Diffraction and Exclusive (Higgs?) Production

Transcription

1 Diffraction and Exclusive (Higgs?) Production from CDF to LHC Konstantin Goulianos The Rockefeller University Les Rencontres de hysique de la Valle e d Aoste 4-10 March 007, La Thuile, Italy Recent references: resented at Diffraction 006 Diffraction at the Tevatron: CDF results htt://os.sissa.it//archive/conferences/035/016/diff006_016.df Renormalized diffractive arton densities htt://os.sissa.it//archive/conferences/035/044/diff006_044.df

2 OVERVIEW La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos

3 The Standard Model La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 3

4 Contents Introduction Elastic and Total Cross Sections Diffraction Exclusive Production La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 4

5 - Interactions Non-diffractive: Color-exchange Diffractive: Colorless exchange with vacuum quantum numbers raidity ga Incident hadrons acquire color and break aart CONFINEMENT P O M E R O N Incident hadrons retain their quantum numbers remaining colorless seudo- DECONFINEMENT Goal: understand the QCD nature of the diffractive exchange La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 5

6 Elastic Scattering PROTON-PROTON ELASTIC SCATTERING ' DIFFRACTION PATTERN dσ dt PROTON BEAM TARGET PROTON R dσ (θ ) bt 4 dt R = ~ e 1 m π ~ e b 13 GeV c La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 6

7 Diffraction Dissociation R T P 0 R L Δ P T, Δ P L P 0 m M Momentum loss fraction ξ ΔP = P L L = m m M s COHERENCE π ξ < 0. 1 CONDITION Tevatron M 0.6 TeV LHC 4.4 TeV d d σ dt dm t= 0.05 ξ< 0.1 But why dσ dm ~ 1 M? La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 7

8 Raidity Gas X X ξ φ Particle roduction dσ dδη ln M X t= 0 ln s constant dσ dm Raidity ga ~ -ln ξ 1 M dσ dξ ~ 1 ξ η La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 8

9 Diffractive Processes Elastic scattering σ T =Im f el (t=0) Total cross section φ GAP η OPTICAL THEOREM φ η SD DD DPE SDD=SD+DD La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 9

10 Raidity Gas in Fireworks La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 10

11 The Physics Elastic and Total Cross Sections:. and X Fundamental Quantum Mechanics Froissart Unitarity Bound.σ T < C ln s Otical theorem..σ T ~Im f(t=0) Disersion relations...re f(t=0)~im f(t=0) Is sace-time discrete? Measure σ T Diffraction Dissociation: X, XgX, X, XgX, Non-erturbative QCD Soft & hard diffraction Factorization Multi-ga diffraction Diffraction in QCD:. what is the Pomeron? Dark energy? and ρ-value at LHC! Exclusive Production:... +H (jet+jet, γ+γ,, H 0 ) Discovery channel Diffractive Higgs roduction at the LHC (?) La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 11

12 Tevatron Exeriments Ex Info Roman Pots El σ T Soft diffraction Hard diffraction E710/811 Scint. Counters, bar x x sd CDF-0, bar x x sd CDF-I bar sd,dd,de,sdd JJ,b,J/ψ,W,JGJ CDF-II bar sd D0-I D0-II, bar x x sd,de, JJ,W,Z,JGJ Exclusive JJ,γγ,... JJ,W,Z,JGJ, JJ,W,Z,JGJ, Exclusive??? La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 1

13 CDF Run 1-0 ( ) Elastic, diffractive, and total cross 546 and 1800 GeV Roman Pot Sectrometers CDF-I Roman Pot Detectors Scintillation trigger counters Wire chamber Double-sided silicon stri detector Roman Pots with Trackers u to η = 7 La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 13

