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LHC b COMMISSIONING and operation

Dirk Wiedner- On behalf of the LHCb Collaboration. LHC b COMMISSIONING and operation. Physics at the LHC 2010. LHCb Commissioning . CALORIMETERS. Trackers. VErtex LOcator. MAGNET. MUON Detector. RICHes. Outline. HARDWARE installation. The LHCb Experiment Commissioning before Beam

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LHC b COMMISSIONING and operation

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  1. Dirk Wiedner- On behalf of the LHCb Collaboration LHCb COMMISSIONINGand operation Physics at the LHC 2010

  2. LHCb Commissioning CALORIMETERS Trackers VErtex LOcator MAGNET MUON Detector RICHes Outline HARDWARE installation • The LHCb Experiment • Commissioning before Beam • pp collisions 2009/10 • Conclusions TRACKER detectors Dirk Wiedner on behalf of LHCb

  3. LHCb Detector pp Collision December 2009 BEAM2 BEAM1 [zy] [zx] Muon Calorimeters (ECAL, HCAL) MAGNET 4 Tm RICH2 Tracker (IT,OT) Acceptance: 15‐250 mrad (V) 15‐300 mrad (H)  1.9 < η < 4.9 Vertex (VELO) RICH1 p p Tracker Turicensis (TT) p p Dirk Wiedner on behalf of LHCb

  4. B+ J/Ψ K+ Dirk Wiedner on behalf of LHCb

  5. Trigger Strategy L0 (up to 1 MHz) Muon trigger Calorimeter trigger (electron, photon, hadron) HLT: computer-farm running full reconstruction L0 confirmation and vertexing Up to 2 kHz output Dirk Wiedner on behalf of LHCb

  6. Detector Calibration: Commissioning Steps WITHOUT Beam Test pulse (LED, pulsing systems and radioactive source) Calorimeters time aligned ~ 1ns Each Muon half-station internally aligned ~ 3 ns No relative time alignment between different sub-detectors Commissioning with Cosmics (started spring 2008) Detector acceptance and trigger optimized with respect to the interaction point ~ 4 M events collected Sub-detector relative time alignment WITH Beam LHC injection test (started September 2008) TED Runs: Beam2 dumped on the injection line beam stopper 350 m downstream LHCb Particles coming from behind the detector and not centered (8 mrad [H] and 12 mrad [V]) Time alignment between sub-detectors ~1 ns Spatial alignment Beam-gas interactions WITH Collisions 450 GeV fills (2009) 3.5 TeV fills (2010) 2008 cosmics data OUTER TRACKER MUON CALORIMETERS Dirk Wiedner on behalf of LHCb

  7. Proton-proton collisions Dirk Wiedner on behalf of LHCb

  8. Velo Velo sensors all powered With 450 GeV beams we could not fully close the Velo . . . but we see where the beams are Dirk Wiedner on behalf of LHCb

  9. Velo Velo closed for the first time on 1. April Closing procedure now takes routinely < 15 minutes Stability in (X; Y ; Z) : (10; 4; 10) μm PV resolution for track multiplicity of 25 x: ~16 μm y: ~15 μm z: ~90 μm Dirk Wiedner on behalf of LHCb

  10. Silicon trackers TT and IT fully operational Signal to noise ratio as expected Alignment ongoing Residual width is 65μm See Tracking and alignment in LHCb by Florin MACIUC Dirk Wiedner on behalf of LHCb

  11. Outer tracker Outer tracker Drift tubes with TDC Fully operational Time and space alignment on a good track Resolution 276 μm Drift-time space relation determined Dirk Wiedner on behalf of LHCb

  12. Tracking  Λ ~65  μb-1 See Tracking and alignment in LHCb by Florin MACIUC • The masses of the reconstructed Λ in agreement with the PDG values • Tracking without VELO: tracking detectors were well calibrated at the start-up ! • Now using full tracking power, including VELO • Tracking in good shape for charm and beauty physics M(Λ) = 1115.74 ± 0.01 MeV/c2 σ = 2.83 ± 0.15MeV/c2 M(ΛPDG) =1115.68 MeV/c2 Dirk Wiedner on behalf of LHCb

  13. RICHes ~65  mμb-1 Preliminary RICH1 See LHCb particle ID by Philip XING Kaon ring Preliminary RICH2 Kaon ring With RICHes PID! Beam-Beam December 2009 • RICH (Ring Imaging CHerenkov) • allow K-π identification from ~ 2 to 100 GeV • Particle IDentification with RICHes • orange points: photon hits • Continuous lines: expected distribution for each particle hypothesis Dirk Wiedner on behalf of LHCb

  14. Calorimeter • The calorimeters systems work very effectively, providing the principal trigger at LHCb • Time alignment now 1 ns • PS/SPD calibration using MIPs • ECAL Energy calibration ongoing. Need 50M events to achieve 1% with π0 • <m> = (135.16 ± 0.02) MeV/c2agreement with the PDG value • σ= (6.06 ± 0.03) MeV/c2 • π0 can be routinely monitored on-line π0 Dirk Wiedner on behalf of LHCb

  15. Muon CALORIMETERs TRACKERs Beam-Beam @ 3.5 TeV 2010 See J/Psi results from LHCb by Julien COGAN Results and prospects for dimuon final states at LHCb by Justine SERRANO • Muon system works very well • part of L0 trigger • Event with dimuons • Oppositely charged muon candidates from the interaction region • Time resolution in perfect agreement with expectation! • J/Ψ peak from dimuon events • 12.8 nbarn -1 of data MUON J/Ψ Dirk Wiedner on behalf of LHCb

