The International Linear Collider Barry Barish iThemba Cape Town 21-Oct-05

25-Oct-05iThemba ILC Seminar2 Particle Physics Inquiry Based Science 1.Are there undiscovered principles of nature: New symmetries, new physical laws? 2.How can we solve the mystery of dark energy? 3.Are there extra dimensions of space? 4.Do all the forces become one? 5.Why are there so many kinds of particles? 6.What is dark matter? How can we make it in the laboratory? 7.What are neutrinos telling us? 8.How did the universe come to be? 9.What happened to the antimatter? from the Quantum Universe

25-Oct-05iThemba ILC Seminar3 Answering the Questions Three Complementary Probes Neutrinos as a Probe –Particle physics and astrophysics using a weakly interacting probe High Energy Proton Proton Colliders –Opening up a new energy frontier ( ~ 1 TeV scale) High Energy Electron Positron Colliders –Precision Physics at the new energy frontier

25-Oct-05iThemba ILC Seminar4 Puzzle resolved … neutrinos oscillate SNO (Canada) used D 2 0 to detect other neutrino types KamLAND used terrestrial neutrinos from reactors, observes oscillations

25-Oct-05iThemba ILC Seminar5 Neutrinos – The Future Long baseline neutrino experiments – Create neutrinos at an accelerator or reactor and study at long distance when they have oscillated from one type to another. MINOS

25-Oct-05iThemba ILC Seminar6 Neutrinos – The Big Questions Why are neutrino masses so small ? Are the neutrinos their own antiparticles? What is the separation and ordering of the masses of the neutrinos? Neutrinos contribution to the dark matter? CP violation in neutrinos, leptogenesis, possible role in the early universe and in understanding the particle antiparticle asymmetry in nature?

25-Oct-05iThemba ILC Seminar7 Why a TeV Scale e + e - Accelerator? Two parallel developments over the past few years ( the science & the technology) –The precision information from LEP and other data have pointed to a low mass Higgs; Understanding electroweak symmetry breaking, whether supersymmetry or an alternative, will require precision measurements. –There are strong arguments for the complementarity between a ~ TeV ILC and the LHC science.

25-Oct-05iThemba ILC Seminar8 Electroweak Precision Measurements What causes mass?? The mechanism – Higgs or alternative appears around the corner

25-Oct-05iThemba ILC Seminar9 Accelerators and the Energy Frontier Large Hadron Collider CERN – Geneva Switzerland

25-Oct-05iThemba ILC Seminar10 LHC and the Energy Frontier Source of Particle Mass The Higgs Field Discover the Higgs or variants or ??? fb -1 LEP FNAL

25-Oct-05iThemba ILC Seminar11 LHC and the Energy Frontier A New Force in Nature Discover a new heavy particle, Z’ Can show by measuring the couplings with the ILC how it relates to other particles and forces

25-Oct-05iThemba ILC Seminar12 Why e + e - Collisions ? elementary particles well-defined –energy, –angular momentum uses full COM energy produces particles democratically can mostly fully reconstruct events

25-Oct-05iThemba ILC Seminar13 Parameters for the ILC E cm adjustable from 200 – 500 GeV Luminosity  ∫ Ldt = 500 fb -1 in 4 years Ability to scan between 200 and 500 GeV Energy stability and precision below 0.1% Electron polarization of at least 80% The machine must be upgradeable to 1 TeV

25-Oct-05iThemba ILC Seminar14 Designing a Linear Collider Superconducting RF Main Linac

25-Oct-05iThemba ILC Seminar15 Electron Positron Colliders The Energy Frontier

25-Oct-05iThemba ILC Seminar16 The linear collider will measure the spin of any Higgs it can produce by measuring the energy dependence from threshold How do you know you have discovered the Higgs ? Measure the quantum numbers. The Higgs must have spin zero !

25-Oct-05iThemba ILC Seminar17 What can we learn from the Higgs? Straight blue line gives the standard model predictions. Range of predictions in models with extra dimensions -- yellow band, (at most 30% below the Standard Model The red error bars indicate the level of precision attainable at the ILC for each particle Precision measurements of Higgs coupling can reveal extra dimensions in nature

25-Oct-05iThemba ILC Seminar18 New space-time dimensions can be mapped by studying the emission of gravitons into the extra dimensions, together with a photon or jets emitted into the normal dimensions. Linear collider Direct production from extra dimensions ?

25-Oct-05iThemba ILC Seminar19 Is there a new symmetry in nature? Supersymmetry The breaking of the symmetry between electromagnetic and weak interactions though the Higgs mechanism introduces several anomalies, which point towards physics beyond the standard model. A particularly attractive scenario is supersymmetry (SUSY), which would eliminates the anomalies from the Higgs section and predicts SUSY partners for all known particles. These particles should be detected at the LHC and ILC

25-Oct-05iThemba ILC Seminar20 The ILC and the Energy Frontier International Linear Collider

25-Oct-05iThemba ILC Seminar21 Superconducting RF Cavities High Gradient Accelerator 35 MV/meter km linear collider

25-Oct-05iThemba ILC Seminar22 Improved Processing Electropolishing Chemical Polish Electro Polish

25-Oct-05iThemba ILC Seminar23 How Costs Scale with Gradient? Relative Cost Gradient MV/m 35MV/m is close to optimum Japanese are still pushing for MV/m 30 MV/m would give safety margin C. Adolphsen (SLAC)

25-Oct-05iThemba ILC Seminar24 Cavity Fabrication

25-Oct-05iThemba ILC Seminar25 Improved Fabrication

25-Oct-05iThemba ILC Seminar26 Improved Processing Electropolishing

25-Oct-05iThemba ILC Seminar27 (Improve surface quality -- pioneering work done at KEK) BCPEP Several single cell cavities at g > 40 MV/m 4 nine-cell cavities at ~35 MV/m, one at 40 MV/m Theoretical Limit 50 MV/m Electro-polishing

25-Oct-05iThemba ILC Seminar28 Baseline Gradient

25-Oct-05iThemba ILC Seminar29 Improved Cavity Shapes

25-Oct-05iThemba ILC Seminar30 Large Grain Single Crystal Nb Material

Internationl Linear Collider Timeline Global Design EffortProject Baseline configuration Reference Design ILC R&D Program Technical Design Expression of Interest to Host International Mgmt

25-Oct-05iThemba ILC Seminar32 Conclusions We have determined a number of very fundamental physics questions to answer, like …. –What determines mass? –What is the dark matter? –Are there new symmetries in nature? –What explains the baryon asymmetry? –Are the forces of nature unified We are developing the tools to answer these questions and discover new ones –Neutrino Physics –Large Hadron Collider –International Linear Collider The next era of particle physics will be very exciting