1. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Large Hadron electron Collider LHeC … 1.Introduction 2.LHeC: “energy, precision and luminosity” 3. The Physics Horizon 4. Experiment 5. Onwards ? John Dainton * Cockcroft Institute, Daresbury Science and Innovation Centre, GB http://www.lancs.ac.uk/cockcroft-institute/ … indisputably the next step Deep-Inelastic Lepton Scattering at the LHC * with M Klein (DESY Zeuthen) P Newman (Univ Birmingham), E Perez (CE Saclay) F Willeke (DESY Hamburg) hep-ex/0603016 DESY 06-006 Cockcroft-06-05

2. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 1.Introduction

3. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 2007: a vintage year for Physics ● July 2007: final HERA data sample e ± p  chiral probe @ 0.001 fm ● July 2007: first collisions @ LHC pp @ 14000 GeV @ 10 33 cm -2 s -1 ● July 2007: hitherto unique p and A beam 7 TeV per nucleon, high intensity new opportunities ? LR 20??: 70 GeV e ± in LHC tunnel e ± p  chiral probe @ 0.00014 fm LR ?

4. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Kinematic Reach ● 70  7000 GeV e ± p cm energy 1400 GeV  Z W ee RL quark structure @ ≥ 0.0001 fm quark structure @ ≥ 0.0001 fm space-like >TeV ? ? eq >TeV 3×10 -7

5. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Structure of Matter    d structure q = 2  / electron  point-like “source”  Z 0 W  nucleus nucleon quark NC+CC+gluon ● LHeC gluons EW ? ● unique chiral probe @ 0.0001 fm ? ● precision

6. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton SM -0.0001 -0.0003 -0.001 -0.003 -0.01 -0.03 -0.1 e+e-.e+e-. Progress … ? (fm) 1960 1970 1980 1990 2000 2010 ….?. ep p SLAC+CERN quarks in proton NC P ep QPM HERA QCD+EW EW QCD.. LQ l* q* SUSY? QCD+EW unification HF+EW ep eA QCD spin gluon leptons + quarks hadronic mass in Universe Higgs mass CKM ? ? ?. p  p  A beyond? CERN+FNAL HERA ep eA LHeC ? ep eA

7. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 2. LHeC: “energy, 2. LHeC: “energy, precision and luminosity” 2. LHeC: “energy, precision and luminosity”

8. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Proton beam ● ”standard” LHC protons protons antiprotons protons N p ε pN … with electrons? protons electrons?

9. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 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

10. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton ● L LHeC e ± p @ 0.00014 fm ● L LHeC e ± p @ 0.00014 fm e ± p Luminosity ● astounding ! ● ×10 2 L NMC @ 0.01 fm ● ×10 2 L NMC @ 0.01 fm ● L eRHIC @ 0.007 fm ● L eRHIC @ 0.007 fm indisputably the next step … is it feasible ? ● ×10 2 L HERA @ 0.001 fm ● ×10 2 L HERA @ 0.001 fm

11. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Feasible Luminosity ? ● bunch matching β e ε e = β p ε p = β p γ p ● electron β e constrained by depth of focus for p-bunches σ p ~ 7 cm ● electron emittance ε e constrained by - dynamic aperture - geometric aperture - beam-beam tune shifts feasible match with tolerable “hour-glass” loss σpσp

12. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton LHeC Specification

13. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 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 3005.3 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

14. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Lepton Ring LHeC

15. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton ep Collisions ● after B physics @ LHC during pp pA AA data-taking @ LHC p e civil engineering tunnel 2×250m×2m Ø @IP civil engineering tunnel 2×250m×2m Ø @IP LHeC

16. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 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

17. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Interaction Region ● high luminosity operation

18. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton ● beam-beam - “hour-glass” - dynamic β: < HERA - long range beam-beam (parasitic interactions): marginal Operational Luminosity operational luminosity !

19. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton IR and Experiment ● IR ±many m ● IR ≥9.4 o around beam

20. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton LHeC ● tunnel exists (LEP, LHC) ● injection once existed (LEP) ● operating p-beam (from 2007) ● operating A-beam (from 2007) ● ep operating alongside pp pA AA ● LHC upgrade ● cost ?

21. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 3.The Physics Horizon

22. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton New Kinematic Reach in Lepton-Hadron space-like >TeV eq >TeV 3×10 -7 ● Q 2 LHEC  10 2 Q 2 HERA ● x LHEC  10 -2 x HERA ● s LHEC  20s HERA eq ● extrapolation … …or interpolation ?

23. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Lepton-Parton and Parton-Parton ● s LHC  10 2× s LHeC 70 GeV ● for target parton x probe/proton = = 0.01 @ LHC s LHeC s LHC ● LHC probe - confused LHC>LHeC - complementary for LHC~LHeC gluon @ low-x

24. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Energy Frontier LQLQ e q … e q  Z Z ee q e 2 + LQLQ + q e ● leptoquarks 100 fb -1 10 fb -1 (1 year @ LHeC)

25. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Energy Frontier LQLQ e q … e q  Z Z ee q e 2 + LQLQ + q e ● leptoquarks - formation and decay -e ± q NC,CC - fermion number - branching ratios - spin-parity - chirality ? - flavourcoupling ● if LQ spectroscopy discovered precision tools to understand it

26. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Dense Chromodynamics ● relentless low-x rise of F 2 for x ≥ 10 -4 - saturation? partons must someday recombine - LHeC: precision for x > 3×10 -7 : extreme nuclei ? (∂F 2 /∂ lnx) Q 2

27. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Precision Chromodynamics ● short distance structure of QCD - 2006  @ 10 -9 - 2006 G F @ 10 -5 - 2006 G @ 0.1% - 2006  S @ 1-2% - LHeC  precision  S few/mil ● discovery + precision probe new chromodynamic physics ?

28. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Comprehensive Physics Horizon ● energy for eq discovery extreme chromodynamics ● precision for eq discovery eq understanding extreme chromodynamics ●luminosity for eq discovery LHeC and LHC LHeC and ILC LHeC and LHC

29. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 4. Experiment

30. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Acceptance and Measurement e ! ● 70  7000 GeV ● high lumi quads (±10 o bp)  Q 2 > 100 GeV 2 x > 3×10 -5 ● few GeV ≤ E h,e ≤ few TeV ● low lumi for low x (no quads)  1 < Q 2 < 100 GeV 2 x < 3×10 -5  “forward” hadrons: “forward rapgap” instrumentation  precision e/had-measurement 170 < θ e < 179 o 170 < θ h < 179 o jet e

31. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Rate ● 100/10 fb -1 = 100/LHeC y -1 @ Q 2 = 1 TeV 2

32. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 8. Onwards ?

33. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton 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 energy physics - probes chromodynamics @ new density frontier in uniquely comprehensive manner with unchallengable precision synergetically with LHC pp pA AA

34. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Now ● CERN: Engelen “work it out!” Fall 2005 ● hep-ex/0603016  CERN Council (CC) Strategy group - emphasised by speakers - encouraging individual response ● hep-ex/0603016 noted in the US  DoE strategy: meeting now on lepton-hadron ● strong interest in LHeC @ DIS2006 … to be carried to CERN Strategy group by its members @ DIS2006 - implies global support - confirms importance of breadth in future HEP CC Strategy Group  “interesting to work it out” ? ? Jan 2006 April 2006 May 2006

35. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Next ● begin preparation of detailed evaluation - establish global working group (CERN pivotal) 1. machine e ± injection e ± ring LHC impact and modifications 2. experiment 3. physics ● look for any remaining “showstoppers” ● prepare CERN “white book” ● LoI to LHCC ● cost 2009 ? other LHC upgrades ?

36. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton Coordinating Group ● organisation ? ● coordinator(s) ? ● first meeting where ? ● first meeting when ? ● first meeting to organise work + schedule

37. THE COCKCROFT INSTITUTE of ACCELERATOR SCIENCE and TECHNOLOGY DIS06 Tsukuba April 23 rd 2006 John Dainton In case you were wondering … ? Sir John Cockcroft … doing accelerator physics ca 1950 … … with 1950 DAQ – pencil and paper! … with 1950 graphics – ammeter! voltmeter!