2. The Linear Collider: a UK perspective Introduction to the machine Detectors UIK activities Timescales Some key Physics (time ?) Summary Grahame A. Blair Edinburgh, 8 th February 2006

3. www.linearcollider.org

4. Superconducting Niobium Cavities

5. Y. Kokoya, GDE Frascati 2005

6. Generic Linear Collider Damping Rings Particle Sources Main Linac (RF) Beam Delivery System DR Circumf. Baseline: 6km

7. Damping Process

8. Y. Kokoya, GDE Frascati 2005

9. A Possible Layout Approximately follow earth’s curvature Upgrade path to ~1 TeV

10. LC for Physics Purposes: e + e - collisions with √s tuneable 0.5 – O(1) TeV e - e - mode. Polarisation: e - 80% (L/R); e + 60% (?). Possibility to run at √s ~ 90 – 160 GeV (“GigaZ”) Luminosity 3-6.10 34 cm -2 s -1  specific analyses can assume up to about 1 ab -1 Also possible/important; Compton scattering to produce  or e 

11. Bunch Interactions e+e+ e-e- Increase in luminosity (×~2) Beamstrahlung  Lumi. Spectrum Schulte

12. Luminosity Spectrum sharp peak approx same as ISR (tuned) – few % in tail for 0.5-1 TeV machines TESLA TDR

13. Precision Measurement of the Top Mass Precision measurement of fundamental particle properties The top quark is the heaviest: most sensitive to new physics E tot (GeV) Cross section (pb) Statistical Precision ~0.05 GeV  0.02% M top =175 GeV 100 fb -1 per point Martinez et al.

14. Initial State e-Re-R e+Le+L W-production suppressed s-wave production of charginos ~  sharp threshold Specific polarisations for specific couplings (eg SUSY) e-Re-R e-Re-R s-wave production of selectrons ~  sharp threshold RR RR Direct production of higgs http://www.ippp.dur.ac.uk/~gudrid/power/

15. Worldwide LC Studies http://blueox.uoregon.edu/~lc/wwstudy/ http://acfahep.kek.jp/ http://blueox.uoregon.edu/~lc/alcpg/

16. Worldwide studies (2) http://www.desy.de/conferences/ecfa-lc-study.html http://clicphysics.web.cern.ch/CLICphysics/

17. The Detectors http://physics.uoregon.edu/~ lc/wwstudy/concepts/

18. Adapted from Y. Kokoya, GDE Frascati 2005 Number of IPs 2 IPs + 2 detectors is the baseline. The cost of 2nd IP (beamline + exp.hall) corresponds to the energy 14-19% of 500GeV (change of tunnel cost not included). Caveats: Total cost estimation from 3 regions agree well but the cost of individual components scatter in wide ranges. This means 405-430 GeV LC with 2IP is comparable in cost with 500GeV LC with 1 IP It is possible that 1 IP will become the baseline – The physics community needs to make its case clear

19. Design philosophy Aim for SiW calorimeter with best possible resolution Keep radius small to make this affordable Compensate by high B- field (5 T) and very precise tracking (Si) Fast timing of Silicon to suppress background SID

20. Design philosophy Fine resolution calorimeter for particle flow Gaseous tracking for High tracking efficiency and redundancy Large enough radius and high enough B-field (B=4 T) to get required momentum resolution LDC

21. Design philosophy Large radius for particle-flow optimisation Gaseous tracking for High tracking efficiency and redundancy Fine grained scintillator-tungsten calorimeter Moderate B-field (3 T) GLD

23. Energy Flow in Jets Some processes where WW and ZZ need to be separated without beam constraints. Requires ΔE/E~30%/  E

26. S. Worm, LCUK meeting, Oct 05

28. Particle/Machine Physics The LC will be a very challenging machine Particle physicists are taking part in machine studies Beam diagnostics and control Background estimates Design studies The particle physics programme now goes beyond “what comes out of the IP”.

29. UK funding for accelerator science for particle physics 2004 - 2007 UK funding agency, PPARC, secured from Govt. £11M for ‘accelerator science’ for particle physics, spend period April 04 – March 07 Called for bids from universities and national labs; large consortia were explicitly encouraged LC-Beam Delivery £9.1M + 1.5M CCLRC UKNF £1.9M 2 university-based accelerator institutes: John Adams: Oxford/RHUL Cockroft: Liverpool, Manchester, Lancaster, NW dev. agency. Funding period ends in 2007; new bid will be finalised in July 2006.

30. LC-ABD Collaboration Bristol Birmingham Cambridge Dundee Durham Lancaster Liverpool Manchester Oxford QMUL RHUL University College, London Daresbury and Rutherford-Appleton Labs; 41 post-doctoral physicists (faculty, staff, research associates) + technical staff + graduate students

31. UK Interests: Beam Delivery System

32. Beam Delivery System ~3km Full simulations Backgrounds Optimisation Precision Diagnostics Energy Polarisation Luminosity

33.  Final Focus and extraction line optimized simultaneously  Quadrupoles and sextupoles in the FD optimized to  cancel FF chromaticity  focus the extracted beam SLAC-BNL-UK-France Task Group QF1 pocket coil quad : C. Spencer O.Napoly, 1997 2 mrad Optics Design D. Angal-Kalinin

34. BDSIM Beamlines are built of modular accelerator components Full simulation of em showers All secondaries tracked Screenshot of an IR Design in BDSIM

35. BDS: Muon Trajectories BDS Concrete tunnel 2m radius View from top

36. Multi-Seed Luminosity Studies with the ILC Simulation Model 350 GeV CME 500 GeV CME ANG + IP Fast Feedback LUMI Feedback Optimisation (Position + Angle) G. White

