Physics and Detectors of the International Linear Collider

Physics and Detectors of the International Linear Collider Jim Brau Univ. of Oregon Lecture presented at the Second International Accelerator School for Linear Colliders, Erice, Italy October 9, 2007 1

Physics and Detectors of the International Linear Collider m LHC will open exploration of Terascale physics o o o m ILC is needed to explore and elucidate nature of Terascale Ä Ä m Deep significance to fundamental physics What is nature of Electro. Weak Symmetry Breaking? Are there new symmetries of space and time? Are there hidden extra dimensions? Dark matter particles might explain astrophysical observations Deeper look into Terascale questions Precision exploration of new physics Sophisticated, precise detectors are required to exploit the scientific opportunity of the ILC ENORMOUS EFFORTS ON MANY ASPECTS THIS TALK IS NECESSARILY SELECTIVE DUE TO BREADTH OF SUBJECT 2

ILC Physics Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 3

Electroweak Symmetry Breaking m A central focus of particle physics research today is the origin of Electroweak Symmetry Breaking Ä The weak nuclear force and the electromagnetic force have been unified into a single description SU(2) x U(1)Y Ä Why is this symmetry hidden? Ä The answer to this appears to promise deep understanding of fundamental physics v v v the origin of mass supersymmetry and possibly the elements of dark matter additional unification (strong force, gravity) and possibly hidden space-time dimensions 4

Electromagnetism and Radioactivity m Maxwell unified Electricity and Magnetism with his famous equations (1873) m Matter spontaneously emits penetrating radiation Ä Becquerel uranium emissions in 1896 Ä The Curies find radium emissions by 1898 This new interaction (the weak force) is related to E&M 5

Advancing understanding of Beta Decay m Pauli realizes there must be a neutral invisible particle accompanying the beta particle: Ä m the neutrino beta energy Fermi develops a theory of beta decay (1934) n p e- e m neutrino 1956 - Neutrino discovered Reines and Cowan - Savannah River Reactor, SC 6

EM and Weak Theory in 1960 Weak Interaction Theory m Fermi’s 1934 pointlike, four-fermion interaction theory V-A n m p e Theory fails at higher energy, since rate increases with energy, and therefore will violate the “unitarity limit” n p Ä Speculation on heavy mediating bosons but no theoretical guidance on what to expect W e 7

EM and Weak Theory in 1960 Quantum Electrodynamics (QED) m Dirac introduced theory of electron - 1928 m Through the pioneering theoretical work of Feynman, Schwinger, Tomonga, and others, a theory of electrons and photons was worked out with precise predictive power example: magnetic dipole of the electron [(g-2)/2] m = g (eh/2 mc) S m m current values of electron (g-2)/2 theory: 0. 5 (a/p) - 0. 32848 (a/p)2 + 1. 19 (a/p)3 +. . = (115965230 10) x 10 -11 experiment = (115965218. 6 0. 4) x 10 -11 8

The New Symmetry Emerges 9

Enter Electroweak Unification m Weinberg realized that the vector field responsible for the EM force Ä the photon and the vector fields responsible for the Weak force Ä m yet undiscovered W+ and W- could be unified if another vector field, mediated by a heavy neutral boson (Z 0), were to exist This same notion occurred to Salam g’/g tan W sin 2 W = g’ 2/(g’ 2+g 2) e J (em) A e = g sin W = g’ cos W 10

Electroweak Unification m There remained a phenomenological problem: Ä m These do not appear so clearly in Nature Ä m where were the effects of the Z 0 they are small effects in the atomic electron energy level One has to look for them in high energy experiments Discovered 1973 -CERN Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 11

Confirmation of Neutral Currents m Weinberg-Salam Model predicts there should be some parity violation in polarized electron scattering Ä The dominant exchange is the photon (L/R symmetric) Ä A small addition of the weak neutral current exchange leads to an expected asymmetry of ~ 10 -4 between the scattering of left and righthanded electrons Z 0 exchange violates parity polarized e d Ä Ä Ä Jim Brau polarized + e d Prescott et al. (SLAC) 1978 confirms theory first accurate measurement of weak mixing angle Z 0 g. R g. L An asymmetry of 10 -4 sin 2 W = 0. 22 0. 02 Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 12

W and Z Masses m Knowing sin 2 W allows one to predict the W and Z boson masses in the Weinberg-Salam Model ~ 80 Ge. V/c 2 ~ 90 Ge. V/c 2 TREE LEVEL EXPRESSIONS m Jim Brau Motivated by these predictions, experiments at CERN were mounted to find the W and Z Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 13

Discovery of the W and Z Antiprotons stored at CERN in 1981 W- e n e PT u miss PT p=uud e W- d p=uud ne UA 1 and UA 2 discovered the W and the Z bosons Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 14

