The International Linear Collider Barry Barish 9 Nov05

The International Linear Collider Barry Barish 9 -Nov-05 LAL Orsay Seminar

Particle Physics Inquiry Based Science 1. Are there undiscovered principles of nature: New symmetries, new physical laws? 2. 3. 4. 5. 6. How can we solve the mystery of dark energy? Are there extra dimensions of space? Do all the forces become one? Why are there so many kinds of particles? 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? 9 -Nov-05 LAL Orsay Seminar from the Quantum Universe 2

Answering the Questions Three Complementary Probes • Neutrinos as a Probe – Particle physics and astrophysics using a weakly interacting probe • High Energy Proton Colliders – Opening up a new energy frontier ( ~ 1 Te. V scale) • High Energy Electron Positron Colliders – Precision Physics at the new energy frontier 9 -Nov-05 LAL Orsay Seminar 3

Neutrinos observed from the sun ! 41 H 4 He + 2 e+ + 2 ve + energy Koshiba Davis and Bahcall 9 -Nov-05 LAL Orsay Seminar Super. Kamiokande 4

But, too few neutrinos … If neutrinos have mass, then as conjectured earlier by Bruno Pontecorvo, neutrinos could “oscillate” from one type to another. In this case, some of the original electron neutrinos made in the sun convert to other neutrinos on trajectory to the earth 9 -Nov-05 LAL Orsay Seminar 5

Puzzle resolved … neutrinos oscillate SNO (Canada) used D 20 to detect other neutrino types 9 -Nov-05 Kam. LAND used terrestrial neutrinos from reactors, observes oscillations LAL Orsay Seminar 6

Neutrinos – Some of the Dark Matter! Dark Energy Cold Dark Matter 20% 70% Hot Dark Matter (neutrinos) < 5% Ordinary (baryonic) Matter 5% 9 -Nov-05 LAL Orsay Seminar 7

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 Opera 9 -Nov-05 LAL Orsay Seminar 8

Neutrinos – Many 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? 9 -Nov-05 LAL Orsay Seminar 9

Why a Te. V 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 ~0. 5 -1. 0 Te. V ILC and the LHC science. 9 -Nov-05 LAL Orsay Seminar 10

Electroweak Precision Measurements What causes mass? ? The mechanism – Higgs or alternative appears around the corner 9 -Nov-05 LAL Orsay Seminar 11

Accelerators and the Energy Frontier Large Hadron Collider CERN – Geneva Switzerland 9 -Nov-05 LAL Orsay Seminar 12

LHC and the Energy Frontier Source of Particle Mass Discover the Higgs The Higgs Field LEP fb-1 FNAL or variants or ? ? ? 9 -Nov-05 LAL Orsay Seminar 13

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 9 -Nov-05 LAL Orsay Seminar 14

This led to higher energy machines: Electron-Positron Colliders ADA Bruno Touschek built the first successful electron-positron collider at Frascati, Italy (1960) Eventually, went up to 3 Ge. V 9 -Nov-05 LAL Orsay Seminar 15

But, not quite high enough energy …. 3. 1 Ge. V and Discovery Of Charm Particles SPEAR at SLAC 9 -Nov-05 Burt Richter Nobel Prize LAL Orsay Seminar 16

The rich history for e+e- continued as higher energies were achieved … DESY PETRA Collider 9 -Nov-05 LAL Orsay Seminar 17

Electron Positron Colliders The Energy Frontier 9 -Nov-05 LAL Orsay Seminar 18

Why e+e- Collisions ? • elementary particles • well-defined – energy, – angular momentum • uses full COM energy • produces particles democratically • can mostly fully reconstruct events 9 -Nov-05 LAL Orsay Seminar 19

How do you know you have discovered the Higgs ? Measure the quantum numbers. The Higgs must have spin zero ! The linear collider will measure the spin of any Higgs it can produce by measuring the energy dependence from threshold 9 -Nov-05 LAL Orsay Seminar 20

What can we learn from the Higgs? Precision measurements of Higgs coupling can reveal extra dimensions in nature • 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 9 -Nov-05 LAL Orsay Seminar 21

Direct production from extra dimensions ? Linear collider 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. 9 -Nov-05 LAL Orsay Seminar 22

Is There a New Symmetry in Nature? Supersymmetry Bosons Fermions Virtues of Supersymmetry: – Unification of Forces – The Hierarchy Problem – Dark Matter … 9 -Nov-05 LAL Orsay Seminar 23

Parameters for the ILC • Ecm adjustable from 200 – 500 Ge. V • Luminosity ∫Ldt = 500 fb-1 in 4 years • Ability to scan between 200 and 500 Ge. V • Energy stability and precision below 0. 1% • Electron polarization of at least 80% • The machine must be upgradeable to 1 Te. V 9 -Nov-05 LAL Orsay Seminar 24

A Te. V Scale e+e- Accelerator? • Two parallel developments over the past few years (the science & the technology) – Two alternate designs -- “warm” and “cold” had come to the stage where the show stoppers had been eliminated and the concepts were well understood. – A major step toward a new international machine requires uniting behind one technology, and then make a unified global design based on the recommended technology. 9 -Nov-05 LAL Orsay Seminar 25

