Max Klein IoP meeting on the LHC upgrade, Liverpool, 27/6/2007

1. Lepton Nucleon Scattering at TeV cms Energies- the Large Hadron Electron Collider Project - LHeC - New Physics High Precision QCD New Parton Dynamics Partons in Nuclei The LHeC Project Max Klein IoP meeting on the LHC upgrade, Liverpool, 27/6/2007

2. Kinematic coverage of lepton proton scattering experiments

3. The Role of Deep Inelastic Scattering Resolution of Nucleon Structure ep facilities are the highest resolution microscopes using the virtual boson to resolve nucleon’s structure. The LHeC will explore dimensions around and below 10-19 m.

4. DIS determines the partonic dynamics and distributions with the best possible accuracy. Precision measurements of the quark and gluon momentum distributions in the proton will be crucial to understand physics beyond the standard model. At the LHeC fundamental measurements on pdf’s are possible: the gluon distribution, ALL quark distributions, e.g. b, d/u, s-sbar. also generalised, unintegrated, diffractive and nuclear parton densities - for the first time, in a new range + precise! The Role of Deep Inelastic Scattering

5. Formation of eq Resonances The Role of Deep Inelastic Scattering ep facilities lead to the possible formation of eq resonances at masses as high as M2 = sx . With high energy (s), high luminosity (large x) and variation of lepton beam charge and polarisation eq resonance spectroscopy can be studied, should new states exist (LQ, RPV SUSY)

6. LHC Q2 =M2 x=(M/√s) ey heavy masses: large Bjorken x lower masses & forward physics: low Bjorken x DIS and Drell Yan Kinematics

7. Parton luminosity to 1-2% requires partons to be known to 1-2% [low x, extrapolation resummation, HQ,..] Partons and the LHC Gluon and beauty and u/d distributions crucial for observations of new physics [cf high Et jet excess at Tevatron]

8. The strong coupling constant is the worst measured coupling of all Unification at GUT scale? A new level of precision and kinematic range Design detector [range, calibration] to measure s to per mil accuracy (thy NkLO) Full simulation of NC, CC including systematics and NLO fit

9. High luminosity to reach high Q2 and large x 1033 - 1034 1-5 1031 Largest possible acceptance 1-179o 7-177o High resolution tracking 0.1 mrad 0.2-1 mrad Precision electromagnetic calorimetry 0.1% 0.2-0.5% Precision hadronic calorimetry 0.5% 1% High precision luminosity measurement 0.5% 1% Detector requirements [under further study] The new collider has to be 100 times more luminous than HERA The new detector has to be at least 2 times better than the good old H1 In ep have redundant determination of kinematics from e and X Need low x and high Q2 detectors (fwd, central) LHeC HERA

10. Pioneering measurements of charm and beauty density. Theoretical treatment of crucial importance for LHC: CTEQ6 7% effect on W,Z from heavy quark treatment. Predictions very much based on extrapolations and on pQCD. No access to strange quarks. Heavy Quarks - HERA Ws -> c too small luminosity too small Q2

11. High precision measurements of beauty and charm from impact parameter tagging, also decays with modern Si trackers, beam spot 15 * 35 m2 . Profit from enhanced relative cross section (b/u+d ..) . Beauty crucial for LHC. Strange and anti-strange quark density From charm tagging in charged currents. Both charges will resolve s-sbar puzzle (NuTeV anomaly, npQCD). b Heavy Quarks - LHeC s c

12. HERA I valence quarks - xF3Z Valence quarks at low x or/and unexpected sea asymmetries from yZ interference Also from W+ W- at LHC

13. Partons at High x - High Masses Possibly crucial for discovery and interpretation of new states.

14. Extra dimensions: deviations in dijet mass spectra at high masses New Physics E.Perez, DIS07

15. Appear in many extensions of the SM Scalar or vector colour triplet bosons carry L and B, fractional charge Symmetry between q and l sector Cancellation of QED triangular anomaly New Physics - Leptoquarks Could be discovered via pair production at LHC up to masses of 1-1.5 TeV Charge, angular distribution, polarisation determine quantum numbers in ep

16. New Physics - Leptoquarks 10 fb-1 100 fb-1 Charge asymmetry much cleaner in ep than in pp. Similar for simultaneous determination of coupling and quark flavour

