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Diffractive and Total Cross Sections @ Tevatron and LHC

Diffractive and Total Cross Sections @ Tevatron and LHC. K. Goulianos The Rockefeller University.  CDF results are presented on behalf of the CDF Collaboration . HCP 2006 Duke University, NC, USA, 22-26 May 2006. Contents. Introduction Total Cross Sections Diffraction

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Diffractive and Total Cross Sections @ Tevatron and LHC

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  1. Diffractive and Total Cross Sections @ Tevatron and LHC K. Goulianos The Rockefeller University  CDF results are presented on behalf of the CDF Collaboration HCP 2006Duke University, NC, USA,22-26 May 2006

  2. Contents • Introduction • Total Cross Sections • Diffraction • Exclusive Production Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  3. Incident hadrons acquire color and break apart POMERON CONFINEMENT p-p Interactions Non-diffractive: Color-exchange Diffractive: Colorless exchange with vacuum quantum numbers rapidity gap Incident hadrons retain their quantum numbers remaining colorless pseudo- DECONFINEMENT Goal: understand the QCD nature of the diffractive exchange Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  4. Elastic Scattering Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  5. COHERENCE CONDITION Diffraction Dissociation Momentum loss fraction x< 0.1 @Tevatron MX 600 GeV @ LHC  4.4 TeV Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  6. xp p p p X X ln s f Particle production Rapidity gap ln MX2 -ln x h Rapidity Gaps Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  7. Diffractive pp Processes sT=Im fel (t=0) Elastic scattering Total cross section f f OPTICAL THEOREM GAP h h DD DPE SDD=SD+DD SD Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  8. Rapidity Gaps in Fireworks Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  9. The Physics • Elastic and Total Cross Sections:……….pppp and ppX • Fundamental Quantum Mechanics • Froissart Unitarity Bound……….sT < C ln2s • Optical theorem………………………..sT ~Im f(t=0) • Dispersion relations………………....Re f(t=0)~Im f(t=0) • Is space-time discrete?  Measure the r-value at the LHC! • Diffraction Dissociation:………………pppX, pppXp, ppXGX, pppXGX • Non-perturbative QCD • Soft & hard diffraction • Factorization • Multi-gap diffraction • Diffraction in QCD:…….……what is the Pomeron? • Dark energy? • Exclusive Production:………………….…..pppp+A (jet+jet, g+g, …, H0) • Discovery channel • Diffractive Higgs production at the LHC (?) Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  10. Tevatron Experiments Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  11. CDF Run 1-0 (1988-89) Elastic, diffractive, and total cross section @ 546 and 1800 GeV Roman Pot Spectrometers CDF-I • Roman Pot Detectors • Scintillation trigger counters • Wire chamber • Double-sided silicon strip detector Roman Pots with Trackers up to |h| = 7 Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  12. Run-IC CDF-I Run-IA,B beam Forward Detectors BBC 3.2<h<5.9 FCAL 2.4<h<4.2 Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  13. ROMAN POT DETECTORS BEAM SHOWER COUNTERS: Used to reject ND events MINIPLUG CALORIMETER CDF-II Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  14. p S S CDF & D0 - Run II p CDF RP2 BSC4 BSC3 BSC2 BSC2 BSC3 D Q4 Q3 Q2 Q2 Q3 Q4 Z(m) RP3 RP1 MP 3.5<η<5.5 BSC1 5.5<η<7.5 0 57 23 32 23 32 CDF & D0: COMPLIMENTARY COVERAGE D0 P1U P2O Q4 Q3 Q2 Q2 S D Q3 Q4 S A1 D1 A2 D2 P1D P2I Z(m) LM 2.5<η<4.4 VC 5.2<η<5.9 57 0 59 23 33 23 33 From Barreto’s talk in small-x Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  15. ELASTIC AND TOTAL CROSS SECTIONS At Tevatron: CDF and E710/811  use luminosity independent method Optical theorem optical theorem • Alert: • background Ninel yields small sT • undetected Ninel yields large sT Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  16. sT and r-values from PDG r = ratio of real/imaginary parts of elastic scattering amplitude at t=0 CDF CDF and E710/811 disagree E710 E811 sT optical theorem Im fel(t=0) dispersion relations Re fel(t=0) CDF & UA4 E811 N. Khuri and A. Martin: measuring r at the LHC tests discreteness of space-time Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  17. Total Cross Sections: Regge fit CDF E710 CMG: Covolan, Montagna, and G PLB 389 (1995) 176 Born level Simultaneous Regge fit to pp, pp, and Kp x-sections using the eikonal approach to ensure unitarity s  Se e = 1.104 +/- 0.002  sLHC= 115 mb @14 TeV DL Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  18. Elastic/Total and r-values: Regge fit Covolan, Montagna, and G PLB 389 (1995) 176 • Agreement with data on: • b-slopes • sel/sT • r-values • Unitarity assured Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  19. Recall CMG Regge fit: 115 mb Other Approaches eg, M. Block, arXiv:hep-ph/0601210(2006)  fit data using analyticity constraints M. Block and F. Halzen, Phys. Rev. D 72, 036006 • sT (LHC) = 107.3 ± 1.2 mb Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  20. TOTEM experiment @ LHC Total Cross Section, Elastic Scattering, and Diffraction Dissociation Aim at 1% accuracy on sT RP stations CMS RP stations Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  21. DIFFRACTION • Soft & hard diffraction • Factorization / renormalization • Multi-gap diffraction • Diffraction in QCD • Dark energy ??? Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  22. A unitarity issue Factorization  Pomeron flux • Regge theory sSD exceeds sT at • Renormalization Pomeron flux integral (re)normalized to unity KG, PLB 358 (1995) 379 Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  23. renormalization 1 A Scaling Law in Diffraction KG&JM, PRD 59 (1999) 114017  Independent of S over 6 orders of magnitude in M2 ! Factorization breaks down so as to ensure M2-scaling! Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  24. f y The QCD Connection f Total cross section: power law increase versus s y ~1/as The exponential rise of sT(Dy’) is due to the increase of wee partons with Dy’ (E. Levin, An Introduction to Pomerons,Preprint DESY 98-120) Elastic cross section: forward scattering amplitude Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  25. Single Diffraction in QCD (KG, hep-ph/0205141) t 2 independent variables: color factor Gap probability Renormalization removes the s-dependence SCALING Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  26. 5 independent variables color factors Gap probability Sub-energy cross section (for regions with particles) Same suppression as for single gap! Multi-gap Renormalization (KG, hep-ph/0205141) Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  27. Central and Double Gaps @ CDF • Double Diffraction Dissociation • One central gap • Double Pomeron Exchange • Two forward gaps • SDD: Single+Double Diffraction • One forward + one central gap Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  28. Differential shapes agree with Regge predictions DD SDD DPE • One-gap cross sections are suppressed • Two-gap/one-gap ratios are Central & Double-Gap CDF Results Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  29. Non-diffractive interactions Diffractive interactions Rapidity gaps are formed by multiplicity fluctuations: Rapidity gaps at t=0 grow with Dy: 2e: negative particle density! P(Dy) is exponentially suppressed Gravitational repulsion? Dark Energy Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  30. dN/dh h HARD DIFFRACTION • Diffractive fractions • Diffractive structure function  factorization breakdown • Restoring factorization • Hard diffraction in QCD JJ, W, b, J/y Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  31. Diffractive Fractions @ CDF Fraction(%) Fraction: SD/ND ratio at 1800 GeV All ratios ~ 1% ~ uniform suppression ~ FACTORIZATION ! W 1.15 (0.55) JJ 0.75 (0.10) b 0.62 (0.25) J/y 1.45 (0.25) Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  32. Diffractive Structure Function:Breakdown of QCD Factorization b = momentum fraction of parton in Pomeron The diffractive structure function at the Tevatron is suppressed by a factor of ~10 relative to expectation from pdf’s measured by H1 at HERA Similar suppression factor as in soft diffraction relative to Regge expectations! H1 CDF Using preliminary pdf’s from Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  33. R(SD/ND) R(DPE/SD) DSF from two/one gap: factorization restored! Restoring QCD Factorization The diffractive structure function measured on the proton side in events with a leading antiproton is NOT suppressed relative to predictions based on DDIS Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  34. Diffractive Structure Function:Q2 dependence ETjet ~ 100 GeV ! • Small Q2 dependence in region 100 < Q2 < 10,000 GeV2 • Pomeron evolves as the proton! Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  35. Diffractive Structure Function:t- dependence Fit ds/dt to a double exponential: • No diffraction dips • No Q2 dependence in slope from inclusive to Q2~104 GeV2 • Same slope over entire region of 0 < Q2 < 4,500 GeV2 across soft and hard diffraction! Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  36. p p valence quarks antiproton antiproton Hard Diffraction in QCD deep sea valence quarks Derive diffractive from inclusive PDFs and color factors x=x proton Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  37. H EXCLUSIVE PRODUCTION Measure exclusive jj & gg  Calibrate predictions for H production rates @ LHC Bialas, Landshoff, Phys.Lett. B 256,540 (1991) Khoze, Martin, Ryskin, Eur. Phys. J. C23, 311 (2002); C25,391 (2002);C26,229 (2002) C. Royon, hep-ph/0308283 B. Cox, A. Pilkington, PRD 72, 094024 (2005) OTHER………………………… KMR: sH(LHC) ~ 3 fb S/B ~ 1 if DM ~ 1 GeV Clean discovery channel Search for exclusive gg Search for events with two high ET gammas and no other activity in the calorimeters or BSCs Search for exclusive dijets: Measure dijet mass fraction Look for signal as Mjj 1 Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  38. Exclusive Dijet and gg Search Dijet fraction – all jets b-taqged dijet fraction DIJETS Exlusive b-jets are suppressed by JZ= 0 selection rule Excess over MC predictions at large dijet mass fraction Systematic uncertainties under study: tune in this summer for results Exclusive gg Based on 3 events observed: Good agreement with KMR: Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  39. Looking forward@ LHC TOTEM/CMS ATLAS • FP420 project • Measure protons at 420 m from the IP during normal high luminosity running to be used in conjunction with CMS and ATLAS • Feasibility study and R&D for Roman Pot detector development • Physics aim :pp  p+ X + p (Higgs, New physics, QCD studies) • Status: Project funded by the UK Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

  40. Summary TEVATRON – what we have learnt • M2 – scaling • Non-suppressed double-gap to single-gap ratios • Pomeron: composite object made up from underlying pdf’s subject to color constraints LHC - what to do • Elastic and total cross sections & r-value • High mass  4 TeVand multi-gap diffraction • Exclusive production (FP420 project)  Reduced bgnd for std Higgs to study properties  Discovery channel for certain Higgs scenarios Diffractive ant Total Cross Sections @ Tevatron and LHCK. Goulianos

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