Opportunities at the International Linear Collider (ILC ) Nigel Lockyer, University of Pennsylvania Ettore Majorana, Erice, Sicily, September 3, 2006 Columbium or is it Niobium US or Europe? ILC in Japan?

Particle Physics Progress 21 th Century Are We Close to the Top? Physicists want a grand View of the landscape String theorist Burt Ovrut hanging from a rope

The Progress –Standard model of particle physics is a triumph of 20 th century physics –Standard Electroweak model describes all measurements to O(0.1%) –MUST add pure EWK radiative corrections sensitive to mass of the top quark in order for results to be consistent –Standard Model is a gauge theory  massless particles –Electroweak symmetry breaking gives mass to W, Z, quarks and leptons –The EW precision measurements (LEP/SLC+Tevatron) favor a fundamental scalar at low mass (HIGGS) –Unstable quantum corrections to Higgs mass tells us new physics at energy scales of O(1 TeV) needed to stabilize Higgs mass…. Goal: Explore TeV Energy Range

Precision Electroweak Tests of SM Z-line shape Invisible Width N =  Number of light neutrino species: Many of the uncertainties at the level of one part per thousand Z mass 2,000 th of 1%!

A Successful Pattern of Hadron Colliders Complementing e+e- Colliders UA1 and UA2 discovered the W and Z bosons at a hadron collider LEP approved before Z discovered LEP/SLC moved Particle Physics well beyond UA1/UA2 Discovery LEP searches and precision measurements eliminated many models eg. Leptoquarks 3 families of neutrinos Minimal SUSY (MSSM) still consistent with all the data, hence it is still the most possible extension of the standard model Top Discovery at Tevatron (CDF & D0) We have “great confidence” that a Higgs exists or something that performs that function at the TeV scale “Higgs must exist” Susskind, Erice 2006

Motivating Questions 1.Are there undiscovered new symmetries or laws in nature? 2.Are there extra dimensions of space? 3.Do all the forces become one? 4.How can we solve the mystery of Dark Energy? 5.What is Dark Matter? 6.What happened to the anti-matter?

Evolution of Accelerators 9km/13cm = 69,231 14TeV/80keV = 175,000,000 Technology of accelerators has made huge gains

Discovery of the Century at LHC? ILC will help dig down and uncover deeper picture

International Linear Collider

International Linear Collider: Performance Specification (White Paper) –Initial maximum energy of 500 GeV, operable over the range GeV for physics running. –Equivalent (scaled by 500 GeV/  s) integrated luminosity for the first four years after commissioning of 500 fb -1. –Ability to perform energy scans with minimal changeover times. –Beam energy stability and precision of 0.1%. –Capability of 80% electron beam polarization over the range GeV. –Two interaction regions, at least one of which allows for a crossing angle enabling  collisions. –Ability to operate at 90 GeV for calibration running. –Machine upgradeable to approximately 1 TeV.

Key Points for Why We Want the ILC New physics is expected at the TeV scale Synergy with LHC Discoveries Discoveries lead to questions such as: –Standard model Higgs? Measure couplings, spin, parity –Is that supersymmetry? Measure spin and quantum nos. –Is that neutralino “dark matter” Measure mass to 1% –How many extra dimensions are there? LHC+ILC best Precision Higgs Factory Measurements are a window to new physics

Higgs at ILC Little Higgs Model Quadratic divergence of the Higgs boson mass can be cancelled by extra fermions and bosons about 1TeV. Higgs-less Model A new model based on 5 dim space-time. The unitarity of the WW scattering is saved by the Kaluza-Klein modes of the gauge bosons. etc.. Higgs Self Coupling Crucial information on Higgs potential Self coupling to 10%(Yamashita) 4 b-jets 80% efficiency 2 years running

ILC has Powerful Recoil Technique Peak in recoil mass corresponds to Higgs Sensitive to invisible Higgs decay In e+ e-  Z + anything (even invisible decay products) the recoil mass of system is determined by kinematics and conservation of energy.