14 Run-IC CDF-I Run-IA,B η = 0 CENTRAL MUON UPGRADE STEEL ABSORBER CENTRAL MUON CENTRAL HADRON Central Muon Extension END WALL HADRON η = 0.9 CDF Detector DIPOLE MAGNETS beam - CDF CENTRAL EM CES CPR SOLENOID CENTRAL TRAKCING CHAMBER Vertex Tracking Chamber Silicon Vertex Detector INTERACTION POINT END PLUG EM END PLUG HADRON η =.4 BBC Z EM Forward (Not-To-Scale) HADRON η = 4. x=1 x<0.97 ROMAN POTS at 57 m Scintillator fiber xy-tracker 70 μ itch, m lever arm Accetance: 0 < t < 1, 0.03< ξ < 0.1 Forward Detectors BBC 3.<η<5.9 FCAL.4<η<4. La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 14

15 CDF-II ROMAN POT DETECTORS BEAM SHOWER COUNTERS: Used to reject ND events MINIPLUG CALORIMETER La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 15

16 The CDF La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 16

17 RP BSC4 CDF & D0 - Run II CDF BSC3 BSC BSC BSC3 RP3 RP1 57 CDF & D0 COMPLIMENTARY COVERAGE D S Q 4 Q 3 Q Q Q 3 Q 4 MP 3.5<η<5.5 Z(m) BSC1 5.5<η< D0 P 1U S P O D D1 Q Q 3 Q 4 Q 4 Q 3 Q D S A S A 1 P 1D P I LM.5<η<4.4 Z(m) VC 5.<η< From Barreto s talk in small-x La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 17

18 ELASTIC AND TOTAL CROSS Tevatron: CDF and E710/811 use luminosity indeendent method σ Otical theorem T ~ 1 L 1 1+ ρ dn dt el otical theorem t= 0 & σ T ~ 1 L ( N + N ) el inel σ T = 16π 1+ ρ dn dt el t= 0 N el 1 + N inel Alert: background N inel yields small σ T undetected N inel yields large σ T La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 18

19 σ T and ρ-values from PDG ρ = ratio of real/imaginary arts of elastic scattering amlitude at t=0 CDF E710 E811 CDF and E710/811 disagree CDF & UA4 E811 σ T Im f el (t=0) otical theorem disersion relations Re f el (t=0) N. Khuri and A. Martin: measuring ρ at the LHC tests discreteness of sace-time La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 19

20 Total Cross Sections: Regge fit CDF E710 Born level CMG: Covolan, Montagna, and G PLB 389 (1995) 176 DL Simultaneous Regge fit to, π, and K x-sections using the eikonal aroach to ensure unitarity σ S ε ε = / σ LHC = 115 TeV La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 0

21 Other Aroaches eg, M. Block, arxiv:he-h/ (006) fit data using analyticity constraints M. Block and F. Halzen, Phys. Rev. D 7, σ T (LHC) = ± 1. mb Recall CMG Regge fit: 115 mb La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 1

22 TOTEM LHC Total Cross Section, Elastic Scattering, and Diffraction Dissociation Aim at 1% accuracy on σ T RP stations CMS RP stations CMS/TOTEM LOI: Prosects for Diffractive and Forward Physics at the LHC La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos

23 SOFT DIFFRACTION Key words: renormalization scaling QCD multi-ga dark energy??? La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 3

24 Renormalization Factorization Regge theory σ SD exceeds σ T at s TeV. σ dtdξ Renormalization Pomeron flux integral (re)normalized to unity KG, PLB 358 (1995) 379 d SD = f IP/ (t, ξ) σ IP (M X Pomeron flux ) σ SD ~ s ε ξ 0.1 min 0 t= f IP/ (t,ξ) dξ dt = 1 La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 4

25 A Scaling Law in Diffraction KG&JM, PRD 59 (1999) renormalization dσ dm s (M ε 1+ ε Indeendent of S over 6 orders of magnitude in M! ) 1 std. and renorm. flux fits Δ ε Δ = 0.05 Δ = 0.15 renorm. flux rediction GeV (0.01 < ξ < 0.03) 0 GeV (0.01 < ξ < 0.03) 546 GeV (0.005 < ξ < 0.03) 1800 GeV (0.003 < ξ < 0.03) 1 (M ) 1+Δ 546 GeV std. flux rediction 1800 GeV std. flux rediction Factorization breaks down so as to ensure M -scaling! La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 5