Discovery of the W and Z m m That was over 20 years ago Since then: Ä Ä precision studies at Z 0 Factories v LEP and SLC precision W measurements at colliders v LEP 2 and Te. Vatron MZ = 91187. 5 2. 1 Me. V m These precise measurements (along with other precision measurements) test the Standard Model with keen sensitivity Ä Jim Brau MW = 80398 25 Me. V/c 2 eg. are all observables consistent with the same value of sin 2 W Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 15

Electroweak Symmetry Breaking Confirmation of the completeness of the Standard Model e+e- W+W- (LEP 2) Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 16

The Higgs Boson m Why is the underlying SU(2)x. U(1) symmetry broken = m Jim Brau Theoretical conjecture is the Higgs Mechanism: a non-zero vacuum expectation value of a scalar field, gives mass to W and Z and leaves photon massless Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 17

The Higgs Boson m This scalar field, like any field, has quanta, the Higgs Boson or Bosons Ä Minimal model - one complex doublet 4 fields — 3 “eaten” by W+, W-, Z to give mass — 1 left as physical Higgs m m This spontaneously broken local gauge theory is renormalizable - t’Hooft (1971) The Higgs boson properties Ä Mass < ~ 800 Ge. V/c 2 (unitarity arguments) v Ä Strength of Higgs coupling increases with mass v v Jim Brau but hierarchy problem fermions: gffh = mf / v v = 246 Ge. V gauge boson: gwwh = 2 m. Z 2/v Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 18

Anticipated Particles Positron Neutrino Pi meson Quark Charmed quark Bottom quark W boson Z boson Top quark Dirac theory of the electron Higgs boson Electroweak theory and experiments Jim Brau missing energy in beta decay Yukawa’s theory of strong interaction patterns of observed particles absence of flavor changing neutral currents Kobayashi-Maskawa theory of CP violation Weinberg-Salam electroweak theory “ “ Mass predicted by precision Z 0 measurements Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 19

The Search for the Higgs Boson m LEP II (1996 -2000) MH > 114 Ge. V/c 2 (95% conf. ) Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 20

Standard Model Fit JULY 2007 m MH = 76 +33 Ge. V/c 2 Jim Brau -24 Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 21

Light Standard Model-like Higgs JULY 2007 (SM) Mhiggs < 144 Ge. V at 95% CL. LEP 2 direct limit Mhiggs > 114. 4 Ge. V. W mass ( 25 Me. V) and top mass ( 2 Ge. V) consistent with precision measures and indicate low SM Higgs mass LEP Higgs search – Maximum Likelihood for Higgs signal at m. H = 115. 6 Ge. V with overall significance (4 experiments) ~ 2 Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 22

The Search for the Higgs Boson m Tevatron at Fermilab Ä Ä m LHC at CERN Ä Ä Jim Brau Proton/anti-proton collisions at Ecm= 2000 Ge. V through 2009 (perhaps 2010) Proton/proton collisions at Ecm=14, 000 Ge. V First collisions in 2008 Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 23

Models of Electroweak Symmetry Breaking Standard Model Higgs excellent agreement with EW precision measurements implies MH < 175 Ge. V (but theoretically ugly - h’archy prob. - Mh unstable) MSSM Higgs expect Mh< ~135 Ge. V light Higgs boson (h) may be very “SM Higgs-like” (de-coupling limit) Non-exotic extended Higgs sector eg. 2 HDM Strong Coupling Models New strong interaction The ILC will provide critical data to assess these possibilities Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 24

Complementarity of Electron Colliders Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 25

The Large Hadron Collider and the ILC m m m LHC at CERN, colliding protons first collisions – next year History demonstrates the complementarity of hadron and electron experiments discovery facility of detailed study charm tau bottom Z 0 BNL + SPEAR Fermilab SPPS/CERN SPEAR at SLAC Cornell/DESY B Factories LEP and SLC Electron experiments have frequently provided most precision Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 26

Complementarity with LHC SUSY mass and coupling measurements => Identification of dark matter Z’ discovered at LHC Couplings determined at ILC m z’ =2 Te. V, Ecm=500 Ge. V, L=1 ab-1 with and w/o beam polarization S. Godfrey, P. Kalyniak, A. Tomkins Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 27

ILC Physics Program o Higgs Mechanism o Supersymmetry o Strong Electroweak Symmetry Breaking o Precision Measurements at lower energies Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 28

Higgs Physics Program of the ILC Electroweak precision measurements suggest there should be a relatively light Higgs boson: When it’s discovered, its nature must be studied. The ILC is essential to this program. Mass Measurement (~50 Me. V at 120 Ge. V) Total width Particle couplings vector bosons fermions (including top) Spin-parity-charge conjugation Self-coupling�� H ? H The ILC makes precise measurements Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 29

Higgs Production Cross-section ILC program ~ 500 events / fb Higgs-strahlung WW fusion pt = 87 nb / (Ecm)2 ~ 350 fb @ 500 Ge. V Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 30

