Future Lepton Collider 1 Barry Barish Czech Technical University 15-Nov-11 The Future of Accelerator Based Particle Physics 15-Nov-11 Czech Technical University Path to higher energy Collider History: Energy constantly increasing with time o Hadron Collider at the energy frontier o Lepton Collider for precision physics Consensus to build Linear Collider with E cm > 500 GeV to complement LHC physics 15-Nov-11 Czech Technical University Future Lepton Collider 2 15-Nov-11 Czech Technical University Future Lepton Collider 33 Three Generations: Complementarity Discovery Of Charm Particles and 3.1 GeV Burt Richter Nobel Prize SPEAR at SLAC First generation 15-Nov-11 Czech Technical University Future Lepton Collider 44 Rich History of Discovery DESY PETRA Collider Second generation Future Lepton Collider 55 Precision Measurements CERNs LEP Collider set the stage for Terascale physics Reveal the origin of quark and lepton mass Produce dark matter in the laboratory Test exotic theories of space and time Third generation 15-Nov-11 Czech Technical University Future Lepton Collider 66 SPEAR PETRA LEP ENERGY YEAR TeV ILC (or CLIC) GeV Fourth generation? Three Generations of Successful e + e - Colliders The Energy Frontier 15-Nov-11 Czech Technical University Future Lepton Collider 77 The next big accelerator: a lepton collider? Terascale science and how a lepton collider will complement the LHC? Electron-Positron: Why linear? What technology to employ? An option with muons? Designing the ILC -- a new paradigm in international collaboration. A thumbnail description of the ILC Reference Design and Cost? Present program and plans 15-Nov-11 Czech Technical University Future Lepton Collider 88 Exploring the Terascale The Tools The LHC It will lead the way and has large reach Quark-quark, quark-gluon and gluon-gluon collisions at TeV Broadband initial state The ILC A second view with high precision Electron-positron collisions with fixed energies, adjustable between 0.1 and 1.0 TeV Well defined initial state Together, these are our tools for the Terascale 15-Nov-11 Czech Technical University Future Lepton Collider 99 Why e + e - Collisions? Elementary particles Well-defined energy angular momentum Uses full COM energy Produces particles democratically Can mostly fully reconstruct events 15-Nov-11 Czech Technical University Future Lepton Collider 10 Comparison: ILC and LHC ILC LHC Beam Particle : Electron x Positron Proton x Proton CMS Energy : 0.5 1 TeV 14 TeV Luminosity Goal : 2 x /cm 2 /sec 1 x10 34 /cm 2 /sec Accelerator Type : Linear Circular Storage Rings Technology : Supercond. RF Supercond. Magnet 15-Nov-11 Czech Technical University Future Lepton Collider 11 LHC ILC e + e Z H Z e + e , H b Higgs event Simulation Comparison 15-Nov-11 Czech Technical University Future Lepton Collider 12 Higgs Signal with LHC Rare decay channel: BR~10 -3 Projected signal and background after data cuts to optimize signal to background Background large: S/B 1:20, but can estimate from non signal areas CMS 15-Nov-11 Czech Technical University Future Lepton Collider 13 Precision Higgs physics Model-independent Studies mass absolute branching ratios total width spin top Yukawa coupling self coupling Precision Measurements Garcia-Abia et al 15-Nov-11 Czech Technical University Future Lepton Collider 14 Higgs Coupling-mass relation Remember - the Higgs is a Different! It is a zero spin particle that fills the vacuum It couples to mass; masses and decay rates are related 15-Nov-11 Czech Technical University Future Lepton Collider 15 The linear collider will measure the spin of any Higgs it can produce by measuring the energy dependence from threshold ILC: Is it really the Higgs ? Measure the quantum numbers. The Higgs must have spin zero ! 