Exclusive Central Production in Proton-Proton Collisions: from the - PowerPoint PPT Presentation

Exclusive Central Production in Proton-Proton Collisions: from the ISR to the Tevatron to the LHC Mike Albrow Fermilab 1 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Exclusive Central Production in Proton-Proton Collisions: from Glueballs to Higgs Bosons Mike Albrow (Fermilab) ISR – Tevatron -- LHC p p p p + W π + G? H? π − - W p p p p 1) Introduction 2) Diffractive Excitation of High Masses (Jets,W,Z) – CDF/D0 3) Central Exclusive Production: + − + − e e , μ μ , J/ ψ / ψ (2S), Υ , JJ + π − + − π ( , , ) K K p p 4) LHC: Study of Higgs through p+H+p, WW and ZZ, Excl.Z? FP420: R&D project; proposing extensions to ATLAS & CMS. 2 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

ISR = Intersecting Storage Rings, started 1971 First colliding proton beams. p p (31 GeV/c) p (31 GeV/c) p (28 GeV/c) Centre of Mass Energy = 63 GeV Centre of Mass Energy = 7.4 GeV Equivalent to beam of 2110 GeV + fixed p target “Into the realm of cosmic rays!” First collisions ... no detectors installed! ... put in 4 counters! L R COLLISIONS! t(L) – t(R) Experiment 101 Emulsions on a toy train set! 3 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

2008: LHC = Large Hadron Collider ≡ 8 17 10 GeV=10 eV 7 TeV = 7000 GeV 7 TeV = 7000 GeV ≈ 20 cf. cosmic cut off 10 eV ATLAS ~ 2500 physicists! One of four experiments. 4 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Meanwhile, back at the ISR in 1972 ... British + USA Intersection I-2: Muon Detector W? p p Medium Angle Spectrometer Wide Angle Small Angle Spectrometer Spectrometer British-Scandinavian CERN-Holland- Lancaster-Manchester Nobody knew what to do with complete multi-particle (~ 10+) final states. μ π , , , , ... Study “inclusive” particle production: pp � + “anything”. e K p J ψ Muon Detector: Looking for W(~3-4 GeV!) ... missed / Wide Angle Spectrometer: co-discovered high (quark scattering) p T Small Angle Spectrometer: discovered high mass (14 GeV) diffraction p x ~ 0.95 p = OUT x p M ~ 14 GeV IN 5 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Small Angle Spectrometer: Forward proton spectra p = L x Feynman p beam Feynman scaling: σ = 3 d ( , ) not E f x p s 3 F T dp Discovery of high-x, scaling peak x > 0.95 M p < = M 0.05 0.22 s s M up to about 1.6 GeV at AGS/PS 0.95 14 GeV at ISR p = L 440 GeV at Tevatron x Feynman p 3100 GeV at LHC beam 6 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Forward Proton Spectrometers: ISR � LHC ISR (1971) Small Angle Spectrometer Gas Cerenkovs and tracking Magnets and Spark Chambers p (scattered) 20cm x 20cm ~ 2m p (beam) SEPTUM 30 GeV/c ~ 15m, dp/p ~ 0.5% LHC (2009 – FP420 2011) 20 mm x 6 mm 120m of 8T dipoles FP420 QUADS, SEPs 3-24 mm 10m 7000 GeV/c 420m, dp/p ~ 0.01% High Precision (5-10 μ m) tracking High Precision (~10 ps) timing Cerenkovs 7 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Central Diffractive Excitation Theoretically (Regge theory) if: happens, so should: x > 0.95 x > 0.95 < M 0.05 s M up to about 3 GeV at ISR … both protons coherently scattered 100 GeV at Tevatron H,WW 700 GeV at LHC p p Exchanged 4-momentum must have no electromagnetic charge or strong charge (colour), & spin >=1 γ + o r ( , ) = IP (pomeron) p p g g g g Central state Quantum Numbers restricted. “Vacuum Excitation” W/Z exchange allowed, but p would break up. 8 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Central Exclusive Production pp � p X p where X is a simple system completely measured π + At CERN ISR p p Glueball Search π − μ + At Tevatron & LHC γγ → μ μ + − μ − + − γ → ψ Υ → μ μ , γ IP → γγ gg γ through q-loops (box) + colour bleaching (g) W γγ → → → ; , WW H WW H ZZ → → ; , H bb BSM WW SUSY etc W 9 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Central Exclusive Production in Different Machines + e − In collisions (through LEP energies � I L C) : e + − γγ → , l l q q � hadrons, and at high (ILC) energy: WW � WW, WW � Z,H ; WZ � W In ep collisions (HERA) : ρ φ ψ Υ , , / , gamma-IP � vector mesons J γγ → + − ( too but buried?) q q l l pp (p p ) In (ISR � Tevatron and LHC) : γ γ IP IP � hadrons (can be single hadron), q-loop � Higgs, γ ψ , ψ ' -IP � vector mesons (.. ,Y, Z(allowed but tiny)?) γγ � l+l- ( too but buried?) q q New in CDF γγ → + − In AA (RHIC, LHC) mainly (E-fields) l l γ -IP and IP+IP 10 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

