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High-energy photon collisions at the LHC -- Summary --

High-energy photon collisions at the LHC -- Summary --. Michael Klasen (LPSC Grenoble) April 25, 2008. High-energy photon collisions at the LHC -- Summary --. Michael Klasen (LPSC Grenoble) April 25, 2008. Sorry - impossible to cover all 44 talks. Introduction.

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High-energy photon collisions at the LHC -- Summary --

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  1. High-energy photon collisions at the LHC-- Summary -- Michael Klasen (LPSC Grenoble) April 25, 2008

  2. High-energy photon collisions at the LHC-- Summary -- Michael Klasen (LPSC Grenoble) April 25, 2008 Sorry - impossible to cover all 44 talks ...

  3. Introduction • Higgs production (K. Piotrzkowski): • h0: Diffractive > photoproduction • H++/--: Drell-Yan > photoproduction • SUSY particle production: gg  ll, cc • J. Ohnemus, T.F. Walsh, P.M. Zerwas, PLB 328 (1994) 369 (M. Herquet) ~ ~ ~ ~ Michael Klasen (LPSC Grenoble)

  4. Photon physics at LEP • Two phases (M. Przybycien): • LEP-I : s = 91 GeV • LEP-II: s = 161-209 GeV • Untagged events: • stotgg (L3=OPAL):Soft IP & IR, but no hard IP • Inclusive jets (L3OPAL): OPAL agrees with NLO (KKK) • Dijets (OPAL):Separate D, SR, and DR with xg • Charged hadrons (L3OPAL): HarderpT-spectrum than in gp • Single-tagged events: • Fg2: QED, hadronic, charm, as • Alt. power counting (J. Hejbal) • Double-tagged events: • Fg*2: QED, hadronic, Fe2, stotg*g* Albino, MK, Söldner-Rembold, PRL 89 (2002) 122004 PDG, JPG 33 (2006) 1 Michael Klasen (LPSC Grenoble)

  5. Photon physics at HERA • Precise experimental results (T. Schörner-Sardenius): • Hard scattering: S=½ quark vs. S=1 gluon exchange (cos q) • Photon structure: From LAC / GRV to AFG / CJK (xp <>0.1) • Proton structure: Up to 60% from gluon initial state(xg >0.8) • Large theoretical errors (J. Chyla): • Choice of ren./fact. scheme: DISg/MS; massive/ZM-VFNS/GM-VFNS • Choice of ren./fact. scale: m  mF; saddle point • Need direct contribution at NNLO (Hard ! Resummation, MC@NLO) • Prompt photons at Tevatron: Need larger pT ! • Transition from real to virtual photons: • Forward jets, particles at HERA: BFKL vs. DGLAP evolution • LHC: Elastic events. Low-mass exchanges possible ? Forward n ! Michael Klasen (LPSC Grenoble)

  6. Photon physics at ILC (1) • Photons collider (V. Telnov): • Bremsstrahlung: Low E, L • Compton scatt.: High E, L • Adjust EL, Pe,L, bL, X-angle • Measure L (gg ll, ge  ge) • Physics (A. de Roeck): • gg h,A,H  bb • ge  ce  cce • Anomalous gWtb • Detector requir.s (J. Gronberg): • Higgs:DE/E3%(jet),d5mm(b) • SUSY: Hermiticity • PLC: Affects beam pipe, endcap • Detector concepts: • US: SiD (silicon tracker) • Asia/EU: GLD/LDC  ILD (TPC) _ ~~ ~~ Michael Klasen (LPSC Grenoble)

  7. Photon physics at ILC (2) • gg at LHC • IP »g, needs S2 • Sarycheva, Ovyn • - ” - • ? • Gronberg, Schul • ? • ? • v.Manteuffel, Pierzchala • Machado • Insufficient s ? • Low rate gg ? • Favereau • Godbole ? • ? • ? • Kumar, Nystrand Michael Klasen (LPSC Grenoble)

  8. Photon physics at ILC (3) • Higgs mass: • Dm ~ 100 MeV / 1 year running ~ e+e-,pp/2 • Partial width (): • 2-7% in bb channel (needs h  bb from e+e-) 15% in e+e- • 3-10% in WW, ZZ channel (needs BR from e+e-) ~ e+e- • Determination of the phase of the   h amplitude: • 3-10% in WW, ZZ channel Unique ? • CP analysis: • h  ZZ, WW angular analysis More poss., • h  tt interference w/ QED BG, l charge asymmetries clean tests • Linear polarization • Rare decay modes: • h   !, h  Z ? Difficult • Discovery reach for H, A: • Up to 0.8 see for see ~ 800 GeV s/2-50 GeV Michael Klasen (LPSC Grenoble)