GLC GLC/NLC Concept • The JLC-X and NLC essentially a unified single design with common parameters • The main linacs based on 11. 4 GHz, room temperature copper technology. 9 -Nov-05 LAL Orsay Seminar 26

TESLA Concept • The main linacs based on 1. 3 GHz superconducting technology operating at 2 K. • The cryoplant, is of a size comparable to that of the LHC, consisting of seven subsystems strung along the machines every 5 km. 9 -Nov-05 LAL Orsay Seminar 27

Drive Beam CLIC Concept The main linac rf power is produced by decelerating a highcurrent (150 A) lowenergy (2. 1 Ge. V) drive beam Main Accelerator Nominal accelerating gradient of 150 MV/m GOAL Proof of concept ~2010 9 -Nov-05 LAL Orsay Seminar 28

SCRF Technology Recommendation • The recommendation of ITRP was presented to ILCSC & ICFA on August 19, 2004 in a joint meeting in Beijing. • ICFA unanimously endorsed the ITRP’s recommendation on August 20, 2004 9 -Nov-05 LAL Orsay Seminar 29

The ITRP Recommendation • We recommend that the linear collider be based on superconducting rf technology – This recommendation is made with the understanding that we are recommending a technology, not a design. We expect the final design to be developed by a team drawn from the combined warm and cold linear collider communities, taking full advantage of the experience and expertise of both (from the Executive Summary). 9 -Nov-05 LAL Orsay Seminar 30

The Community Self-Organized Nov 13 -15, 2004 9 -Nov-05 LAL Orsay Seminar 31

Global Design Effort – The Mission of the GDE • Produce a design for the ILC that includes a detailed design concept, performance assessments, reliable international costing, an industrialization plan , siting analysis, as well as detector concepts and scope. • Coordinate worldwide prioritized proposal driven R & D efforts (to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc. ) 9 -Nov-05 LAL Orsay Seminar 32

GDE Members Chris Adolphsen, SLAC Jean-Luc Baldy, CERN Philip Bambade, LAL, Orsay Barry Barish, Caltech Wilhelm Bialowons, DESY Grahame Blair, Royal Holloway Jim Brau, University of Oregon Karsten Buesser, DESY Elizabeth Clements, Fermilab Michael Danilov, ITEP Jean-Pierre Delahaye, CERN, Gerald Dugan, Cornell University Atsushi Enomoto, KEK Brian Foster, Oxford University Warren Funk, JLAB Jie Gao, IHEP Terry Garvey, LAL-IN 2 P 3 Hitoshi Hayano, KEK Tom Himel, SLAC Bob Kephart, Fermilab Eun San Kim, Pohang Acc Lab Hyoung Suk Kim, Kyungpook Nat’l Univ Shane Koscielniak, TRIUMF Vic Kuchler, Fermilab Lutz Lilje, DESY Tom Markiewicz, SLAC David Miller, Univ College of London Shekhar Mishra, Fermilab Youhei Morita, KEK Olivier Napoly, CEA-Saclay Hasan Padamsee, Cornell University Carlo Pagani, DESY Nan Phinney, SLAC Dieter Proch, DESY Pantaleo Raimondi, INFN Tor Raubenheimer, SLAC Francois Richard, LAL-IN 2 P 3 Perrine Royole-Degieux, GDE/LAL Kenji Saito, KEK Daniel Schulte, CERN Tetsuo Shidara, KEK Sasha Skrinsky, Budker Institute Fumihiko Takasaki, KEK Laurent Jean Tavian, CERN Nobu Toge, KEK Nick Walker, DESY Andy Wolski, LBL Hitoshi Yamamoto, Tohoku Univ Kaoru Yokoya, KEK Americas 16 Europe 21 Asia 12 9 -Nov-05 49 members LAL Orsay Seminar 33

Designing a Linear Collider Superconducting RF Main Linac 9 -Nov-05 LAL Orsay Seminar 34

Specific Machine Realizations rf bands: RF Bands 1. 3 S-band (SLAC linac) 2. 856 GHz 1. 7 cm C-band (JLC-C) 5. 7 GHz 0. 95 cm X-band (NLC/GLC) 11. 4 GHz 0. 42 cm 25 -30 GHz 0. 2 cm (CLIC) GHz l = L-band (TESLA) 3. 7 cm Accelerating structure size is dictated by wavelength of the rf accelerating wave. Wakefields related to structure size; thus so is the difficulty in controlling emittance growth and final luminosity. Ø Bunch spacing, train length related to rf frequency Ø Damping ring design depends on bunch length, hence frequency Frequency dictates many of the design issues for LC 9 -Nov-05 LAL Orsay Seminar 35

Design Approach • Create a baseline configuration for the machine – Document a concept for ILC machine with a complete layout, parameters etc. defined by the end of 2005 – Make forward looking choices, consistent with attaining performance goals, and understood well enough to do a conceptual design and reliable costing by end of 2006. – Technical and cost considerations will be an integral part in making these choices. – Baseline will be put under “configuration control, ” with a defined process for changes to the baseline. – A reference design will be carried out in 2006. I am proposing we use a “parametric” design and costing approach. – Technical performance and physics performance will be evaluated for the reference design 9 -Nov-05 LAL Orsay Seminar 36

