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TOTEM: Early Diffractive Physics at the LHC

TOTEM: Early Diffractive Physics at the LHC. Jim Whitmore Penn State University. INFN Sezione di Bari and Politecnico di Bari, Bari, Italy Case Western Reserve University, Cleveland, Ohio,USA CERN, Geneva, Switzerland Estonian Academy of Sciences, Tallinn, Estonia

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TOTEM: Early Diffractive Physics at the LHC

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  1. TOTEM: Early Diffractive Physics at the LHC Jim Whitmore Penn State University INFN Sezione di Bari and Politecnico di Bari, Bari, ItalyCase Western Reserve University, Cleveland, Ohio,USA CERN, Geneva, Switzerland Estonian Academy of Sciences, Tallinn, Estonia Università di Genova and Sezione INFN, Genova, Italy Università di Siena and Sezione INFN-Pisa, Italy University of Helsinki and HIP, Helsinki, Finland Academy of Sciences, Praha, Czech Republic; Warsaw University of Technology, Plock,Poland Penn State University, University Park, USA Brunel University, Uxbridge, UK on behalf of the TOTEMCollaboration http://totem.web.cern.ch/Totem/ DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  2. TOTEM Physics • Total cross-section stotwith a precision of 1% • Elastic pp scattering • in the range: 10-3 < |t| = (p )2 < 10 GeV2 • Forward Physics: • Diffractive phenomena (together with CMS) with high cross-sections • Measurement of leading particles • Particle and energy flow in the forward direction • Different running scenarios • b* = 1540, 90, 18, 0.5 m See my plenary talk TOTEM TDR is fully approved by the LHCC and the Research Board Concentrate on these DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  3. +TOTEM DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  4. TOTEM Experiment (symmetric about IP5) RP T1 & T2 RP DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  5. TOTEM + CMS Experimental Apparatus T1:3.1 < h < 4.7 T2: 5.3 <h< 6.5 10.5 m T1 ~14 m T2 CASTOR (CMS) pairs 4m apart RP1 (147 m) RP2 (180 m) (later option) RP3 (220 m) DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  6. ~3 m T1 Telescope 3.1< |h| <4.7 • 5 planes with measurement of three coordinates per plane. • 3 degrees rotation and overlap between adjacent planes • Primary vertex reconstruction • Trigger with CSC wires 1 arm DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  7. T2 Telescope 5.3< lhl < 6.5 GEM (Gas Electron Multiplier) Telescope: 10 ½-planes 13.5 m from IP Digital r/o pads Analog r/o circular strips 40 cm DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  8. TOTEM ROMAN POT IN CERN SPS BEAM DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  9. reconstructed track Tracks BPM 0 Roman Pots Test beam data: reconstructed tracks in y u,v info RP in SPS beam and the detector is measuring the halo Roman Pot unit: - Measurement of very small p scattering angles (few mrad) - Vertical and horizontal pots mounted as close as possible - BPM fixed to the structure gives precise position of the beam - TOTEM at the RP: sbeam ≈ 80 mm - Leading proton detection at distances down to 10sbeam + d - Need “edgeless” detectors that are efficient up to the physical edge to minimize “d” DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  10. Active edges: X-ray measurement Add here photo of RP Signal [a.u.] 5mm deadarea 150 mm Strip 1 Strip 2 Detector 1 Detector 2 Edgeless silicon detectors for the RP 10 planes/pot Planar technology: Testbeam 40 m dead area 66 mm pitch 10 mm dead area 50 mm dead area active edges (“planar/3D”) planar technology CTS (Curr. Termin. Struct.) DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  11. TOTEM Optics conditions LTOTEM~ 1028-29 cm-2 s –1 TOTEM needs special/independent short runs at high-b* (1540m) and low e Scattering angles of a few mrad High-b optics for precise meas.t of the scattering angles(q*) = e / b* ~ 0.3 mrad As a consequencelarge beam sizes* = e b* ~ 0.4 mm Reduced number of bunches (43 and 156) to avoid interactions downstream New optics b*= 90 m To optimize diffractive proton detection at L=1030-31 in the “warm” region at 220m |tmin| = 3 x 10-2 GeV2 x determination with a precision of few 10-4 ~ 65% of all diffractive protons are seen Status: • easier than higher b* (which needs special injection) • can be obtained by un-squeezing from 18 m injection optics • TOTEM needs to estimate their accuracy of stot (~5%??) DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  12. Running Scenarios For b* = 0.5 m, See M. Ruspa’s talk DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  13. pp total cross section pp total Cross-Section Luminosity-independent measurement using the Optical Theorem: • Measure the total rate (Nel+Ninel) , sdiff ~ 18 mb and min. bias ~65 mb, with an expected precision of 0.8 % (running for 1 day at L = 1.6 x 1028cm-2s-1). • Extrapolate the elastic cross-section to t = 0: systematics dominated: 0.5 % (statistical error after 1 day: 0.07 %) • ρ =Re f(0)/Im f(0) unknown; using COMPETE pred.: 0.2 % 1 % (r= 0.1361±0.0015+0.0058-0.0025) DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  14. pp total Cross-Section • Current models predictions: 90-130 mb • Aim of TOTEM: ~1% accuracy (~1 mb) E811-CDF disagreement ≈ 2.6s (~10 mb) COMPETE Collaboration fits all available hadronic data and predicts: LHC: DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006 [PRL 89 201801 (2002)] Cudell et al.