37. 37 FONT3 installation on ATF beamline BPM processor board Amplifier/FB board FEATHER kicker ATF beamline installation June 05 P. Burrows

38. Bunch-Bunch Interaction Simulations Before interactionDuring interactionAfter interaction TESLA parameters low Q parameters P INIT =1.0

39. Laser-wire: Principle

40. Laserwire - PETRA + UCL 11.2.05 System recently upgraded

41. ATF-LW Vacuum Chamber Built at Oxford DO + Workshop Vacuum Tested At DL

42. Superconducting Helical Undulator Superconducting bifilar helix First (20 period) prototype constructed (RAL) Design field0.8 T Period14 mm Magnet bore4 mm Winding bore6 mm Winding section 4  4 mm 2 Overall current density1000 A/mm 2 Peak field (not on-axis)1.8 T Cut-away showing winding geometry Parameters

43. Wakefields θ Change in beamline aperture Wake-fields from the head of the bunch can disturb the tail Wake-fields from earlier bunches can disturb later ones (such effects can also be useful – eg. Smith-Purcell radiation)

44. Wakefield box ESA  z ~ 300  m – ILC nominal  y ~ 100mm (Frank/Deepa design) Magnet mover, y range =  mm, precision = 1  m 1500mm N. Watson

45. SlotSide viewBeam view 1  =324mrad r=2.0mm 2  324mrad r=1.4mm 3  324mrad r=1.4mm 4  =  /2rad r=4.0mm h=38 mm 38 mm L=1000 mm 7mm  r=1/2 gap As per last set in Sector 2, commissioning Extend last set, smaller r, resistive WF in Cu cf. same r, tapered

46. Overview of LC Projects Essentially independent of Linac-technology

47. The GDE Plan and Schedule 2005 2006 2007 2008 2009 2010 Global Design EffortProject globally coordinated Baseline configuration Reference Design ILC R&D Program Technical Design FALC Siting International Mgmt expression of interest sample sites regionial coord ICFA / ILCSC Funding Hosting

48. Machine Summary The ILC is now being defined. The Baseline is under “Configuration Control” Global Design Effort is in place, with a very active programme aiming at a Reference Design Report at end of 2006. UK is involved in two detector projects and an exciting range of accelerator R&D. The next round of accelerator-related bids are due for this summer.  a great time to get involved.

50. ILC Physics:

51. Higgs Production For M h ~120 GeV, 500 fb -1, √s=350 GeV  80,000 Higgs TESLA TDR

52. Higgs Spin Threshold excitation curve  determine spin 20 fb -1 per point TESLA TDR

53. Higgs Mass m h =120 GeV m h =150 GeV 500 fb -1 at √s=350 GeV TESLA TDR

54. Higgs Recoil Mass h Z ++ -- E tot = 2 E beam P tot = 0 500 fb -1, √s=350 GeV TESLA TDR

55. Higgs Mass Precision M h (GeV)Channel  M h (MeV) 120llqq70 120qqbb50 120combined40 150ll recoil90 150qq WW130 150combined70 180ll recoil100 180qq WW150 180combined80 500 fb -1, √s=350 GeV

56. Higgs Branching Ratios h→h→  BR/BR bb0.024 cc0.083 gg0.055 ττ0.050 For m h =120 GeV Battaglia

57. Higgs Potential  λ/λ=0.22 (statistical) for m h =120 GeV Requires 1000 fb -1 Muehleittner et al.

58. Supersymmetry

59. Need to discover the SUSY partners Every SM has a superpartner Spins of SM/SUSY partner differ by ½ Identical gauge quantum numbers Identical couplings To prove existence of SUSY: Needs accurate measurements of Mass spectra, cross-sections, BRs, Angular distributions, polarisation

60. SUSY Reference Points Work with Sugra SPS1a: M 1/2 =250 GeV M 0 =100 GeV A0=-100 GeV sign(  )=+ tan  =10 Higgs gauginos sleptons squarks √s=500 GeV √s=1TeV

61. Mass Measurements Threshold scans chargino ~  slepton ~  3 100 fb -1 Martyn et al.

62. Endpoint Measurements √s=400 GeV L=200 fb -1  Both sparticle masses Martyn

63. e - e - running Freitas, Miller, Zerwas Feng, Peskin Including width effects  m~50 MeV for 4 fb -1

64. Luminosity Budget Several running modes required. Input will already exist from LHC Grannis et al.

65. Model-Independent Extrapolation Renormalisation Group Eqns Measure complete spectrum Extract soft SUSY parameters at EW scale Input measured masses, couplings into RGEs Extrapolate model independently to high scales

66. Extrapolation: gaugino M i -1 GeV Porod, Zerwas, GB

67. Mi2Mi2 Q (GeV) Extrapolations mass terms mSUGRA structure reconstructed Fine structure?

68. GigaZ The LC can also provide high luminosity running at the Z-pole and at W-threshold Approximately 100 fb -1 per year Needs specific linac bypass design TESLA TDR

69. Concrete example - point B’ of “updated benchmark” points: mSUGRA w/ tan  = 10, sgn(  )=+1, m 0 =57, m 1/2 =250, A 0 =0 Trodden, Birkedal LCWS04 (Adapted) WMAP LC LHC Cosmology links

70. Physics Summary The linear collider will provide high precision measurements at high energy: Masses, chiral couplings, branching ratios… Together with LHC data, LC allows model- independent extrapolations to very high energy scales. Exciting overlap with LHC analyses complementary searches, constraints in cascades… see G.W talk Links to cosmology Long term programme from O(1) TeV, GigaZ, , multi TeV. An exciting time ahead!