Measuring the Higgs Spin and Parity Scan hZ production near threshold 20 fb -1 per point Can unambiguously show that J P =0 + Difficult to do at LHC Miller et al.

Powerful Test at ILC The absolute cross section of e+ e-  Z*  Zh involves vertex that gives Z its mass. Sum rule tests whether observed h 0 generates all mass of the Z boson. LHC measures ratios of couplings and cannot determine the ZZh coupling directly. If the production rate is smaller, then multiple h 0 bosons must be contributing to Z mass. H Z Z*Z* e-e- e+e+ l+l+ l-l- At ILC : (6% of Z decays)

Higgs Branching Ratios Measure Higgs decay branching ratios by measuring system that recoils against Z This level of precision only possible at ILC qualitatively different from LHC (Hinchliffe)

~ m f Perform accurate & Model Independent measurements of the Higgs Couplings Higgs Critical Test The strength of the Higgs couplings to fermions and bosons is given by the mass of the particle Important to detect cleanly all quarks f -f-f From Joanne Hewitt Look for deviation from straight line SUSY and Extra Dimension Models can behave differently Small uncertainties

Precision SUSY at ILC ILC has a central role to play in SUSY SUSY observables at ILC qualitatively beyond LHC (Peskin) Super particles could be heavy but lightest chargino should be seen at 500 GeV ILC (proposed initial energy). All charginos and neutralinos should be seen at a 1 TeV ILC Definitive determination of spin and quantum numbers Mass of lightest super symmetric particle to 1% (LHC 10%) Precision mass measurements of super particles Measure chargino and neutralino mixing (higgsino and gaugino) If neutralino is lightest super particle and R-parity conserved then it is stable and a dark matter candidate Only ILC provides accurate enough input for dark matter relic abundance calculations which seem to get in ball park of WMAP allowed range

New Gauge Bosons Measure Z΄ couplings given mass from LHC Indirect sensitivity beyond LHC even at 500 GeV Riemann

ITRP (Wise Cold People) (International Technology Recommendation Panel) “This recommendation is made with the understanding that we are recommending a technology, not a design.” August 20 th, 2004 Super conducting RF is accelerating technology choice (Global all aboard!)

ILC Design Needed Good Start

ICFA FALC Resource Board ILCSC GDE Directorate GDE Executive Committee Global R&D Program RDR Design Matrix GDE R & D Board GDE Change Control Board GDE Design Cost Board GDE RDR / R&D Organization GDE

Baseline  Reference Design Report Jan JulyDec 2006 Freeze Configuration Organize for RDR Bangalore Review Design/Cost Methodology Review Initial Design / Cost Review Final Design / Cost RDR Document Design and CostingPreliminary RDR Released FrascatiVancouverValencia

The ILC Baseline Machine not to scale ~31 km RTML ~1.6km 20mr 2mr BDS 5km ML ~10km (G = 31.5MV/m) x2 e+ 150 GeV (~1.2km) R = 955m E = 5 GeV

Baseline Electron Source Positron-style room- temperature accelerating section diagnostics section standard ILC SCRF modules sub-harmonic bunchers + solenoids laser E= MeV DC Guns incorporating photocathode illuminated by a Ti: Sapphire drive laser. Long electron microbunches (~2 ns) are bunched in a bunching section Accelerated in a room temperature linac to about 100 MeV and SRF linac to 5 GeV.

Baseline Positron Source Helical Undulator Based Positron Source with Keep Alive System –The undulator source will be placed at the 150 GeV point in main electron linac. This will allow constant charge operation across the foreseen centre-of-mass energy operating range. Primary e - source e - DR Target e - Dump Photon Beam Dump e + DR Auxiliary e - Source Photon Collimators Adiabatic Matching Device e + pre- accelerator ~5GeV 150 GeV100 GeV Helical Undulator In By-Pass Line Photon Target 250 GeV Positron Linac IP Beam Delivery System

Baseline ILC Cryomodule The baseline ILC Cryomodule will have 8 9-Cell cavities per cryomodule. The quadrupole will be at the center in the baseline design. Every 4 th cryomodule in the linac would include a quadrupole with a corrector and BPM package.