17. Is the rise limited, do densities saturate? Evolution dynamics (DGLAP, BFKL..) Final state, diffraction Huge fields of research on their own and in relation to the LHC What is the origin and range of the high density phase? instantons?.. LHeC: basis to understand pp,pA,AA. Neutrino and gamma astrophysics Low x Physics

18. High density amplification? Striking effects predicted: bj -> black disc limit F2Q2ln(1/x) ~50% diffraction colour opacity, change of J/(A) … High density Unitarity Understanding the possible observation of QGP in AA with eA

19. Available data on F2 in nuclei Limited information on quarks and nearly none on gluons The LHeC extends the eA kinematic range by 4 orders of magnitude K.Eskola (ed), hep-ph/0308248; S. Kumano DIS06; D.Florian and R. Sassot, hep-ph/0311227; FGS, Phys Rev.D71(05)054001; LMcLerran,Glasma..

20. Determination of nuclear PDF’s S. Kumano DIS06 In eA at the collider, test Gribovs relation between shadowing and diffraction, control nuclear effects at low Bjorken x to high accuracy

21. d/u at low x from deuterons Note all QCD fits assume u=d at low x No constraint from HERA [W asymmetry]

22. High Luminosity Npgp / eNp=3.2·1020m-1 Standard LHC p beam Power < 50MW Scaling from HERA Crab crossing 9kW SR power in IR Syn.rad. fan confined around ATLAS+CMS ep & pp operation cf. F.Willeke 14/6/07 accelerator seminar at CERN - so far feasible

23. ∑L e+ 294 591 297 e- 184 391 207 0.7fb-1 in 93-07 Bjoern Wiik, Gus Voss, Volker Soergel

24. Large Hadron electron Collider Design

25. Organisation: steering group 07: working groups 09: CDR 11: TDR for consideration when LHC has revealed sth LHeC Project in June 07 Scientific Advisory Committee Accelerator Experts C.Chattopadhyay, R.Garoby, S.Myers, F.Willeke Directors J.Engelen (CERN), R.Heuer (DESY), YK.Kim (Fermilab), P.Bond (BNL) Theorists G.Altarelli, S.Brodsky, J.Ellis, L.Lipatov,F.Wilczek Experimentalists A.Caldwell, J.Dainton, J.Feltesse, R.Horisberger, R.Milner, A.Levy Few invitations still outstanding

26. Remarks Carlo Rubbia: CERN DG ICHEP Singapore 1990 LHC pp: 1996, ep: 1998 Study LHeC and its relations to the LHC for the decisions on HEP to come in ~2010

27. Thanks To J.Dainton, P.Newman, E.Perez, F.Willeke D.Pitzl, W.Smith, O.Bruening, H.Burckart, S.Forte J.Bluemlein, U.Klein, T.Kluge, P.Kostka, A.Martin, A.Mehta, W.vanNeerven, W.Tung, .. and members of the SAC for collaboration and encouragement

28. Lepton Polarisation D.Barber

29. 105 events per pb-1 for Q2>100 Lumi ‘easy’ Low x Kinematics Small angle spectrometer, favourable over THERA kinematics cf THERA book for detector concept [also W.Bartel Aachen 1990] Dramatic extension of low x kinematic range

30. Hi q2 kinematics Maximum luminosity in current design achieved with focusing magnets close to IP (9o cut) two detectors or detector versions required [cf THERA] Lowx with 1032 , highQ with 1033 [higher in upgraded LHC]

31. Strange quark distribution Wu-Ki Tung. HERA LHC 3/07 Wu-Ki Tung. DIS04, and recent developments

32. Parton interaction developments at the energy frontier*) 1970 2000 2015 DIS Bjorken scaling – QPM, PV (high) parton densities neutral currents diffraction asymptotic freedom …. QCD ? e+e- J/Ψ 3 neutrinos … ILC gluons ….. electroweak theory pp charm, W,Z,bottom top LHC … *) incomplete The standard model emerged as a result of decades of joint research in e+e- , ep, pp/hh accelerator experiments, including quark and neutrino mixing. Low x physics related to AA and to high energy neutrino physics. There is no quantitative understanding of Tevatron data without HERA. Physics is more than the often quoted “dualism” between e+e- and pp.