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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ 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 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 TOTEM Collaboration

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ TOTEM TDR is fully approved by the LHCC and the Research Board TOTEM Physics Total cross-section tot with a precision of 1% Elastic pp scattering in the range: < |t| = (p ) 2 < 10 GeV 2 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 * = 1540, 90, 18, 0.5 m See my plenary talk Concentrate on these

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ TOTEM

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ TOTEM Experiment (symmetric about IP5) T1 & T2 RP

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ T1: 3.1 < < 4.7 T2: 5.3 < < 6.5 T1 T2 CASTOR (CMS) RP1 (147 m) RP2 (180 m) (later option) RP3 (220 m) Experimental Apparatus 10.5 m ~14 m TOTEM + CMS pairs 4m apart

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ planes with measurement of three coordinates per plane. 3 degrees rotation and overlap between adjacent planes Primary vertex reconstruction Trigger with CSC wires T1 Telescope 3.1< | | <4.7 ~3 m 1 arm

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ < l l < 6.5 GEM (Gas Electron Multiplier) Telescope: 10 ½ -planes 13.5 m from IP T2 Telescope Digital r/o pads Analog r/o circular strips 40 cm

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ TOTEM ROMAN POT IN CERN SPS BEAM

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Roman Pot unit: - Measurement of very small p scattering angles (few rad) - Vertical and horizontal pots mounted as close as possible - BPM fixed to the structure gives precise position of the beam - TOTEM at the RP: beam ≈ 80 m - Leading proton detection at distances down to 10 beam + d - Need “edgeless” detectors that are efficient up to the physical edge to minimize “d” 0 reconstructed track Tracks Roman Pots Test beam data: RP in SPS beam and the detector is measuring the halo u,v info reconstructed tracks in y BPM

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Planar technology: Testbeam 40 m dead area Detector 1 Detector 2 active edges (“planar/3D”) planar technology CTS (Curr. Termin. Struct.) 50 m dead area10 m dead area 66 m pitch Add here photo of RP Active edges: X-ray measurement m Signal [a.u.] 5 m dead area Strip 1 Strip 2 Edgeless silicon detectors for the RP 10 planes/pot

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ High- optics for precise meas.t of the scattering angle * ) = / * ~ 0.3 rad As a consequence large beam size * = * ~ 0.4 mm Reduced number of bunches (43 and 156) to avoid interactions downstream L TOTEM ~ cm -2 s –1 TOTEM needs special/independent short runs at high- * 1540m and low Scattering angles of a few rad TOTEM Optics conditions To optimize diffractive proton detection at L= in the “warm” region at 220m |t min | = 3 x GeV 2 ~ 65% of all diffractive protons are seen determination with a precision of few New optics *= 90 m Status: easier than higher * (which needs special injection) can be obtained by un-squeezing from 18 m injection optics TOTEM needs to estimate their accuracy of tot (~5%??)

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Scenario Physics: 1 low |t| elastic, tot, min. bias, soft diffraction 2 diffraction 3 large |t| elastic 4 hard diffraction large |t| elastic (under study) * [m] N of bunches N of part. per bunch (x10 11 ) Half crossing angle [ rad] Transv. norm. emitt. [ m rad] RMS beam size at IP [ m] RMS beam diverg. [ rad] Peak luminosity [cm -2 s -1 ]1.6 x x x x Running Scenarios For * = 0.5 m, See M. Ruspa’s talk

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ pp total Cross-Section Measure the total rate (N el +N inel ), diff ~ 18 mb and min. bias ~65 mb, with an expected precision of 0.8 % (running for 1 day at L = 1.6 x cm -2 s -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 % ( = ± ) pp total cross section Luminosity-independent measurement using the Optical Theorem :

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Current models predictions: mb Aim of TOTEM: ~1% accuracy (~1 mb) LHC: COMPETE Collaboration fits all available hadronic data and predicts: [PRL (2002)] Cudell et al. pp total Cross-Section E811-CDF disagreement ≈ 2.6 mb

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ ~1.5 GeV 2 Elastic scattering – from ISR to Tevatron

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ * = 1540 m L = 1.6 x cm -2 s -1 (1) 10 4 per bin of GeV 2 diffractive structure Photon - Pomeron interference pQCD pp 14 TeV BSW model Multigluon (“Pomeron”) exchange e – B |t| -t [GeV 2 ] t p 2 2 d /dt [mb / GeV 2 ] ~1 day (1) (3) wide range of predictions pp elastic scattering cross-section * =18 m L = 3.6 x cm -2 s -1 (3) ~ 1/|t| 8 t min from 1.3 mm = 10 +0.5mm at 220m RP BSW = Bourrely, Soffer and Wu B(s) = B P ’ ln (s/s 0 ) ~ 20 GeV -2 at LHC

