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