  9. Photon physics at hadron colliders • Advantages (M. Strikman, Phys. Rep. 458 (2008) 1): • RHIC, Tevatron and LHC exist • Can reach sgg 486 GeV in O+O (400 GeV at ILC) • Not only gg, but also gp / gA collisions • Disadvantages: • Much less bremsstrahlung (mp »me)  compensate with Z • Not only g, but also IP interactions  el. weak final states • Uncertain photon flux  monitor luminosity (gg  ll) • Luminosity monitor: gg  ll • CMS (J. Hollar): pT >3 (6) GeV for mm (ee), |Df| > 2.9 (2.7) (low L) • Krakow-Paris (W. Krasny): pT > 0.2 (6) GeV, |Df| > 3.1 • FP 220 / FP 420 acceptance (X. Rouby): • Proton transport in beamline: HECTOR, MAD-X • FP 420: 20 GeV < Eg < 120 GeV (DEg = 2…1 GeV) • FP 220: 120 GeV < Eg < 900 GeV (DEg = ?) • Q2 = 0.01 … 1 GeV2 (DQ2 = 0.02 … 0.06 GeV2) Michael Klasen (LPSC Grenoble)

  10. Photon spectra at hadron colliders • UPC (C. Güclü, G. Baur): • b > R1+R2 • Coherent rad. by nucleus • Strong fields: Z1Z2/137 » 1 • Vibration of nuclei • Giant dipole resonance • Large soft cross sections • ee pair production e capture beam loss • Ion beam = straight line • Integrate over b • Semiclassical/Glauber phase • gA/Ag interference Michael Klasen (LPSC Grenoble)

  11. Photon physics at RHIC • Typical process: • Low multiplicity: • 1st vertex, 2 tracks, low pT • Nuclear breakup: • Forward neutrons • STAR (B. Grube): • pp: s-channel hel. conserv. • ee: LO QED ? (Za=0.6 !) • PHENIX (S. White): J/Yee Michael Klasen (LPSC Grenoble)

  12. Photon physics at Tevatron • Motivation (J. Pinfold): • Luminosity measurement • Calibrate FP 420 • Search for cc, odderon, h0, … • CDF detector components: • Miniplug calorimeter:3.5 < |h| < 5.5 • Beam shower counters:5.5 < |h| < 6 • Roman pots not used ! • Run-II data (532 pb-1/1.48 fb-1): • gg e+e-: 16 events (QED) • IP IP gg: 3ev.(2 gg, 1 p0p0 ?) • ggm+m-, g IP  J/Y, Y’ / U:334 / 145 events Michael Klasen (LPSC Grenoble)

  13. ATLAS(Giacobbe,deRoeck): L Ar forward: 3.1<|h|<4.9 LUCID: 5.6<|h|<6 (?) ALFA: Lpp at 2-3%, stot FP420: 0.002 < x1,2 < 0.02 ALICE (R. Schicker): Hadronic central: |h|<0.9 Muon spectr.: 2.5<|h|<4(?) Forward veto: 1<|h|<4 (5) CMS(Grothe,deRoeck): Hadronic forward: 3<|h|<5 CASTOR: 5.2<|h|<6.6 TOTEM: Lpp at 1%, stot FP420: Indispensable for gg Physics (Grothe, Tasevsky): qq  ll: PDFs at x1» x2 gg  jj: BFKL evolution, S2 g g ll: L at 4%, cal. FP420 gO/IPU:ds/dpT2,cal.tag. gO/IP  pp, KK: C = 1 g/IPg/IPh,H,A:Dm/m,CP ATLAS, CMS & ALICE forward detectors Michael Klasen (LPSC Grenoble)

  14. Factorisation breaking in diffraction • DIS events: 10-20% diffractive • Hard scale: pQCD applicable • Factorisation: • Proven in DIS (Collins et al.) • Broken in pp (Tevatron) • NLO DGLAP fits (A. Bruni): • H1 2006 fit A, B • Martin, Ryskin, Watt • ZEUS LPS + charm • Singlet well constrained • Gluon badly constrained (75%) • D* and dijets in DIS and gp: • D*: Factorisation works in DIS • Also in gp ! (direct dominates) • Dijets in DIS sensitive to fits • New H1 2007 Fit Jets Michael Klasen (LPSC Grenoble)

  15. CMS (V. Kumar): Similar distribution for mm Ntot  500  fg/A @ small x ALICE (J. Nystrand): Nr 2108, NJ/Y 105 NU 400 (only U  ee) Exclusive quarkonium production at LHC Michael Klasen (LPSC Grenoble)