Higgs Studies - the Power of Simple Interactions ILC observes Higgs recoiling from a Z, with known CM energy • powerful channel for unbiassed tagging of Higgs events • measurement of even invisible decays ( - some beamstrahlung) • Tag • Select Mrecoil = MHiggs Z l+ l Invisible decays are included 500 fb-1 @ 500 Ge. V, TESLA TDR, Fig 2. 1. 4 Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 31

Higgs Couplings the Branching Ratios gffh = mf / v v = 246 Ge. V Measurement of BR’s is powerful indicator of new physics e. g. in MSSM, these differ from the SM in a characteristic way. Higgs BR must agree with MSSM parameters from many other measurements. Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 32

Is This the Standard Model Higgs? b vs. W TESLA TDR, Fig 2. 2. 6 Arrows at: MA = 200 -400 MA = 400 -600 MA = 600 -800 MA = 800 -1000 HFITTER output conclusion: for MA < 600, likely to distinguish Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 33

Is This the Standard Model Higgs? Precision tells us! Yamashita Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 34

Higgs Self Coupling Φ(H)=λv 2 H 2 + λv. H 3 + 1/4λH 4 SM: g. HHH = 6λv, fixed by MH Δλ/λ ~ 10 -20 % for 1 ab-1 Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 35

Higgs Spin Parity and Charge Conjugation (JPC) H or H rules out J=1 and indicates C=+1 Production angle ( ) and Z decay angle in Higgs-strahlung reveals JP (e+ e Z H ff. H) LC Physics Resource Book, Fig 3. 23(a) Jim Brau TESLA TDR, Fig 2. 2. 8 Linear Collider Physics and Detectors of the International Erice, October 9 , 2007 36

New Physics Beyond the Higgs m Motivated by Hierarchy Problem Ä Gigantic Mismatched between electroweak scale (100 Ge. V) and the Planck Scale (1019 Ge. V) § Supersymmetry § new space-time symmetry with new particles § New Strong Interactions § Hidden Dimensions Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 37

Supersymmetry m Supersymmetry Ä particles matched by super-partners v v Ä Ä inspired by string theory cancellation of divergences v Ä Ä Solves “hierarchy problem” dark matter? many new particles v Jim Brau super-partners of fermions are bosons super-partners of bosons are fermions ILC could detail properties Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 38

Why Supersymmetry #1 It solves the hierarchy problem H 0 W± H 0 = - H 0 The Higgs mass naturally diverges in Standard Model. SUSY cancels diverges exactly for unbroken SUSY. Weak breaking (that is ~1 Te. V) solves this problem. Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 39

Why Supersymmetry #2 Gauge coupling constants unify Minimal supersymmetric SM (Requires light (< Te. V) partners of EW gauge bosons) This is achieved for sin 2 WSUSY= 0. 2335(17) Experiment: sin 2 Wexp = 0. 2314(2) Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 40

Why Supersymmetry #3, #4, #5 #3: Provides cold dark matter candidate If lightest SUSY particle is stable, it is an excellent dark matter candidate. #4: Link to gravity SUSY offers theoretical link to incorporate gravity. Most string models are supersymmetric. #5: Predicts light Higgs boson SUSY predicts a light (< 135 Ge. V) Higgs boson as favored by EW precision data. Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 41

Supersymmetry Mass spectrum is model dependent Squarks are well measured at LHC Sleptons/Neutralinos may benefit from precise spectroscopy at the Linear Collider 42

Sparticle Mass Models Next to lightest Visible Sparticle vs. Lightest Visible Sparticle Ellis, Olive, Santoso, & Spanos Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 43

Lightest visible sparticle (Ge. V) → LSP Usually Lightest invisible sparticle (Ge. V)→ Kalinowski e+e- χ1χ2 Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 44

Is Dark Matter SUSY? Precise measurement of couplings by the ILC critical to this understanding Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 45

Extra Dimensions m Extra Dimensions Ä Ä string theory inspired solves hierarchy problem (Mplanck >> MEW) v Ä if extra dimensions are large extra dimensions observable at ILC Linear collider Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 46

Cosmic connections m m m Jim Brau Early universe GUT motivated inflation Dark matter Accelerating universe Dark energy What happened to the anti-matter? Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 47

Detectors for the International Linear Collider Detector Requirements are defined by ILC machine parameters physics goals ILC creates new challenges and opportunities, different in many respects from the challenges and opportunities of the LHC detectors Physics motivates Triggerless event collection (software event selection) Extremely precise vertexing Synergistic design of detectors components: vertex detector, tracker, calorimeters integrated for optimal jet reconstruction Advanced technologies based on recent detector innovations Detector R&D to optimize ILC opportunity is critically needed Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 49