15-Nov-11 Czech Technical University Future Lepton Collider 16 What can we learn from the Higgs? Precision measurements of Higgs coupling Higgs Coupling strength is proportional to Mass 15-Nov-11 Czech Technical University Future Lepton Collider 17 e + e - : Studying the Higgs determine the underlying model SM 2HDM/MSSM Yamashita et al Zivkovic et al 15-Nov-11 Czech Technical University Future Lepton Collider 18 - Measure quantum numbers - Is it MSSM, NMSSM, ? - How is it broken? ILC can answer these questions! -tunable energy -polarized beams Supersymmetry at ILC e + e - production crosssections 15-Nov-11 Czech Technical University Future Lepton Collider 19 ILC Supersymmetry Two methods to obtain absolute sparticle masses: In the continuumKinematic Threshold: Minimum and maximum determines masses of primary slepton and secondary neutralino/chargino Determine SUSY parameters without model assumptions Martyn Freitas 15-Nov-11 Czech Technical University Future Lepton Collider 20 The abundance of the LSP as dark matter can be precisely calculated, if the mass and particle species are given. ILC can precisely measure the mass and the coupling of the LSP The Dark Matter density in the universe and in our Galaxy can be calculated. The most attractive candidate for the dark matter is the lightest SUSY particle Dark Matter Candidates LSP 15-Nov-11 Czech Technical University Future Lepton Collider 21 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 ? 15-Nov-11 Czech Technical University Future Lepton Collider 22 Possible TeV Scale Lepton Colliders ILC < 1 TeV Technically possible ~ QUAD POWER EXTRACTION STRUCTURE BPM ACCELERATING STRUCTURES CLIC < 3 TeV Feasibility? Longer timescale Main beam 1 A, 200 ns from 9 GeV to 1.5 TeV Drive beam - 95 A, 300 ns from 2.4 GeV to 240 MeV Muon Collider < 4 TeV FEASIBILITY?? Much longer timescale Much R&D Needed Neutrino Factory R&D + bunch merging much more cooling etc ILC CLIC Muon Collider 15-Nov-11 Czech Technical University Future Lepton Collider 23 ILC Baseline Design Gev e+ e- Linear Collider Energy 250 Gev x 250 Gev Length km # of RF units 560 # of cryomodules1680 # of 9-cell cavities Detectors push-pull 2e34 peak luminosity 5 Hz rep rate, > 6000 bunches per cycle IP spots sizes: x 350 620 nm; y 3.5 9.0 nm 15-Nov-11 Czech Technical University Future Lepton Collider 24 RDR Design Parameters Max. Center-of-mass energy500GeV Peak Luminosity~2x /cm 2 s Beam Current9.0mA Repetition rate5Hz Average accelerating gradient31.5MV/m Beam pulse length0.95ms Total Site Length31km Total AC Power Consumption~230MW Future Lepton Collider 25 E ~ (E 4 /m 4 R) Linear implies single pass cost Energy Circular Collider Linear Collider R Synchrotron Radiation R ~ 200 GeV < 5 nm vertical Low emittance (high brightness) machine optics Contain emittance growth Squeeze the beam as small as possible at collision point 15-Nov-11 Czech Technical University Future Lepton Collider 26 ILC Underlying Technology Room temperature copper structures OR Superconducting RF cavities 15-Nov-11 Czech Technical University Future Lepton Collider 27 SCRF Technology Recommendation The recommendation of ITRP was presented to ILCSC & ICFA on August 19, 2004 in a joint meeting in Beijing. 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). This led to the formation of the Global Design Effort (GDE) ICFA unanimously endorsed the ITRPs recommendation on August 20, 2004 Strong international interest in developing SCRF technology 15-Nov-11 Czech Technical University Future Lepton Collider 28 GDE -- Designing a Linear Collider Superconducting RF Main Linac Traveling wave structures NC standing wave structures would have high Ohmic losses => traveling wave structures RF flows with group velocity v G along the structure into a load at the structure exit Condition for acceleration: =d/c ( cell phase difference) Shorter fill time T fill = 1/v G dz - order