Parametric Approach • Parametric approach to design – machine parameters : a space to optimize the machine – Trial parameter space, being evaluated by subsystems – machine design : incorporate change without redesign; incorporates value engineering, trade studies at each step to minimize costs 9 -Nov-05 LAL Orsay Seminar 37

Approach to ILC R&D Program • Proposal-driven R&D in support of the baseline design. – Technical developments, demonstration experiments, industrialization, etc. • Proposal-driven R&D in support of alternatives to the baseline – Proposals for potential improvements to the baseline, resources required, time scale, etc. • Develop a prioritized DETECTOR R&D program aimed at technical developments needed to reach combined design performance goals 9 -Nov-05 LAL Orsay Seminar 38

The Key Decisions Critical choices: luminosity parameters & gradient 9 -Nov-05 LAL Orsay Seminar 39

Making Choices – The Tradeoffs Many decisions are interrelated and require input from several WG/GG groups 9 -Nov-05 LAL Orsay Seminar 40

Superconducting RF Cavities High Gradient Accelerator 35 MV/meter -- 40 km linear collider 9 -Nov-05 LAL Orsay Seminar 41

Improved Cavity Shapes 9 -Nov-05 LAL Orsay Seminar 42

Improved Fabrication 9 -Nov-05 LAL Orsay Seminar 43

Improved Processing Electropolishing Chemical Polish Electro Polish 9 -Nov-05 LAL Orsay Seminar 44

Electro-polishing (Improve surface quality -- pioneering work done at KEK) BCP EP • 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 9 -Nov-05 LAL Orsay Seminar 45

single-cell measurements (in nine-cell cavities) Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) 9 -Nov-05 LAL Orsay Seminar 46

Baseline Gradient 9 -Nov-05 LAL Orsay Seminar 47

Large Grain Single Crystal Nb Material 9 -Nov-05 LAL Orsay Seminar 48

ILC Siting and Conventional Facilities • The design is intimately tied to the features of the site – 1 tunnels or 2 tunnels? – Deep or shallow? – Laser straight linac or follow earth’s curvature in segments? • GDE ILC Design will be done to samples sites in the three regions – North American sample site will be near Fermilab – Japan and Europe are to determine sample sites by the end of 2005 9 -Nov-05 LAL Orsay Seminar 49

1 vs 2 Tunnels • Tunnel must contain – Linac Cryomodule – RF system – Damping Ring Lines • Save maybe $0. 5 B • Issues – Maintenance – Safety – Duty Cycle 9 -Nov-05 LAL Orsay Seminar 50

Possible Tunnel Configurations • 9 -Nov-05 One tunnel of two, with variants ? ? LAL Orsay Seminar 51

ILC Civil Program Civil engineers from all three regions working to develop methods of analyzing the siting issues and comparing sites. The current effort is not intended to select a potential site, but rather to understand from the beginning how the features of sites will effect the design, performance and cost 9 -Nov-05 LAL Orsay Seminar 52

Beam Detector Interface Tauchi LCWS 05 9 -Nov-05 LAL Orsay Seminar 53

ACFA Joint Linear Collider Physics and Detector Working Group • “Our task is to continue studies on physics at the linear collider more precisely and more profoundly, taking into account progresses in our field, as well as on developments of detector technologies best suited for the linear collider experiment. As we know from past experiences, this will be enormously important to realize the linear collider. ” • Akiya Miyamoto 9 -Nov-05 LAL Orsay Seminar 54

Accelerator Physics Challenges • Develop High Gradient Superconducting RF systems – Requires efficient RF systems, capable of accelerating high power beams (~MW) with small beam spots(~nm). • Achieving nm scale beam spots – Requires generating high intensity beams of electrons and positrons – Damping the beams to ultra-low emittance in damping rings – Transporting the beams to the collision point without significant emittance growth or uncontrolled beam jitter – Cleanly dumping the used beams. • Reaching Luminosity Requirements – Designs satisfy the luminosity goals in simulations – A number of challenging problems in accelerator physics and technology must be solved, however. 9 -Nov-05 LAL Orsay Seminar 55

Test Facility at KEK 9 -Nov-05 LAL Orsay Seminar 56

Test Facility at SLAC 9 -Nov-05 LAL Orsay Seminar 57

TESLA Test Facility Linac - DESY e- beam diagnostics undulator photon beam diagnostics 240 Me. V 9 -Nov-05 bunch compressor superconducting accelerator modules 120 Me. V LAL Orsay Seminar e- beam diagnostics laser driven electron gun preaccelerator 16 Me. V 4 Me. V 58

Fermilab ILC SCRF Program 9 -Nov-05 LAL Orsay Seminar 59

Internationl Linear Collider Timeline 2005 2006 2007 2008 2009 2010 Global Design Effort Project Baseline configuration Reference Design Technical Design ILC R&D Program Expression of Interest to Host International Mgmt 9 -Nov-05 LAL Orsay Seminar

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 9 -Nov-05 LAL Orsay Seminar 61