Main Linac: Baseline RF Unit

ILC Damping Ring: Baseline Design Positrons: Two rings of ~ 6 km circumference in a single tunnel. Two rings are needed to reduce e-cloud effects unless significant progress can be made with mitigation techniques. Preferred to 17 km due to: –Space-charge effects –Acceptance –Tunnel layout (commissioning time, stray fields) Electrons: one 6 km ring. Preferred to 3 km due to: –Larger gaps between mini-trains for clearing ions. –Injection and extraction kickers ‘low risk’

RF Power: Baseline Klystrons ThalesCPIToshiba Specification: 10MW MBK 1.5ms pulse 65% efficiency ILC DESY) has a very limited experience with these Klystrons. Production and operation of these Klystron are issues that needs to be addressed.

Baseline (supported, at the moment, by GDE exec) –two BDSs, 20/2mrad, 2 detectors, 2 longitudinally separated IR halls Alternative 1 –two BDSs, 20/2mrad, 2 detectors in single IR Z=0 Alternative 2 –single IR/BDS, collider hall long enough for two push-pull detectors Beam Delivery System (BDS)

Site power : 140 MW (500 GeV baseline) Sub-Systems 43MW Main Linacs 97MW Cryogenics: 21MW RF: 76MW 65% 78% 60% Beam 22.6MW Injectors Damping rings Auxiliaries BDS

ILC is a Truly Global Project Project initiated by three regions of world Design performed in all three regions of world R&D is all three regions Test Facilities in all three regions Accelerator Physicists Work Well Together Decision on site will be global, as was technology decision US will bid to Host (DOE working towards this goal)

Main ILC R&D Issue Produce high gradient cavities reliably

SRF Cavity Gradient Cavity type Qualified gradient Operational gradient Length*energy MV/m KmGeV initialTESLA upgradeLL * assuming 75% fill factor Total length of one 500 GeV linac  20km

Cavities for Module DESY

Vertical Test DESY, 9 cavities

ILC Main Linac Accelerator R&D Goals The ILC-Global Design Effort (GDE)’s priorities as being discussed by the S0, S1 and S2 Task Forces. Still being defined…present stage the goals being discussed are: –Develop cavity processing parameters for a reproducible cavity gradient of 35 MV/m; improve the yield of 9-cell cavities for gradient of 35 MV/m in vertical tests (S0). Carry out parallel/coupled R&D on cavity processing, fabrication and materials to identify paths to success. –Assemble and test one or more cryomodules with average gradient > 31.5 MV/m (S1). –Build and test one or more ILC rf units at ILC beam parameters, high gradient, and full pulse rep rate (S2.1) –To develop plans for an ILC Main Linac System Test consisting of several rf units (S2.2). To achieve the goals, R&D plan will also strengthen the technical capabilities and infrastructure of collaborating institutions.

Global Plan Emerging Back to Basics

Re- entrant Cornell KEK Low Loss Jlab KEK Tesla Shape Need Multi-cells Next New Shapes Breakthrough 50 MV/m in Single Cells ! Lower Surface Magnetic Field & Lower Losses

Fabricated at Cornell Higher Gradient in Single Cell: Eacc = MV/m KEK

ILC Cavity Material Grain size R&D The single cell and/or large grain Niobium shows considerable promise in achieving higher gradient. R&D activities are under way at KEK, Jlab and DESY using single cell cavities. It could eliminate the need to electro- polish Two 9-cell cavities are being fabricated. Ningxia Heraeus

US: ILC Cavity R&D In order to make timely progress on the ILC cavities gradient goal Fermilab has taken the approach that –Maximizes the utilization of existing U.S. SRF infrastructure –While developing Fermilab based expertise and infrastructure. AES ACCEL 60 Cavities (by FY07)

R&D Around the World Three Regions-only look at DESY, KEK, US

Japan ATF/ATF2

KEK: Main Linac SRF Unit R&D Goal: Achieve Higher Gradient >40 MV/m in a new Cavity Design Parallel Fermilab but emphasis on high gradient