ISR: Axial Field Spectrometer (R807) First sophisticated high-pT spectrometer in pp. Forerunner of p-pbar collider experiments. |eta| <~ 1 Uranium-scintillator full-azimuth calorimeter 37%/sqrt(E) hadron showers Axial Field Magnet (~Helmholtz coils) ET = 0-11.5/63 GeV ET ET = 35-40/63 GeV Circularity (2D-sphericity) Jets in hadron-hadron co-discovered Phys.Lett B128 (1983) 354 with UA2,UA1 (1982 Paris) eta phi 11 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Low Mass Central Exclusive Production pp � p X p Search for “Glueballs” ISR = 63 GeV s X fully measured { }as distinct from{ } gg qq π + p p + nothing else π − Axial Field Spectrometer (R807) Added very forward drift chambers Central drift chamber half 12 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

π + π − Central Exclusive Production (AFS) No ρ 3500 events/25 MeV 0 (980) f G(1710)?? Structures not well understood beyond f(980). Not studied at higher s φφ Pity: would be great + − Also K K and p p for G-spectroscopy αα elastic scattering + π − π ( ) M on-line dip! α α π π α α 13 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Exclusive Central Hadron States at ISR Birmingham did much of this at Omega facility, lower s Axial Field Spectrometer: = ≤ f(980) s 63 GeV, Δ y 3 ? + − + − π π π , , , 4 K K pp G PC + ++ Q.No. Filter: I J =0 even + − M( π π ) What about, among others: 0 0 0 0 K K , D D , D D ,... Λ Λ , Σ Σ , Ω Ω ,...! S S S S Pomeron ~ gg is flavor-blind, mostly depends on masses. CDF detector equal to best in world, Tevatron to best place! Hope to do it, but … 14 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

CDF Detector at Fermilab Tevatron MiniPlugs MiniPlugs 980 GeV 980 GeV p pbar 15 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Installed very forward Beam Shower Counters (BSC) for rapidity gaps and scintillating fiber trackers in Roman pots for pbar detection Not at all to scale! Roman pot detectors 20mm x 20mm 55 m downstream. Not used for most of this (acceptance). Beam Shower Counters BSC tight around pipe. η Full coverage –7.4 < < +7.4 p → π p ππ ; , etc vetoed n 16 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Central tracking: Silicon strips & Drift Chamber ~ 720,000 strips, Drift chamber 25 μ m with 50 μ m readout 96 layers � 30,240 sense wires 40 μ m gold-plated tungsten Surrounded by lead/iron ADC and TDC each end scintillator sandwich calorimeter Resolution ~ 150 μ m/wire for energy measurement 17 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Diffractive W and Z Production p “quasi-elastic” W W D0 W produced but p “stays intact” CDF: Diff. W Non-Diff W = ± (1.15 0.55)% D0 also sees diffractive W and Z all consistent with 1% diffractive Z Should be much larger at LHC η = − ( ) 2.3 4.3 LO η = − ( ) 3.0 5.2 CAL μν z ν M ( ) : no p ( ) ambiguity 18 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008

Central Exclusive Production in CDF pp � p X p where X is a simple system completely measured X p p CDF : e+e-, γγ , μ + μ -, J/ ψ , ψ (2S), χ _c, Υ …. Z? JJ l ~ ~ LHC: Z, H, W+W-, ….. l 19 Mike Albrow Central Exclusive Production in Proton Proton Collisions: ISR-Tevatron- LHC Univ.Birmingham Oct 2008