ILC Experimental Advantages Elementary interactions at known Ecm* eg. e+e- Z H * beamstrahlung manageable Democratic Cross sections eg. (e+e - ZH) ~ 1/2 (e+e - d d) Inclusive Trigger total cross-section Highly Polarized Electron Beam ~ 80% (positron polarization? – R&D) Exquisite vertex detection eg. Rbeampipe ~ 1 cm and hit ~ 3 mm Calorimetry with Particle Flow Precision E/Ejet ~ 3% for Ejet > 100 Ge. V Advantage over hadron collider on precision meas. eg. H c c Detector performance translates directly into effective luminosity Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 50

Power of Constrained Initial State + Simple Reactions • Well defined initial state • Democratic interactions Higgs recoiling from a Z, with known CM energy , provides a powerful channel for unbiassed tagging of Higgs events, allowing measurement of even invisible decays ( - some beamstrahlung) 500 fb-1 @ 500 Ge. V, TESLA TDR, Fig 2. 1. 4 Jim Brau Demands Precise Tracking Physics and Detectors of the International Linear Collider Erice, October 9, 2007 51

Effect of Tracking Resolution Jim Brau Recoil Mass (Ge. V) Physics and Detectors of the International Linear Collider Erice, October 9, 2007 52

The Electroweak Precision Measurements Anticipate a Light Higgs – Then What? m Measurement of BR’s is powerful indicator of new physics e. g. in MSSM, these differ from the SM in a characteristic way. m Higgs BR must agree with MSSM parameters from many other measurements. Vertex Detector Impact Parameter Resolution 10 mm 6 mm 2 mm Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 53

Detector R&D Required • Performance requirements for ILC Detector exceed state-of-the-art – Calorimeters with ~100 million cells being developed for PFA • Jet resolution goal ~ 3 -4% for Ejet > 100 Ge. V – Pixel Vertex Detector with ~109 £ 20 m pixels 5 µm Å 10µm/(p sin 3/2 ) • Impact parameter resolution • Sensitivity to full 1 msec bunchtrain – Tracking resolution • TPC with silicon • Silicon microstrips – High Field Solenoid up to 5 Tesla – High quality forward tracking systems – Triggerless readout • R&D Essential DISCOVERY OPPORTUNITY IS GREAT - limited by detector performance small cross sections/significant backgrounds - advances different from LHC required Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 54

Collider Parameters Machine parameter Value (approx. ) #bunches/train 2820 #trains/sec bunch spacing bunches/sec 5 14100 868 msec train spacing 199 msec Luminosity Incoming beam 308 nsec length of train crossing angle 20 mrad Disrupted beam QFEX 1 QFEX 2 18 14 mrad 2 x 1034 cm-2 s-1 14 mrad push-pull Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 55

Background Sources IP Backgrounds m Beam-beam Interactions Ä Disrupted primary beam v Extraction line losses Beamstrahlung photons Ä e+e- pairs Radiative Bhabhas hadrons/ + Ä m m m m Machine backgrounds Muon production at collimators Collimator edge scattering Beam-gas Synchrotron radiations Neutrons from dumps/extr. line Somewhat manageable m Scale with luminosity m Transport them away from IP m Shield sensitive detectors m Exploit detector timing m Harder to handle m Don’t make them m Keep them from IP if you do m m Jim Brau Reliable simulations. Dominated by beam halo Dependent on assumptions Physics and Detectors of the International Linear Collider Erice, October 9, 2007 56

VXD background hits 8. 5 /mm 2/train GLD study Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 57

Event Rates and Backgrounds m Event rates (Luminosity = 2 x 1034) Ä e+e- → qq, WW, tt, HX v Ä e+e- → e+e- γγ → e+e- X v m ~ 0. 1 event / train ~ 200 /train Background Ä Ä 6 x 1010 γ / BX (from synchrotron radiation, scatters into central detector) 40, 000 -250, 000 e+e- / BX (90 -1000 Te. V) @ 500 Ge. V Muons: < 1 Hz/cm 2 (w/ beamline spoilers) Neutrons: ~3 x 108 /cm 2/ yr @ 500 Ge. V Ref: Maruyama, Snowmass 2005 Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 58

The Concepts LDC Si. D GLD Teams working on LDC and GLD are in the process of merging ILD Jim Brau Physics and Detectors of the International Linear Collider 4 th Erice, October 9, 2007 59

ILC Detector Requirements m Two-jet mass resolution comparable to the natural widths of W and Z for an unambiguous identification of the final states. m Excellent flavor-tagging efficiency and purity (for both b- and c-quarks, and hopefully also for s-quarks). m Momentum resolution capable of reconstructing the recoilmass to di-muons in Higgs-strahlung with resolution better than beam-energy spread. m Hermeticity (both crack-less and coverage to very forward angles) to precisely determine the missing momentum. m Timing resolution capable of separating bunch-crossings to suppress overlapping of events. Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 60