The inter-cavity connection is done in class 10 cleanroom The assembly of a string of 8 cavities into a string. Class 100 clean room Facilities being setup at Fermilab as part of SMTF. DESY String Assembly

INFN/DESY Co-Axial Tuner Successfully operated with superstructures Piezo-tuner integration still pending Lorentz Force Detuning Micro-phonics

The module assembly is well defined and about 10 modules have been made of several designs ILC will need about 4000 modules. DESY Module Assembly

Cryomodules at DESY TTF European Activities Centered Around DESY Lab in Germany

Fermilab: A Possible Host of ILC A Truly International Laboratory will be necessary

ILC 1.3 GHz FNAL Industrial fabrication of cavities. BCP and vertical testing at Cornell (25 MV/m) EP and vertical testing at TJNL. ( 35 MV/m) Joint BCP/EP facility being developed ANL (late 06) High Power Horizontal test FNAL (ILCTA-MDB) Vertical test facility under FNAL ( IB1) Single/large Crystal cavity development with TJNL 4 cavities received from ACCEL 4 cavities on order at AES 4 cavities expected from KEK Bead pull RF FNAL Joint ANL/FNAL BCP/EP Facility

Vertical Test of ACCEL Cavity 60  m BCP (nominal) + 50  m at ACCEL Low Field: Q >5x10 10, E acc = 26 MV/m Q E acc (Mv/m)

Fermilab ILC Infrastructure RF Measurement and Tuning Cavity String Assembly Clean Room Class 10/100 Cryomodule MP9 Fermilab Fermilab Photo-injector Eddy Current Scanner LLRF

Horizontal and Vertical Test Stands Single Cavity Horizontal Test Stand Improved Design compared to DESY Bid Package is out Plan to install and commission at Meson in summer 06. Multiple Cavities Vertical Test Stand Fermilab had designed VTS for DESY We are in process of designing a new VTS to be installed at IB1. It is expected to be operational in CY06.

Cryomodule Design & Fabrication In FY05 Fermilab started on converting the DESY/INFN design of the ILC cryomodule (Type-III+). Fermilab is part of a group that is working towards a design of an ILC cryomodule. The Goal is to design an improved ILC cryomodule (Type-IV) and build one at Fermilab by FY08. High Power testing of the cavities and the fabrication of 1st US cryomodule with new design 2008.

Fermilab Phase 1: 1 RF Unit 1 st RF Unit Integrated by US Laboratories and Universities Photo-injector Phase B Diagnostics 40 MeV e- beam Dump SLAC Fermilab ILC LLRF, Control, Instrumentation, Feedback etc. ILC Institutions Components provided by US and International Collaborators Goal: Address S1 and S2 issues. 2 nd RF Unit Produced and Integrated by ILC laboratories, Universities and Industries

HPR and Assembly Alignment Cage Jlab: Electro-polish Development for ILC Jlab EP Cabinet This facility has been commissioned. 9-Cell TESLA Shape cavity result soon

ILC Industrialization The principle goal industrialization activities is: Establish industrial the capability and infrastructure to manufacture the components that must be mass produced SCRF Cavities: ~20,000 cavities required for 500 GeV of linac Reliably achieve > 35 MV/m and Q ~1x10 10 Cryomodule design that can be mass produced ~2000 required/500 GeV of linac RF systems ~ 600 klystrons ( 1.3 GHz, 10 MW, 1.5 ms, 5 Hz) ~ 600 modulators Waveguide, circulators, host of other RF and vacuum components… Large Cryogenic systems (~ 40 KW at 1.8 K) Detectors, instrumentation, etc… etc… Civil construction Industrial studies aimed at cost reduction in all three regions

Summary Precision measurements at the ILC necessary for us to understand phenomena at TeV Scale –Higgs + new physics (Little Higgs, SUSY, Extra Dimensions…… ILC is powerful instrument (polarization, initial energy known, energy scan Organization (Global Design Effort) established Timeline RDR 2006 (end) TDR 2009 R&D high priority worldwide Prepare to propose ILC