26 The QCD Connection σ φ ε Δy T ( s) = σ o e = Δy = ln s σ o s ε y Total cross section: ower law increase versus s 1/α s The exonential rise of σ T (Δy ) is due to the increase of wee artons with Δy (E. Levin, An Introduction to Pomerons,Prerint DESY 98-10) Im f el φ ( s, t) Δy = ln s e ( ε + α t ) Δy y Elastic cross section: forward scattering amlitude La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 6

27 Single Diffraction in QCD (KG, he-h/005141) t Δy Δy dσ dm REGGE s ε 1+ ε (M ) indeendent variables: d dt t, Δy σ = C F ( t) dδy { ( ε + α t ) Δy} { ε Δy e κ σ e } Ga robability ε Δy ~ e Δy= ln s Δy Renormalization removes the s-deendence SCALING La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 7 color factor min o ε Δy s s ε

28 Multi-ga Renormalization (KG, he-h/005141) 5 indeendent variables d 5 i= 1 5 σ dv i = C F ( t1) i= 1- Δy= Δy ε Δy ~ e ln s Δy s min Δy 1 Δ 1 Δy 1 ε s ε Same suression as for single ga! La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 8 y y 1 y t Δy = Δy 1 + Δy Ga robability t Δy { ( ε + α t ) } i Δyi ε ( Δy1 +Δy ) e κ σ e { } o color factors Sub-energy cross section (for regions with articles)

29 Central and Double CDF IP M 1 M η min dn dη η max ln M 1 ln M ln s η Double Diffraction Dissociation One central ga η _ 0 η η IP IP Double Pomeron Exchange Two forward gas IP t IP t M 1 M η min η max 0 ln M 1 ln M ln1/ξ ln s ln s η SDD: Single+Double Diffraction One forward + one central ga La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 9

30 Central & Double-Ga CDF Results events s=1800 GeV Differential shaes agree with Regge redictions DATA DD + non-dd MC non-dd MC 10 s = 1800 GeV ξ t- DD SDD DPE 1.0 GeV Δη 0 =η max -η min events s=1800 GeV DATA SDD + SD MC SD MC Δη 0 ex =η max -η min Number of Events er Δlogξ = CDF Preliminary M X ( GeV ) Data DPE MC SD MC DPE+SD MC ξ X σ DD (mb) for Δη > One-ga cross sections are suressed Two-ga/one-ga ratios are κ = CDF UA5 (adjusted) Regge Renormalized ga ga fraction Δη > CDF: one-ga/no-ga CDF: two-ga/one-ga Regge rediction Renorm-ga rediction -ga 1-ga Fraction of Events with ξ < CDF Data: DPE/SD ratio (Preliminary) Regge + Factorization Ga Probability Renorm. Pomeron Flux Renom s (GeV) sub-energy s --, (GeV) s (GeV) La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 30

31 Dark Energy Non-diffractive interactions Raidity gas are formed by multilicity fluctuations: P( Δy) = e ρδy, dn dy P(Δy) is exonentially suressed ρ = articles Diffractive interactions Raidity gas at t=0 grow with Δy: Δy lnξ = ln P( Δy) t = 0 ~ s ln M εδy e ε: negative article density! Gravitational reulsion? La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 31

32 HARD DIFFRACTION dn/dη Diffractive fractions Diffractive structure function factorization breakdown Restoring factorization Q deendence t deendence Hard diffraction in QCD η JJ, W, b, J/ψ La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 3

33 Diffractive CDF ( + X ) + ga Fraction: SD/ND ratio at 1800 GeV W JJ b Fraction(%) 1.15 (0.55) 0.75 (0.10) 0.6 (0.5) All ratios ~ 1% ~ uniform suression ~ FACTORIZATION! J/ψ 1.45 (0.5) La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 33