The Concepts Tracking ECal Inner Radius Solenoid EM Cal Hadron Cal Other Si. D silicon 1. 27 m 5 Tesla Si/W Digital (RPC. . ) Had cal inside coil LCD TPC gaseous 1. 58 m 4 Tesla Si/W Digital or Analog Had cal inside coil GLD TPC gaseous 2. 1 m 3 Tesla W/ Scin. Pb/ Scin. Had cal inside coil 4 th TPC gaseous 1. 5 m 3. 5 Tesla crystal Dual readout fiber ILD Jim Brau Physics and Detectors of the International Linear Collider Double Solenoid (open mu) Erice, October 9, 2007 61

Linear Collider Events m Simple events (relative to Hadron collider) make particle level reconstruction feasible m Heavy boson mass resolution requirement sets jet energy resolution goal This event shows single bunch crossing in tracker, 150 bunches in the vertex detector Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 62

Example Concept - Si. D (the Silicon Detector) CALORIMETRY IS THE STARTING POINT IN THE Si. D DESIGN assumptions m Particle Flow Calorimetry will result in the best possible performance m Silicon/tungsten is the best approach for the EM calorimeter m Silicon tracking delivers excellent resolution in smaller volume m Large B field (5 Tesla) desirable to contain electron-positron pairs in beamline m Cost is constrained Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 63

Calorimetry Current paradigm: Particle Flow m Jet resolution goal is 30%/ E m In jet measurements, use the excellent resolution of tracker, which measures bulk of the energy in a jet Neutral Hadro ns EM Headroom for Particles in Jet Fraction of Visible Energy Charg ed Hadro confusion ns Detector Resolution Charged ~65% Tracker < 0. 005% p. T negligible Photons ~25% ECAL ~ 15% / E Neutral Hadrons ~10% ECAL + HCAL ~ 60% / E Jim Brau Physics and Detectors of the International Linear Collider < 20% / E Erice, October 9, 2007 64

EM Calorimetry m m Physics with isolated electron and gamma energy measurements require ~10 -15% / E 1% Particle Flow Calorimetry requires fine grained EM calorimeter to separate neutral EM clusters from charged tracks entering the calorimeter Ä Small Moliere radius v Ä Ä v v Jim Brau Iron 18. 4 mm Lead 16. 5 mm Tungsten 9. 5 mm Uranium 10. 2 mm Tungsten Maximize BR 2 One technology choice – Si/W calorimeter v Ä RM Small sampling gaps – so not to spoil RM Separation of charged tracks from jet core helps v Ä material Good success using Si/W for Luminosity monitors at SLD, DELPHI, OPAL, ALEPH Oregon/SLAC/BNL/Davis/Annecy CALICE Si/W Another choice - Scintillator sampling Physics and Detectors of the International Linear Collider Erice, October 9, 2007 65

Silicon/Tungsten EM Calorimeter Si. D ~ 3. 5 mm SLAC/Oregon/BNL/Davis/Annecy (proposed at Snowmass 1996 - JB, A. Arodzero, D. Strom: Proceedings - 1996 DPF/DPB Summer Study, pg. 437 (1997)) Si/W also being developed by CALICE Collaboration Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 66

Silicon/Tungsten EM Calorimetry for ILC r-> p+po Jim Brau SLAC/Oregon/BNL/Davis/Annecy Dense, fine grained silicon tungsten calorimeter (builds on SLC/LEP experience) m Pads: 12 mm 2 to match Moliere radius (~ Rm/4) m Each six inch wafer read out by one chip m < 1% crosstalk Electronics design m Noise < 2000 electrons m Single MIP tagging (S/N ~ 7) m Dynamically switchable feedback capacitor scheme achieves required dynamic range: 0. 1 -2500 MIPs – 4 deep storage/bunch train Passive cooling – conduction in W to edge Physics and Detectors of the International Linear Collider Erice, October 9, 2007 67

Scintillator/Tungsten ECAL m m Cheaper and larger granularity (3 x 3 - 5 x 5 cm 2) Scintillator strips may be cost-effective way for granularity Ä m (1 cm x Ycm) Read out by fibre + PMT or Si. PM/MPPC Colorado -staggered cells 5 cm x 5 cm Japan/Korea/Russia Jim Brau Si. PMs (invented in Russia) Physics and Detectors of the International Linear Collider Erice, October 9, 2007 68

M. Thomson Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 69

Hadron Calorimetry (~4 l) Options for Digital HCal: SS or Tungsten / 3 readout technologies Scintillator GEMs RPCs Technology Proven (Si. PM ? ) (Si. PM? ) Relatively new Relatively old Electronic readout Analog (multi-bit) or Semi-digital (few-bit) Digital (single-bit) Thickness (total) ~ 8 mm ~8 mm ~ 8 mm Segmentation 3 x 3 cm 2 1 x 1 cm 2 Pad multiplicity for MIPs Small cross talk Measured at 1. 27 Measured at 1. 6 Sensitivity to neutrons (low energy) Yes Negligible Recharging time Fast? Slow (20 ms/cm 2) Reliability Proven Sensitive Proven (glass) Calibration Challenge Depends on efficiency Not a concern (high efficiency) Assembly Labor intensive Relatively straight forward Simple Cost Not cheap (Si. PM ? ) (Si. PM? ) Expensive foils Cheap J. Repond Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 70