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Observations: fwd diffraction cross section increases diffractive peak shrinks interference dip moves to smaller t at –t 1 GeV 2: d /dt 1/t 8 (3-gluon exchange) little s dependence Elastic Scattering Models (eg. Islam et al) 1/t 8 BSW Desgrolard et al Islam et al

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ R el = el (s)/ tot (s) R diff =[ el (s) + SD (s) + DD (s)] / tot (s) 0.30 el 30% of tot at the LHC ? SD + DD 10% of tot (= mb) at the LHC ? Elastic Scattering- el / tot log(s/s 0 )

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ % (65%) of all diffractive protons are detected for * = 1540 (90) m largest acceptance detector ever built at a hadron collider Roman Pots TOTEM+CMS T1,T2 Roman Pots dN ch /d dE/d Total TOTEM/CMS acceptance CMS central T1 HCal T2 CASTOR =90m RPs =1540m ZDC Pseudorapidity: = ln tg /2 Energy flux Charged particles CMS + TOTEM: Acceptance 10 7 min bias events, incl. all diffractive processes, in 1 day with * =1540 m

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Diffraction at * = 1540 m Acceptance Diffractive protons are observed in a large -t range: = p/p; t=-(p ) 2 90% are detected -t > 2.5x10 -3 GeV 2 < < 0.1 resolution ~5x10 -3 kinematically excluded RP at 220 m acc. < 10%

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Diffraction at * = 90 m Acceptance Resolution in : = 4x10 -4 (prel.) L<2x10 30 cm -2 s -1 65% of all diffractive protons are detected

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

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Hard Diffractive Events Diffractive events with high p T particles produced M M hard Double Pomeron Exchange hard p p jet 1 (p T 1 ) jet 2 (p T 2 ) jet 3 (p T 3 ) p gg u d u Single diffraction: pp p + 3j Double diffraction: pp p jj Xp = 1 b p T > 10 GeV Acc = 29.3% Excl: = 7 nb pp p jj p DPE: pp pXp = 1 mb Acc = 27.8% for *=90 m and preliminary

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Particle production in Double Pomeron Exchange Quantum numbers are defined for exclusive particle production Gluonic states c, b, Higgs, supersymmetric Higgs,….. Use the LHC as a clean gluon-gluon collider Exchange of colour singlets (“Pomerons”) rapidity gaps Most cases: leading proton(s) with momentum loss p / p (typically < 0.1) diffractive system X proton:p 2 ’ proton:p 1 ’ rapidity gap min max 2 = – ln 1 = – ln M X 2 = s See M. Ruspa/ B. Cox talks

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Measure > 90% of leading protons with RPs and diffractive system ‘X’ with T1, T2 and CMS. TOTEM + CMS Diffractive Physics: DPE -Threshold scan for New Physics -Triggered by leading proton and seen in CMS -Central production of states X: X = c, b, Higgs, dijets, SUSY particles,... p1p1 p2p2 p2’p2’ p1’p1’ P X Scenario (2) (4) * (m) = x x x Events / GeV day L = 2x10 29, cm -2 s M X [GeV] d DPE / dM X [mb / GeV] [Pomeron trajectory (t) = 1 + + ’ t ]

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Advantage: Selection rules: J P = 0 +, 2 +, 4 + ; C = +1 reduced background, determination of quantum numbers. Good resolution in TOTEM: determine parity: P = (-1) J+1 d /d ~ 1 +– cos 2 Higgs needs L ~ cm -2 s -1, i.e. a running scenario for = 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 Exclusive Production by DPE: examples LHC (CMS+TOTEM): See B. Cox’s talk

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Measure total cross-section tot with a precision of 1% L = ~10 28 cm -2 s -1 with * = 1540 m Measure elastic scattering in the range < |t| < 8 GeV 2 L = ~10 32 cm -2 s -1 with * = 18 m → high |t| L = ~10 28 cm -2 s -1 with * = 1540 m → low |t| A study of soft diffraction and forward physics: With * = 1540 m optics at L = 2 cm -2 s -1 : semi-hard diffraction (p T > 10 GeV) ~ 2x10 7 single and double diffractive events/day ~ 10 6 double Pomeron events/day With * = 90 m optics (still under study) at L ~ 2x10 30 cm -2 s -1 : hard diffraction and DPE ~ 10 7 double 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

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ Extra slides

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April 22, 2006 DIS2006 XIV International Workshop on Deep Inelastic Scattering Tsukuba, Japan, 20-24/April/ T2 Telescope

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