak, A.Tomkins
m z’ =2TeV,Ecm=500 GeV, L=1ab-1
with and w/o beam polarization
e
e
f
f
Z’
LHC=> massILC => coupling
Z’ coupling determination at ILC
New physics effects in Higgs boson couplings • In many new physics models, the Higgs sector is
extended and /or involves new interactions. The Higgs boson coupling can have sizable deviation from the SM prediction.
B(h->bb)/B(h->)
LC
J.Guasch, W.Hollik,S.Penaranda
B(h->WW)/B(h->)
LHC
LC
The heavy Higgs boson mass in the MSSM SUSY correction to Yukawa couplings
ACFA report
LHC может открыть
SUSY с массой до ~1ТэВ
Однако определить все
свойства этих частиц
будет сложно
Для этого планируется
создать е+е- коллайдер-
ILC c энергией 0.5-1ТэВ
Частица Тёмной Материи
Dark matter and collider physics• Energy composition of the
Universe Dark energy 73% Dark matter 23% Baryon 4%• Dark matter candidate WIMP ( weakly interacting
massive particle) a stable, neutral particle • WIMP candidates Neutralino (SUSY) KK-photon (UED) Heavy photon (Little Higgs with
T parity)…
MINICAL tests with electron beam
Very good agreement between SiPM, MAPMT, APD(not shown) and MC in the whole range 1 - 6 GeVSIPM non-linearity can be corrected even for dense e/m showers for each tile and does not deteriorate resolution Possibility to observe peaks for different number of p.e. crucial for calibrationLow sensitivity to constant term due to limited energy range
Measurement of electron energy with HADRON CALORIMETER resolution modest
Detector Concepts
GLD - TPC tracking large radius - particle flow calorimeter - 3 Tesla solenoid - scint. fibre µ detector
LDC - TPC tracking smaller radius - particle flow calorimeter - 4 Tesla solenoid - µ detection: RPC or others
Detector Concepts SiD - silicon tracking - smaller radius - high field solenoid (5 Tesla) - scint. fibre / RPC µ detector
Silicon tracker
6.45 m
6.45 m
Magnet - high field - but smaller volume
• CMS
The Particle Flow Concept
What is the best way to measure the energy of a jet?
Classical: purely calorimetric typically 30% e.m. and 70% had. energy for E/E(em) = 10%/E and E/E(had) = 50%/E E/E(jet) ~ 45%/E
PFlow: combine tracking and calorimetry typically 60% charged, 30% em(neut), 10% had(neut) need to separate charged from neutral in calorimeter! momentum resolution negligible at ILC energies E/E(jet) ~ 20%/E in principle (for ideal separation) E/E(jet) ~ 30%/E as a realistic goal
PFlow has further advantages: tau reconstruction leptons in jets multi-jet separation (jet algorithms…) talk by S. Yamashita
Vertex Detector
space point resolution < 5 µm; pixel size ~20×20 µm2 (~1/30? wrt LHC) smallest possible inner radius ri ≈ 15 mm ( ~1/5 wrt LHC) transparency: ≈ 0.1% X0 per layer = 100 µm of silicon (~1/30? wrt LHC) stand alone tracking capability full coverage |cos Θ| < 0.98 modest power consumption < 100 W five layers of pixel detectors plus forward disks (~109 channels)
Vertex Detector
Critical issue is readout speed: Inner layer can afford O(1) hit per mm2 (pattern recognition)
once per bunch = 300 ns per frame too fast once per train ≈ 100 hits/mm2 too slow 20 times per train ≈ 5 hits/mm2 might work 50 µs per frame of 109 pixels!
→ readout during bunch train (20 times) or store data on chip and readout in between trains e.g. ISIS: In-situ Storage Image Sensor
Many different (sensor)-technologies under study CPCCD, MAPS, DEPFET, CAPS/FAPS, SOI/3-D, SCCD, FPCCD, Chronopixel, ISIS, … → Linear Collider Flavour Identification (LCFI) R&D collaboration Below a few examples Note: many R&D issues independent of Si-technology (mechanics, cooling, …)
Vertex Detector
0.1*(Npix/MIP)
(Npix/MIP)*HV
Npix/MIP GAIN
0.1*GAINGAIN*HV
RESPONSE EFFICIENCY
NOISE CROSSTALK
0.1*EFFICIENCYEFFICIENCY*HV
0.1*RESPONSERESPONSE*HV
0.1*CROSSTALKCROSSTALK*HV
0.1*NOISENOISE*HV
HV-HVoper, V HV-HVoper, V
HV-HVoper, V HV-HVoper, V HV-HVoper, V
HV-HVoper, V HV-HVoper, V HV-HVoper, V
Response Pedestal RMS Gain
N pixels per MIP Crosstalk Number of p.e. per MIP
Noise, kHz Noise at ½ MIP, Hz
The value of HVoper
corresponds to 15 pixels per MIP. One can see that we have about 70% of maximal efficiency at
chosen HVoper.
Recently low noise blue sensitive MPPC with high PDE were developed by HPK
Comparison of different Multipixel Geiger Photo Diods (MGPD) (MPPC(1600 pix), SiPM (1156 pix), MRS APD(656pix))
MGPD were illuminated withY11 (green) and scintillator (blue) lightEfficiency was normalizedto MPPC one
MRS APD with 25% largerefficiency already exist.
.
Noi
se
freq
uenc
y
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