M. Thomson Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 71

Radius vs. Field LDC 00 Sc 100 Ge. V jets 100 Ge. V Jets 180 Ge. V jets «LDC Jet energy performance found to depend mainly on: s HCAL thickness s TPC Radius s B-field Empirical Parametrizations M. Thomson Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 72

Tracking m Tracking for any modern experiment should be conceived as an integrated system, combined optimization of: Ä Ä the inner tracking (vertex detection) the central tracking the forward tracking the integration of the high granularity EM Calorimeter m Pixelated vertex detectors are capable of track reconstruction on their own, as was demonstrated by the 307 Mpixel CCD vertex detector of SLD, and is being planned for the ILC m Track reconstruction in the vertex detector impacts the role of the central and forward tracking system Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 73

Inner Tracking/Vertex Detection for the ILC Detector Requirements m Excellent spacepoint precision ( < 4 microns ) m Superb impact parameter resolution ( 5µm 10µm/(p sin 3/2 ) ) m Transparency ( ~0. 1% X 0 per layer ) m Track reconstruction ( find tracks in VXD alone ) m Sensitive to acceptable number of bunch crossings ( <150 = 45 msec) m EMI immunity m Power Constraint (< 100 Watts) ~ Concepts under Development for International Linear Collider m Charge-Coupled Devices (CCDs) Ä demonstrated in large system (307 Mpx) at SLD, but slow Column Parallel CCDs, FPCCD m Monolithic Active Pixels – CMOS Ä m m MAPs, FAPs, Chronopixels, 3 D-Fermilab DEpleted P-channel Field Effect Transistor (DEPFET) Silicon on Insulator (So. I) Image Sensor with In-Situ Storage (ISIS) HAPS (Hybrid Pixel Sensors) Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 74

Si. D Vertex Layout 5 barrel layers 4 end disks R [cm] Si. D 00 5 T Design drivers: Smallest radius possible Clear pair background Role: Jim Brau Seed tracks & vertexing Improve forward region Physics and Detectors of the International Linear Collider Z= 6. 25 cm Z [cm] Erice, October 9, 2007 75

Column Parallel CCD for ILC SLD Vertex Detector designed to read out 800 kpixels/channel at 10 MHz, operated at 5 MHz => readout time = 200 msec/ch ILC requires faster readout for 300 nsec bunch spacing << 1 msec Possible Solution: Column Parallel Readout LCFI (Bristol, Glasgow, Lancaster, Liverpool, Nijmegen, Oxford, RAL) (Whereas SLD used one readout channel for each 400 columns) Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 76

Image Sensor with In-situ Storage (ISIS) m m EMI concern (SLC experience) motivates delayed operation during beam Robust storage of charge in buried channel during beam passage Ä Ä m Pioneered by W F Kosonocky et al IEEE SSCC 1996, Digest of Technical Papers, 182 T Goji Etoh et al, IEEE ED 50 (2003) 144; runs up to 1 Mfps. ISIS Sensor details: Ä Ä Ä CCD-like charge storage cells in CMOS or CCD technology Processed on sensitive epi layer p+ shielding implant forms reflective barrier (deep implant) Overlapping poly gates not likely to be available, may not be needed Test device built by e 2 v for LCFI Collaboration Reset transistor Source follower Row select transistor photogate transfer storage pixel #1 gate storage output sense reset VDD pixel #20 gate node (n+) gate row to column select load n+ buried channel (n) p+ well p+ shielding implant reflected charge Charge collection High resistivity epitaxial layer (p) Jim Brau substrate (p+) Physics and Detectors of the International Linear Collider reflected charge Erice, October 9 , 2007 77

FPCCD (KEK) ■ Fine-pixel CCD l l l (5 m)2 pixel Fully-depleted to suppress diffusion Immune to EMI CCD is an established technology Baseline for GLD l l l 78 Fully-depleted CCD exists (Hamamatsu : astrophys. ) Background hits can be further reduced by hit pattern (~1/20) No known problems now Prototyping

Monolithic CMOS for Pixel Detector Concept m Standard VLSI chip, with thin, un-doped silicon sensitive layer, operated undepleted R&D m Advantages m m m decoupled charge sensing and signal transfer (improved radiation tolerance, random access, etc. ) small pitch (high tracking precision) Thin, fast readout, moderate price m m m Strasbourg IRe. S has been working on development of monolithic active pixels since 1989; others (RAL, Yale/Or. , etc. ) IRe. S prototype arrays of few thousands pixels demonstrated viability. Large prototypes now fabricated/tested. Attention on readout strategies adapted to specific experimental conditions, and transfer to AMS 0. 35 OPTO from TSMC 0. 25 Ä ~< 12 um epi vs. < 7 um Application to STAR Parallel R&D: m m Jim Brau FAPS (RAL): 10 -20 storage caps/pixel Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 79