  15. Elastic scattering – from ISR to Tevatron ~1.5 GeV2 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  16. Photon - Pomeron interference  r Multigluon (“Pomeron”) exchange  e– B |t| ds/dt [mb / GeV2]  t  p2q2 diffractive structure pQCD wide range of predictions pp 14 TeV BSW model -t [GeV2] ~1 day (1) (3) pp elastic scattering cross-section 104 per bin of 10-3 GeV2 B(s) = B0 + 2aP’ ln (s/s0) ~ 20 GeV-2 at LHC tmin from 1.3 mm = 10s+0.5mm at 220m RP ~ 1/|t|8 BSW = Bourrely, Soffer and Wu b*=18 m L = 3.6 x 1032 cm-2 s-1 (3) b* = 1540 m L = 1.6 x 1028 cm-2 s-1 (1) DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  17. Elastic Scattering Models (eg. Islam et al) • Observations: • fwd diffraction cross section increases • diffractive peak shrinks • interference dip moves to smaller t • at –t  1 GeV2: • ds/dt  1/t8 • (3-gluon exchange) • little s dependence  1/t8 Islam et al BSW Desgrolard et al DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  18. Elastic Scattering- el/tot Rdiff=[sel(s) +sSD(s) + sDD(s)]/stot(s) Rel = sel(s)/stot(s) 0.3 0.30 0.4 0.375 0.2 0.3 0.1 0.2 4 5 6 3 4 6 3 5 log(s/s0) • sel  30% of stot at the LHC ? • sSD + sDD  10% of stot (= 100-150mb) at the LHC ? DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  19. T1,T2 T1,T2 Roman Pots Roman Pots TOTEM+CMS CMS + TOTEM: Acceptance largest acceptance detector ever built at a hadron collider 90% (65%) of all diffractive protons are detected forb* = 1540 (90) m 107 min bias events, incl. all diffractive processes, in 1 day with b* =1540 m Total TOTEM/CMS acceptance Charged particles b*=90m dNch/dh ZDC RPs CMS central T1 HCal T2 CASTOR Energy flux dE/dh b*=1540m Pseudorapidity: = ln tg /2 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  20. Diffraction at b* = 1540 m Acceptance RP at 220 m kinematically excluded • Diffractive protons are observed in a large x-t range: • x=Dp/p; t=-(pq)2 • 90% are detected • -t > 2.5x10-3 GeV2 • 10-8 < x < 0.1 • x resolution ~5x10-3 acc. < 10% DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  21. Diffraction at b* = 90 m Acceptance Resolution in x: s(x) = 4x10-4 (prel.) L<2x1030 cm-2s-1 65% of all diffractive protons are detected DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  22. TOTEM+CMS Physics: Soft Diffractive Event rates (limited by DAQ to ~1 kHz) See next Scenario: (1) (2) b* = 1540 m DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  23. hard M u jet 1 (pT 1) p d jet 2 (pT 2) u jet 3 (pT 3) hard g g p p hard Double Pomeron Exchange M Hard Diffractive Events Diffractive events with high pT particles produced for b*=90 m and preliminary • Double diffraction: • pp  p jj Xp • = 1 mb pT > 10 GeV • Acc = 29.3% • Excl: s = 7 nb • pp  p jj p DPE: pp  pXp s = 1 mb Acc = 27.8% Single diffraction: pp  p + 3j DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  24. diffractive system X proton:p1’ proton:p2’ rapidity gap rapidity gap hmin hmax Particle production in Double Pomeron Exchange Use the LHC as a clean gluon-gluon collider Exchange of colour singlets (“Pomerons”)  rapidity gaps Dh Most cases: leading proton(s) with momentum loss Dp / px (typically x< 0.1) MX2 = x1 x2 s Dh2= – ln x2 Dh1= – ln x1 Quantum numbers are defined for exclusive particle production Gluonic states c , b , Higgs, supersymmetric Higgs,….. See M. Ruspa/ B. Cox talks DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  25. p1’ p1 Events / GeV day 10-1 2x106 107 P [Pomeron trajectory a(t) = 1 + e + a’ t ] 10-2 2x105 106 dsDPE / dMX [mb / GeV] p2 p2’ 10-3 2x104 105 10-4 2000 104 10-5 200 103 10-6 20 102 200 MX [GeV] L = 2x1029, 1030 cm-2s-1 TOTEM + CMSDiffractive Physics: DPE X Measure > 90% of leading protons with RPs and diffractive system ‘X’ with T1, T2 and CMS. -Threshold scan for New Physics -Triggered by leading proton and seen in CMS -Central production of states X: X = cc, cb, Higgs, dijets, SUSY particles, ... Scenario (2) (4) b* (m) = 1540 90 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  26. Exclusive Production by DPE: examples Advantage: Selection rules: JP = 0+, 2+, 4+; C = +1  reduced background, determination of quantum numbers. Good f resolution in TOTEM: determine parity: P = (-1)J+1 ds/df ~ 1 +– cos 2f LHC (CMS+TOTEM): • Higgs needs L ~ 1033 cm-2 s-1, i.e. a running scenario forb*= 0.5 m: • trigger problems in the presence of overlapping events • install additional Roman Pots in cold LHC region (420 m) at a later stage See B. Cox’s talk DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  27. Measure total cross-section stot with a precision of1% L = ~1028 cm-2 s-1 with b* = 1540 m Measure elastic scattering in the range10-3 < |t| < 8 GeV2 L = ~1032 cm-2 s-1 with b* = 18 m → high |t| L = ~1028 cm-2 s-1 with b* = 1540 m → low |t| A study of soft diffraction and forward physics: With b* = 1540 m optics at L = 21029 cm-2 s-1 : semi-hard diffraction (pT > 10 GeV) ~ 2x107single and double diffractive events/day ~ 106double Pomeron events/day With b* = 90 m optics (still under study) at L~ 2x1030 cm-2 s-1: hard diffraction and DPE ~ 107double Pomeron events/day Status: Test beam (“TOTEMino”) in Fall 2006 for RP, T1 and T2 TOTEM and CMS are writing a TDR for common diffractive physics Summary DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  28. Extra slides DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

  29. T2 Telescope DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/2006

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