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The experiment

The experiment. at the LHC. Prime Misure Attivita ` di Pisa/Siena Composizione Gruppo Richieste 2012 Stefano Lami on behalf of the TOTEM PISA/SIENA Group. RP. T1. T2. T1: 3.1 < | h | < 4.7 T2: 5.3 < | h | < 6.5. 147. 220.

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The experiment

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  1. The experiment at the LHC • Prime Misure • Attivita` di Pisa/Siena • ComposizioneGruppo • Richieste 2012 • Stefano Lami • on behalf of the • TOTEM PISA/SIENA Group

  2. RP T1 T2 T1: 3.1 < |h| < 4.7 T2: 5.3 < |h| < 6.5 147 220 Stefano Lami

  3. T2 Installato e operativo T1 installatoshutdown 2010/11 e operativo RP 147 /220 installate e operative T1: 3.1 < |h| < 4.7 T2: 5.3 < |h| < 6.5 147 220 Stefano Lami

  4. T1 TOTEM complete and operational for 2011/12 dedicated runs

  5. Scattering Elastico 2010: tracceprotonenelle RP220in diagonale(coincidenze left-right) t = -p2q2 Sector 56 x = Dp/p y = LyQy x = LxQx + xD Lx ~ 0 Sector 45

  6. Selezioneeventi • Topology • near and far units • diagonals • Low || selection (3σ) • |xRP,45|<3σx @Lx,45=0 • |xRP,56|<3σx @Lx,56=0 • corr. yRP216,45  yRP220,45 • corr. yRP216,56 yRP220,56 • Elastic collinearity (3σ) • θx,45* θx,56* • θy,45* θy,56* Integrated luminosity : 6.2 nb-1

  7. Collinearita` background signal background signal Data outside the 3σ cuts used for background estimate

  8. Distribuzione finale |Systematic normalisation uncertainty30%

  9. Elastic Scattering – from ISR to Tevatron ISR ~ 1.7 GeV2 Tevatron ~ 0.7 GeV2 ~1.5 GeV2

  10. Comparison to somemodels Better statistics at large t needed

  11. Future analyses of existing data RP – 18 s2010 data (5.8 pb-1) – Double Pomeron Exchange, RP +T1 and T2 (2011 data from 6 low L pilots) 2. Inelastic detectors T1 and T2 (data from 2011) – Pseudorapidity distributions (including RP information) – Multiplicity distributions and correlations Future runs 2011 • RP 220 m fully validated (14 s vert., 17 s horiz. in normal runs):large-t elastic scattering, β*=1.5 m • RP 147 m beam based alignment with data taking (August):diffraction • β* = 90 m optics • – First MD (done): successful for separated beams • – Next MD (28. June): establish collisions and ~1hour data taking for opticsdiagnostics • – Physics starting in August /September • Low-t (10 -2 GeV2) elastic scattering • Total cross-section (extrapolation to t=0 possible)

  12. Contributo TOTEM Pisa/Siena Progetto e realizzazione Elettronica T2 Responsabilita` Trigger L1 Ricerca e sviluppo tecnologia dei rivelatori Installazione e messa a punto T2 Sviluppo Algoritmi di Ricostruzione

  13. Commissioning, allineamento, analisidatidi T2 2011 Raw data Very good agreement: - left and right side - bunch and active trigger Pythia PhoJet Unfolded Green band after vertex cuts Low luminosity runs 2010 ‘Plus’ and ‘minus’ T2 sides superimposed - Bunch crossing trigger - T2 detector trigger Taken during scraping exercise only low intensity bunches of 1010 p (low pile-up)

  14. Richieste INFN per servizi locali • Nessuna richiesta per Officina Meccanica • Minimo supporto per manutenzione Elettronica sviluppata a Pisa/Siena, update Firmware. • Laboratorio Alte Tecnologie: • Possibile bondaggio dei rimanenti ibridi, ~ 1 settimana lavoro.

  15. ComposizioneGruppo 9.2 FTE (in linea con gli anni scorsi)

  16. Preventivodispesa 2012

  17. Backup Stefano Lami

  18. Preliminary dN/dh results (T1) • 3 short periods of data taking with useful conditions for T1(L = 1028 – 1030 cm–2 s–1): March (2.76 TeV), May (7 TeV) • 25 million events collected with different configurations • Data analysis in progress • T1 ready for physics h Distributions (uncorrected) Vertexreconstruction 7 TeV Vertex reconstruction is effected by the CMS magnetic field Symmetric distributions obtained – a good starting point

  19. Proton reconstruction • Both angle projections reconstructed: Θx* and Θy* • Θx* from Θx @ RP220 (through dLx/ds) Θx = dLx/ds Θx* • Θy* from y @ RP220 (through Ly) y = Ly Θy* • → Excellent optics understanding • Magnet currents measured • Measurements of optics parameters with elastic scatt. • Θleft* = Θright* (proton pair collinearity) • Proton position↔angle correlations • Lx=0 determination, coupling corrections • → Fine alignment • Alignment between pots with overlapping tracks (1μm) • Alignment with respect to the beam – scraping exercise (20μm) • Mechanical constraints between top and bottom pots (10μm) Track based alignment

  20. Background and resolution determination –– signal –– backgrnd –– combined B/S =(8±1)% σ*=17.8rad (beam divergence) Data Combined background (t) -t [GeV2] θx/sqrt(2) Signal to background normalisation Signal vs. background (t) (also as a function of θy) σ* → t-reconstruction resolution: |t|=0.4GeV2: B/S = (11±2)% |t|=0.5GeV2: B/S = (19±3)% |t|=1.5GeV2: B/S = (0.8±0.3)%

  21. ty-acceptancecorrections |t|<0.36GeV2 removed |ty| (diagonal 1) Beam divergence |ty| (diagonal 2) Missing acceptance inθy* Correction error (ty): 0.31 GeV2 : 30% 0.33 GeV2 : 11% 0.35 GeV2 : 2% 0.4 GeV2 : 0.8% 0.5 GeV2 : 0.1%

  22. -acceptance correction Total -acceptance correction Accepted (t) Diagonal 1 1 2 3 4 5 6 Θ*  |t|<0.36GeV2 removed Diagonal 2 Accepted (t) Critical at low t-acceptance limit

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