Chronopixel (CMOS) Yale/Oregon/Sarnoff m Completed Macropixel design last year Ä Ä Ä Key feature – stored hit times (4 deep) 645 transistors Spice simulation verified design TSMC 0. 18 m ~50 m pixel v v Ä m 90 nm 20 -25 m pixel January, 2007 Ä Ä m Epi-layer only 7 m Talking to JAZZ (15 m epi-layer) Completed design - Chronopixel Deliverable – tape for foundry 563 Transistors Near Future (dependent on funding) Ä Fab 50 m Chronopixel array v Ä 50 um Demonstrate performance Then, 10 -15 m pixel Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 80

3 D/SOI Fermilab Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 81

Inner Tracking/Vertex Detection (DEPFET) Concept m m Properties Field effect transistor on top of fully depleted bulk All charge generated in fully depleted bulk; assembles underneath the transistor channel; steers the transistor current Clearing by positive pulse on clear electrode Combined function of sensor and amplifier m m m 16 x 128 DEPFET-Matrix m m low capacitance ► low noise Signal charge remains undisturbed by readout ► repeated readout Complete clearing of signal charge ► no reset noise Full sensitivity over whole bulk ► large signal for m. i. p. ; X-ray sens. Thin radiation entrance window on backside ► X-ray sensitivity Charge collection also in turned off mode ► low power consumption Measurement at place of generation ► no charge transfer (loss) Operation over very large temperature range ► no cooling needed MPI Munich, MPI Halle, U. Bonn, U. Mannheim Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 82

Central Tracking m Two general approaches being developed for the ILC TPC (GLD, LDC, 4 th) • Builds on successful experience of PEP-4, ALEPH, ALICE, DELPHI, STAR, …. . • Large number of space points, making reconstruction straight-forward • d. E/dx particle ID, bonus • Minimal material, valuable for calorimetry • Tracking up to large radii Silicon (Si. D) • Superb spacepoint precision allows tracking measurement goals to be achieved in a compact tracking volume • Robust to spurious, intermittent backgrounds • ILC is not a storage ring Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 83

Central Tracking with TPC Issues for an ILC TPC m Optimize novel gas amplification systems Ä Conventional TPC readout based on MWPC and pads v Ä Improvement by replacing MWPC readout with micropattern gas chambers (eg. GEMs, Micromegas, Medipix) v v m m m limited by positive ion feedback and MWPC response Small structures (no E B effects) 2 -D structures Only fast electron signal Intrinsic ion feedback suppression e+e- pairs in 40 msec hadrons in 40 msec Neutron and gamma backgrounds (~130 bunch crossings) Optimize single point and double track resolution Performance in high magnetic fields Demonstrate large system performance with control of systematics Minimize impact of endplate Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 84

Central Tracking with Silicon Expecting the machine backgrounds (esp. beam loss occurrences) of the ILC to be erratic (based on SLC experience), robustness of silicon is very attractive. single bunch timing The Si. D barrel tracking is baselined as 5 layers of pixellated vertex detector and 5 layers of Si strip detectors (in ~10 cm segments) going out to 1. 25 meters With superb position resolution, compact tracker which achieves the linear collider tracking resolution goals is possible Compact tracker makes the calorimeter smaller and therefore cheaper, permitting more aggressive technical choices (assuming cost constraint) Silicon tracking layer thickness determines low momentum performance Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 85

SID 00 Tracking • Closed CF/Rohacell cylinders • Nested support via annular rings • Power/readout motherboard mounted on support rings • Cylinders tiled with 10 x 10 cm sensors with readout chip • Single sided (f) in barrel • R, f in disks • Modules mainly silicon with minimal support (0. 8% X 0) • Overlap in phi and z Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 86

Material Budget of Silicon Tracker ~ 0. 8 %/layer at normal incidence Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 87

Robust Pattern Recognition with Silicon m t tbar event in VXD w/ backgrounds from 150 bunch crossings - BUT 1 billion pixels! clean detection with time stamping Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 88

Excellent momentum resolution with Silicon SDAUG 05: 5 T, R=125 cm SD PETITE: 5 T, R=100 cm LOW FIELD: 4 T, R=125 cm At 90 o 0. 5% Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9, 2007 89

DID (Detector-Integrated Dipole) ■ Xing angle (w/o correction) l l beam sees Btranseverse of solenoid → spiral e+ B e. Still head-on (mod xing angle) ? ◆ ◆ Yes for e+e-. No for e-e-. e+ee-e- Problems still for e+e- : ◆ ◆ SR emittance growth (significant in some cases) Polarization vector rotation (minor problem? ) 90