  16. Exclusive VM production & DVCS at HERA • Exclusive VM (A.Bunyatyan): • Hard scale: Q2 or MVM2 • ds/dt  e-b|t|: Size of VM • DVCS: • Access to GPDs (B. Pire) • b(Q2) = A (1 - B log Q2/2) Michael Klasen (LPSC Grenoble)

  17. Inclusive quarkonium production at LHC • Color Singlet Model: • Wave function: J/Y ee • Uncanceled singularities • LO pT-distributions fail • NLO corr. large (gg, gp, pp) • Non-relativistic QCD: • Effective field theory (v2) • Non-pert. color octet operators • LO pT-distributions ok (fitted) • J/Y polarization fails • NLO corr. difficult (gg) (KKMS) • Madonia (J.P. Lansberg): • Equivalent photon approxim. • Only direct photons • Similar results for U Michael Klasen (LPSC Grenoble)

  18. Anomalouscouplingsingg  WW (1) • Eff. Lagrang. (A.v.Manteuffel): • Precision constraints from LEP • Additional Feynman diagrams: • Choice of final states: • Leptons: Clean signal • Jets: Large BR, full kinematics • Optimal observables: • Fully differential cross section • Evaluate covariance matrix • LHC photon flux: • Tag both p’s, integrate over Q2 Michael Klasen (LPSC Grenoble)

  19. Anomalouscouplingsingg  WW (2) • WWgg (T. Pierzchala): • OPAL limits LHC 1fb/10fb • WWg (O. Kepka): Michael Klasen (LPSC Grenoble)

  20. Anomalouscouplingsingg  WW (3) • WW  gg (O. Eboli): • LEP: • LHC: • Single/an.top (J.d.Favereau): • Bg.:tt;Wj,Wbb-tag,ET • |DVtb|/Vtb = 0.1, ktug < 0.05 / Michael Klasen (LPSC Grenoble)

  21. Single-W prod. (D. South): Isolated e/m and missing pT Combined H1/ZEUS analysis: H1larger l-angle acceptance Excess in large e+ data with pTX >25 GeV (H1,not ZEUS) Total cross sections andW polarization fractions agree with SM Anomalous top production: Single-W & anomalous top at HERA Michael Klasen (LPSC Grenoble)

  22. Higgs in photoproduction at LHC • gg  h (L. Sarycheva): • h  bb: • h  ZZ: • gq  hWq’ (S. Ovyn): • hW  lnbb • hW  lljj • hW  lllnnn • 3s for 100fb-1 (m=170GeV) • No discovery channel ! Dm ? Michael Klasen (LPSC Grenoble)

  23. Higgs in vector boson fusion at LHC • VBF (D. Zeppenfeld): • Event selection: • Tag forward jets • Veto central jets • Analyses: • h tt (<140), WW (>130) • 5s for L = 30 fb-1 • Backgrounds: • qq  qqWW • qq  qqZZ Michael Klasen (LPSC Grenoble)

  24. SUSY particle production at LHC ~ ~ ~ ~ • gg  l l (J. Gronberg, N. Schul): • LM1: m0 = 60 GeV • Same flavor: ee, mm • s = 2.2 fb  s = 0.7 fb • 5s discovery with 25 fb-1 • Mass resolution: few GeV • tt needs at least 100 fb-1 • gg  cc: • LM9: m0 = 1450 GeV • Different flavor: em, me • s = 3.6 fb  s = 0.07 fb • Needs at least 100 fb-1 • Backgrounds: • gg  ee, mm: Acoplanarity • gg  WW: Wgg, Wmiss Michael Klasen (LPSC Grenoble)

  25. Outlook • Jet and open light/heavy quark photoproduction: • Excellent channels to constrain nuclear PDFs  adapt NLO codes ? • Top charge determination in gg  tt ? (U. Baur et al.: qq/gg  ttg) • Vector meson production: • Very sensitive to gluon density • Determine Pomeron slope / discover Odderon • Distinguish CSM / NRQCD • Gauge boson production: • Single Z: sincl. = 102sSD = 104sPHP = ? sDPE • W pairs: Different effective Lagrangians, old limits  Comparison ? • Higgs production: • Hopeless in gg, difficult in gp • SUSY Higgses ? • SUSY particles: • Sleptons promising • Gauginos difficult  Squarks (IP), gluinos (1-loop) hopeless ? • R-parity violation, other BSM models ? Michael Klasen (LPSC Grenoble)

  26. Instructions for Nucl. Phys. B Proc. Suppl. • 8 pages per contributed talk (= 30’) • 12 pages per review talk (> 30’) • No color figures • Latex instructions / macros will be mailed by Elsevier • Strict deadline: May 31, 2008 • Free copy will be sent to allspeakers in fall THANK YOU ALL FOR COMING – SEE YOU NEXT SUMMER IN BELGIUM ! Michael Klasen (LPSC Grenoble)

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