34 Diffractive Structure Function: Breakdown of QCD Factorization β = momentum fraction of arton in Pomeron H1 CDF The diffractive structure function at the Tevatron is suressed by a factor of ~10 relative to exectation from df s measured by H1 at HERA Using reliminary df s from Similar suression factor as in soft diffraction relative to Regge exectations! La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 34

35 Restoring QCD Factorization ND jet jet SD DPE η _ 0 jet 0 jet jet 0 η jet η IP IP IP R(SD/ND) R(DPE/SD) DSF from two/one ga: factorization restored! F D jj (β) from DPE/SD, 0.01 ξ from SD/ND, ξ β The diffractive structure function measured on the roton side in events with a leading antiroton is NOT suressed relative to redictions based on DDIS La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 35

36 Diffractive Structure Function: Q deendence E T jet ~ 100 GeV! Small Q deendence in region 100 < Q < 10,000 GeV Pomeron evolves as the roton! La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 36

37 Diffractive Structure Function: t- deendence Fit dσ/dt to a double exonential: No diffraction dis No Q deendence in sloe from inclusive to Q ~10 4 GeV Same sloe over entire region of 0 < Q < 4,500 GeV across soft and hard diffraction! La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 37

38 Hard Diffraction in QCD Derive diffractive from inclusive PDFs and color factors dee sea valence quarks valence quarks antiroton x=ξ roton La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 38

39 EXCLUSIVE PRODUCTION Measure exclusive jj & γγ Calibrate redictions for H roduction LHC Bialas, Landshoff, Phys.Lett. B 56,540 (1991) Khoze, Martin, Ryskin, Eur. Phys. J. C3, 311 (00); C5,391 (00);C6,9 (00) C. Royon, he-h/ B. Cox, A. Pilkington, PRD 7, (005) OTHER Clean discovery channel H KMR: σ H (LHC) ~ 3 fb S/B ~ 1 if ΔM ~ 1 GeV Search for exclusive dijets: Measure dijet mass fraction R jj = M X M ( all calorimeters) Look for signal as M jj 1 jj Search for exclusive γγ 3 candidate events found 1 (+/-1) redicted from ExHuME MC* background under study * See talk by V. Khoze La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 39

40 Exclusive Dijet Signal D Dijet fraction all jets b-tagged dijet fraction I J E T S Excess over MC redictions at large dijet mass fraction Exclusive b-jets are suressed by J Z = 0 selection rule La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 40

41 R JJ (excl): Data vs MC ExHuME (KMR): gg gg rocess uses LO QCD Exclusive DPE (DPEMC) non-qcd based on Regge theory Shae of excess of events at high R jj is well described by both models La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 41

42 jj excl : Exclusive Dijet Signal COMPARISON Inclusive data vs b/c-jet data vs inclusive La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 4

43 JJ excl : x-section vs E T (min) Comarison with hadron level redictions ExHuME (red) Exclusive DPE in DPEMC (blue) La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 43

44 JJ excl : cross section redictions ExHuME Hadron-Level Differential Exclusive Dijet Cross Section vs Dijet Mass (dotted/red): Default ExHuME rediction (oints): Derived from CDF Run II Preliminary excl. dijet cross sections Statistical and systematic errors are roagated from measured cross section uncertainties using ExHuME M jj distribution shaes. La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 44

45 Looking LHC TOTEM/CMS ATLAS FP40 roject: htt:// Measure rotons at 40 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 develoment Physics aim : + X + (Higgs, New hysics, QCD studies) Status: Project funded by the UK La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 45

46 Summary TEVATRON what we have learnt M scaling Non-suressed double-ga to single-ga ratios Pomeron: comosite object made u from underlying df s subject to color constraints LHC - what to do Elastic and total cross sections & ρ-value High mass ( 4 TeV) and multi-ga diffraction Exclusive roduction (FP40 roject) Reduced bgnd for std Higgs to study roerties Discovery channel for certain Higgs scenarios La Thuile07, -0 March Diffraction and Exclusive (Higgs?) Production from CDF to LHC K. Goulianos 46