DID and anti-DID Align B with incoming e+/e- beams (on av. ) - DID e+ e. B B • Solves SR emittance growth • 2 Bt for outgoing beams worse pair background Align B with outgoing e+/e- beams (on av. ) - anti DID e+ B B • Pair background ~ 0 mrad xing angle • 2 Bt for incoming beams worse for SR emittance growth ~OK for 14 mrad 91 e- DID or anti. DID, not both simultaneouly

Single IR with Push-Pull Detectors m Large cost saving compared with 2 IR Ä m ~200 M$ compared with 2 IR with crossing angles 14/14 mrad Push-pull detectors Ä Ä Task force of WWS and GDE studied issues Initial conclusion: No show-stopper v But need careful design and R&D v — For example, need quick switch-over v Jim Brau 2 IR should be kept as an ‘Alternative’ Physics and Detectors of the International Linear Collider Erice, October 9, 2007 92

Concept of IR hall with two detectors The concept is evolving and details being worked out may be accessible during run detector A accessible during run detector B A. Jim Seryi, Feb 4, 2007, and Beijing Brau Physics Detectors of the International Linear Collider Platform for electronic and services (~10*8*8 m). Shielded (~0. 5 m of concrete) from five sides. Moves with detector. Also provide vibration isolation. Erice, October 9, 2007 93

Energy Measurement ■ Goal: l ■ 100 ppm (10 -4) absolute energy measurement Baseline: l l 1 upstream + 1 downstream spectrometers / beam BPM Upstream spectrometer ◆ ◆ l 4 -magnet chicane + RF BPMs 1 mm offset + =100 nm: 10 -4 BPM Downstream spectrometer ◆ 3 -magnet chicane w/wigglers + SR photon detectors 94 Wiggler SR detector

Polarization Measurement ■ Goal : l ■ 0. 25% accuracy (particularly on Z) Baseline : l l 1 upstream + 1 downstrem polarimeters / beam Compton polarimeter Shoot circularly-polarized photon at the electron beam at a focus. ◆ Measure the compton-scattered electron. ◆ Polarization vector at IP = that at the polarimeter → beam direction at IP parallel to that at the polarimeter ◆ 4 -magnet chicane ◆ 95

Luminosity Measurement ■ ■ Accuracy goal : 10 -3 or better absolute Detector : LUMCAL(LUMMON/FCAL) l l l ■ ~30 -90 mrad ~10 Bhabhas / bunch train Default: Si-W calorimeter R&D required ◆ ◆ ◆ ■ The precision achievable for different xing angles? Careful systematics studies. 10 -4 desirable for Giga-Z, larger polar angles? Backgrounds from pairs etc. ? ‘Physics’ events (central detector) : l Acollinear Bhabha Luminosity spectrum, etc. 96

Organization m World Wide Study (WWS) Ä Ä Ä Formed in 1998 (Vancouver ICHEP) 18 member organizing committee - 6/region Co-chairs v v v Ä v v v H. Yamamoto F. Richard J. Brau Recognize and coordinate detector concept studies Register and coordinate detector R&Ds Interface with GDE Organize LCWS (International Linear Collider Workshop, 1 per year now) Research Director Ä Ä Jim Brau S. Komamiya D. Miller C. Baltay Tasks v m http: //physics. uoregon. edu/~lc/wwstudy S. Yamada appointed by ILCSC - fall 2007 WWS co-chairs advising Forming International Detector Advisory Group Coordinating with GDE Directorate Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 97

The GDE Plan and Schedule 2005 2006 2007 2008 2009 2010 Global Design Effort Baseline configuration Detector Outline Document Jim Brau Reference Design Detector Concept Report (issued w/ RDR) Project LHC Physics Engineering Design ILC R&D Program Bids to Host; Site Selection; Physics and Detectors of the International Linear Collider International Mgmt Erice, October 9 , 2007

Detector Roadmap (not yet fully implemented) • 2007 – Writing of Physics and Detector volumes (2 vol. of RDR) Call for Letters of Intent from Detector groups ILCSC, Research Director • 2008 – Letters of Intent received by ILCSC, RD International Detector Advisory Group reviews LOIs Guides community to the definition of two detectors for EDR preparation Collaborations formed to develop EDRs • 2009 -2011 – Development of two engineered designs, produce first engineering design reports (EDRs) for the two overall detectors, NOTE - THESE EFFORTS NEED NOT REPRESENT THE FINAL SELECTION OF DETECTORS FOR THE ILC EXPERIMENTAL PROGRAM 99 WWS

Conclusion m Current status of Electroweak Precision measurements indicates the physics at the LHC and ILC will be rich m The International Linear Collider will be a powerful tool m DISCOVERY OPPORTUNITIES at the ILC will be limited by detector performance Electroweak Symmetry Breaking origin of mass other fundamental physics advance understanding of LHC discoveries advances different from LHC required program of ILC Detector R&D is developing these capabilities Jim Brau Physics and Detectors of the International Linear Collider Erice, October 9 , 2007 100