1. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 LHeC 1.Why 2.How 3. When 4. Summary John Dainton Cockcroft Institute and Univ Liverpool, Daresbury Science and Innovation Campus, GB and the University of Liverpool, GB with M Klein (Univ Liverpool) P Newman (Univ Birmingham), E Perez (CERN) F Willeke (DESY Hamburg and BNL) and more and more …… ! hep-ex/0603016, JINST 1 (2006) P10001, and DIS06 Proceedings

2. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 1.Why?

3. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Why: Leptons  Quarks ? how are leptons and quarks related ? put them together at the highest energy at finest detail ICHEP86 Berkeley

4. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 TeV eq Kinematic Reach space-like >TeV s eq >TeV 3×10 -7 - Q 2 ≤ 30,000 GeV 2 - s eq ≤ (300 GeV) 2 in ~ 0.7 am ● 2007: HERA - Q 2 ≤ 2×10 6 GeV 2 - s eq ≤ (2000 GeV) 2 in ~ 0.1 am ! ● ≥2016?: LHeC LHeC ee RL ?

5. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Lepton+quark @ TeV LHC LHeC SM (hadronic) + signal LqLq productionS ~ few × 0.1 fb (Λ=0.1) SM (electroweak) + signal Lq formation ~ 100 fb (Λ=0.1) ● leptoquark systems – new physics +SM Re + resonance

6. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Lepton+quark @ TeV ● leptoquark systems – new physics +SM 1 TeV

7. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 e, q e+ F=0 e- F=2 qq  g  Lq Lq production mechanism ? disentangle mass spectrum ? e q e q ** LHC Lq pairsLHeC Lq formation+decay fermion number e+ e- q or q ? _ _ _ _ Lepton+quark @ TeV spin parity and chirality defined formation (e LR )  precision BRs (NC CC) inclusive coherence unique PWA SM + signal + interference exp l sigjets + leptonsjet+(lepton)+p T (im)balance

8. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 e, q e+ F=0 e- F=2 gq  Lq l production mechanism ? disentangle mass spectrum ? e q e q ** LHC LqLHeC Lq formation+decay fermion number _ Lepton+quark @ TeV spin parity and chirality defined formation (e LR )  precision BRs (NC CC) inclusive coherence unique PWA SM + signal + interference exp l sigjet + leptonsjet+(lepton)+p T (im)balance

9. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Chadwick Cambridge nucleus nucleon quark NC+CC+gluon ● LHeC g+EW ? ● unique chiral probe @ 0.0001 fm ? ● protons+neutrons Manchester SLAC ● 70  7000 GeV e ± p cm energy 1400 GeV SM + new Lq physics @ ~ 0.0001 fm ? SM + new Lq physics @ ~ 0.0001 fm ? Lepton+quark @ TeV Structure of Matter @ TeV SM + q structure @ ~ 0.0001 fm ? SM + q structure @ ~ 0.0001 fm ?  Z W ee RL ? Q 2 y x ee ee QCD

10. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ● precision  discovery probe new chromodynamic physics – beyond SM ? ● short distance structure of SM+ - 2006  @ 10 -9 - 2006 G F @ 10 -5 - 2006 G @ 0.1% - 2006  S @ 1-2% - LHeC + detector   S few/mil precision  QCD at highest energy Unification ?

11. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ● LHeC Chadwick Cambridge nucleus nucleon quark NC+CC+gluon g+EW ● protons+neutrons Manchester SLAC ? ● unique chiral probe @ 0.0001 fm ? ● 70  7000 GeV e ± p cm energy 1400 GeV SM + new Lq physics @ ~ 0.0001 fm ? SM + new Lq physics @ ~ 0.0001 fm ? Lepton+quark @ TeV Heavy Flavour in Hadron Chromodynamics SM @ ~ 0.0001 fm heavy flavour SM @ ~ 0.0001 fm heavy flavour  Z W ee RL ? Q 2 y ee ee x NC  + Z b

12. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 what we have to find ● Higgs at LHC what we know now Heavy Flavour in Hadron Chromodynamics …… what we could know …… underpins discovery X=?

13. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Why: Dense Colour ? the origin of mass in the Universe probe hadronic matter at highest parton density at lowest Bjørken-x "Most of the mass of ordinary matter is concentrated in protons and neutrons. It arises from …[a]… profound, and beautiful, source. Numerical simulation of QCD shows that if we built protons and neutrons in an imaginary world with no Higgs mechanism - purely out of quarks and gluons with zero mass - their masses would not be very different from what they actually are. Their mass arises from pure energy, associated with the dynamics of confinement in QCD, according to the relation m=E/c 2. This profound account of the origin of mass is a crown jewel in our Theory of Matter.’’ Frank Wilcek CERN October 11, 2000

14. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 - x Bj ≥ 5×10 -5 -x Bj ≥ 5×10 -7 TeV eq Kinematic Reach space-like >TeV s eq >TeV - Q 2 ≥ 1 GeV 2 ● 2007: HERA LHeC x Q 2 y ee ee - Q 2 ≥ 1 GeV 2 ● ≥2016?: LHeC Growing Field Energy Density 3×10 -7

15. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Growing Field Energy Density ● ≥2016?: LHeC -x Bj ≥ 5×10 -7 Gluon recombination x Q 2 y ee ee low x large nuclei - Q 2 ≥ 1 GeV 2 Q 2  size of gluons x Bj  phase space for gluons

16. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Gluon recombination @ LHeC ● ep saturation Q 2 ≤ 5 GeV 2 eA saturation Q 2 ≤ 20 GeV 2

17. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 DGLAP Dense Chromodynamics ● low-x rise of F 2 - LHeC: precision eg x > 3×10 -3 @ Q 2 =10000 GeV 2 x =βx IP ● low x P physics QCD  reggeon calculus ? I

18. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 2.How?

19. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Proton beam ● ”standard” LHC protons protons antiprotons protons N p ε pN … with electrons? protons electrons?

20. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ep Luminosity ● few 10s GeV electrons (LEP = 70 GeV!) ● RF power = 50 MW = 0.86 LEP = 28% CERN site ● RF power = synchrotron radiation  I e = 74 mA luminosity 74×10 -3 ×1.67×10 11 ×7000/.938 4π×1.6×10 -19 ×3.75×10 -6 ×  = L = 1.15×10 33 /  (m 2 ) cm -2 s -1 L ~ 10 33 cm -2 s -1 for reasonable p-beam β ~ 1 m “perfect” bunch x-ing

21. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ● L LHeC e ± p eA @ 0.00014 fm ● L LHeC e ± p eA @ 0.00014 fm e ± p Luminosity ● astounding ! ● ×10 2 L NMC μp @ 0.01 fm ● ×10 2 L NMC μp @ 0.01 fm ● L eRHIC e pol p pol eA @ 0.007 fm ● L eRHIC e pol p pol eA @ 0.007 fm indisputably a next step … is it feasible ? ● ×10 2 L HERA e pol p @ 0.001 fm ● ×10 2 L HERA e pol p @ 0.001 fm

22. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Lepton Ring ● in LEP tunnel … so like LEP - FODO in eight arcs β-tron phase advance φ H =108 o φ V =90 o - bending radius 3133.3 m - (δE/E beam ) rms = 1.1×10 -3 - SR 26 W/cm (E c =254 KeV) - scRF @ 1GHz resonators @ 12 MV/m 100 m structure = 670 cells  sync. phase 31 o  bucket takes 10× (δE/E beam ) rms - unlikely e-beam instability single bunch current modest impedance << LEP LEP=9 W/cm HERA=13.5 W/cm scRF proven @ > 6 MV/m 1 2 3 4 5 6 78

23. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ep Collisions ● after B physics @ LHC ep alongside pp data-taking @ LHC p e civil engineering tunnel 2×250m×2m Ø @IP civil engineering tunnel 2×250m×2m Ø @IP LHeC

24. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Interaction Region ● highest lumi - low β e close sc quads - low X-ing angle “hard” bend SR fan  sc p-beam « HERA - “crab” RF cavity p-bunch rotation 3.5 mrad 0.5 mrad V-displaced top elevation 11.4 kW 3.4 kW3.2 kW ● 1 o beam access = low-lumi/low-x option (cf HERA) “crabbed” (rotated) p-bunch

25. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ● beam-beam - “hour-glass” - dynamic β: < HERA - long range beam-beam (parasitic interactions): marginal Operational Luminosity operational luminosity

26. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 LHeC ● tunnel exists (LEP, LHC) ● injection once existed (LEP) ? ● operating p-beam (from 2008) ● operating A-beam (from 2008) ● ep eA operating alongside pp pA AA ● the TeV ep collider ! ● ”minimal” mods to LHC ! ● LHC upgrade ● cost ?

27. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 IR and Experiment ● IR ±many m ● IR ≥9.4 o around beam

28. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 electron Asymmetric Collider quark p 7 TeVe 70 GeV ● asymmetric beam momenta: LHeC ~ TeV ● ”forward” hemisphere detection to multiTeV topological challenge precision challenge quads ?

29. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 3.When?

30. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Timeline ● 2007: form working groups + steering committee initial meeting of conveners + committee SAC overview ● 2008: workshop I ● 2009: workshop II LHeC Design Study [LHCC] ● 2011: TDR - construction 8 years - installation e-ring above LHC ~1 year - LHeC part of LHC upgrade - be aware of CLIC progress

31. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Working Group Structure 1.Accelerator (injector, ring) 2.Interaction region 3.Detector 4.The new physics 5.High precision QCD 6.Low x physics 7.eA tbc (SAC)

32. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 LHeC Scientific Advisory Committee Joel Feltesse (Saclay/DESY) Guido Altarelli (Roma) Rolf Heuer (DESY) Aharon Levy (Tel Aviv) Lev Lipatov (Petersburg) Allen Caldwell (MPI Muenchen) Young-Kee Kim (Fermilab) Jos Engelen (CERN) Roland Horisberger (PSI) Stephen Myers (CERN) Stan Brodsky (SLAC) Roland Garoby (CERN) Ferdinand Willeke (DESY/BNL) Swapan Chattopadhyay (Cockcroft Institute) Peter Bond (BNL) Richard Milner (MIT) John Dainton (University of Liverpool)

33. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 4.Summary

34. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Now ● LHeC 70 e  7000 p GeV - can be built - has startlingly good luminosity ≥ 10 33 cm -2 s -1 grows with LHC pp luminosity - adds substantially, uniquely, and with synergy to LHC TeV discovery physics - probes chromodynamics @ new density frontier in uniquely comprehensive manner with unchallengable precision synergetically with LHC pp pA AA

35. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 LHeC and ILC ● energy for eq discovery extreme chromodynamics ● precision for eq discovery eq understanding extreme chromodynamics ●luminosity for eq discovery LHeC and LHC Lepton + quark @ TeV

36. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 In case you were wondering … ? Sir John Cockcroft … doing accelerator physics ca 1950 … … with 1950 DAQ – pencil and paper! … with 1950 graphics – ammeter! voltmeter!

37. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Lepton-Parton and Parton-Parton ?  Z W ee RL ? ? g q ? ? ep  eX pp  (jet+jet)X probe-parton jet LHeC energy scale: 70  7000 GeV pp energy scale: 7000  7000 GeV x probe/p = 0.01 probe+p at LHeC scale

38. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 LHC probe parton - xq = xU +xD +xU +xD g :q ~ 2:1 ● probe-parton @ x  0.01 ● probe-parton @ x » 0.01 g :q  0 “mixed” LHC probe @ LHeC energy q LHC probe @ LHC top energy

39. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Lepton-Parton and Parton-Parton  Z W ee RL ? ? g q ? ? ep  eX pp  (jet+jet)X probe-parton jet precise probe e precise kinematics smaller kinematic reach but - eq  eq “formation”  TeV - precision at lower x Bj ≥10 -7 probe g and q kinematics ? larger kinematic reach x larger  probe q q/gq/g  eqeq pair production

40. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Dense Chromodynamics ● relentless low-x rise of F 2 - saturation? partons must someday recombine - LHeC: precision eg x > 2×10 -4 @ Q 2 =1000 GeV 2 F2F2 Q 2 =1000 GeV 2 x g/p

41. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 ≥ 20 g/nucleon/ln x @LHeC … in heavy ion ? ≥ 20 g/nucleon/ln x @LHeC … in heavy ion ? Dense Chromodynamics ● relentless low-x rise of F 2 - LHeC: precision for x > 2×10 -4 @ Q 2 =1000 GeV 2 F2F2 20 10 Q 2 =1000 GeV 2 10 -3 ≤8 gluons/ln x @ HERA x g/p ≥2×10 -4 @ LHeC x g/p precision pdfs - BFKL? CCFM ? high density - recombination - saturation ? - instantons ? - other “ons” ? - condensates ? - other “ates” ?

42. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 Barber

43. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 What’s been achieved ● Sokolov-Ternov + spin-rotators @ HERA

44. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007 What’s been achieved ● Sokolov-Ternov @ LEP 70 GeV

45. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007

46. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS07 Munich April 2007