  16. LHC/LHCb operation procedure Fill sequence for physics fill in LHCb: NO_BEAM INJECTION RAMP PHYS_ADJUST Velo open PHYSICS Velo closed DUMP Velo open End Of Fill Dirk Wiedner on behalf of LHCb

  17. LHC/LHCb operation procedure LHC State LHCb State Handshake HV/LV State VELO Motion Control Coming to a screen near you! Fill sequence for physics fill in LHCb: NO_BEAM INJECTION RAMP PHYS_ADJUST PHYSICS DUMP End Of Fill Dirk Wiedner on behalf of LHCb

  18. Detector and Run Control LHCb PVSS Global Console • Run the LHCb detector as a whole from one console • All sub-detectors included and operational • Detector readout with HLT1 selection • Data storage at nominal 2 kHz • Detector operated with a unified control software • PVSS to control HW and SW processes LHCb Control Room Dirk Wiedner on behalf of LHCb

  19. Data Quality Data manager Alarms and errors Channel maps Online reconstruction Trigger control plots Problem data base Data quality shift Express stream Reconstruction Data quality group Stripping of all physics runs Categorization of runs Ks Dirk Wiedner on behalf of LHCb

  20. Luminosity So far 14 nbarn-1 Luminosity will be measured at LHCb with beam gas LHCb (In-) Efficiency Dirk Wiedner on behalf of LHCb

  21. Conclusions • LHCb detector is in good shape! • Cosmics data have been very useful for the commissioning of LHCb detector • First collisions were used to conclude commissioning • higher statistics are now used to fine tune calibrations • Intense physics program to fulfill (integrated luminosity ~1 fb-1 in 12-18 months) with many channels to look at… • J/y from D or B • mixing measurements in the D sector • search for CPV • Bs m m ; fs from Bs J/y f • rare decays (D0mm) in the charm sector • And more: CKM-γ, … • See also: • Status of and news from LHCb by Andrei GOLUTVIN (Imperial College) • Tracking and alignment in LHCb by Florin MACIUC • LHCb particle ID by Philip XING • LHCb first physics results by Olivier SCHNEIDER • Minimum bias physics at LHCb by Walter BONIVENTO • Charm physics results and prospects at LHCb by Joerg MARKS • J/Psi results from LHCb by Julien COGAN • Results and prospects for dimuon final states at LHCb by Justine SERRANO • Prospects for CP violation at LHCb by Geraldine CONTI 730 members 15 countries 54 institutes LHCb collaboration Dirk Wiedner on behalf of LHCb

  22. Thanks! 730 members 15 countries 54 institutes LHCb collaboration Dirk Wiedner on behalf of LHCb

  23. Backup Dirk Wiedner on behalf of LHCb

  24. Trigger • Level0 hardware trigger 40 MHz  1 MHz • ~ 12 MHz visible interaction @ 2•1032 cm-2s-1 • Search for high pT and ET candidates • e, γ, μ, hadron • Pile‐up veto • High Level Trigger 1 MHz  2 kHz • Software trigger • HLT1 1MHz  30 kHz • Confirms Level0 candidates • Vertex and tracker detectors • Impact parameter and lifetime cuts • HLT2 30 kHz  2kHz • Full detector information • Inclusive and exclusive selection Dirk Wiedner on behalf of LHCb

  25. LHCb Experiment bb-bar production along the beam axis • Single-arm forward spectrometer dedicated to study b physics • bb-bar pairs produced with a high boost are highly forward or backward • 2009 run conditions(s1/2 = 900 GeV) • Integrated luminosity ~ 7 μb-1 • Expected conditions next run 2010/11(s1/2 = 7 TeV) • Expected integrated luminosity ~1 fb-1 in 12-18 months • Nominal Conditions (s1/2 = 14 TeV; L = 2 1032 cm-2 s-1) • Integrated luminosity: 2 fb­1/107s → ~1012 bb­bar pairs per year • Large b cross section ~500 b, about 0.6% of total Many B, D mesons to study High background rate • Detector requirements • Highly selective trigger • Good particle identification • Good vertex reconstruction b θb _ b θb b _ LHCb Detector b BEAM2 BEAM1 Dirk Wiedner on behalf of LHCb

  26. Commissioning with Cosmics Muon raw hits acquired with the Calorimeter Trigger  Muon and Calorimeter are in time for FORWARD tracks M1 • Dedicated Level0 trigger selection • Muon Trigger • Nominal coincidence of 5 stations  ~ 0 Hz rate • AND of the two last Muon stations  4 Hz rate • Central Muon station alone (M3)  60 Hz rate • Calorimeter Trigger • Higher Voltage to see MIP  ~ 10 Hz rate • No Vertex constraints • Open a time window of several bunch crossing centered on the triggered one • Time Alignment Event (TAE) • Start time alignment between sub-detectors • Start commissioning of basic Level0 trigger building blocks! • Calorimeters and Muon aligned ~ 3 ns for forward tracks • Improvement of Muon Detector internal time alignment • r.m.s time distribution from 9 ns (first cosmics 2008) to ~ 4 ns (last measurement 2010) M2 M3 M4 M5 t (ns) BACKWARD: not aligned FORWARD: Time Aligned!  Dirk Wiedner on behalf of LHCb

  27. TED run: spatial alignment  VELO, Tracker Turicensis, Inner Tracker detectors  start of spatial alignment • Relative Alignment VELO –Tracker Turicensis (TT) • expected uncertainty VELO-TT extrapolation: 300 μm • hit residual observed in TT: 500 μm • offset: 150-300 μm • Inner Tracker (IT) alignment ~ 15μm TT BEAM2 VELO IT Inner Tracker (IT) BEAM2 Single TED shot [mm] Residual for relative Alignment VELO -Tracker Turicensis (TT) Dirk Wiedner on behalf of LHCb

  28. Splash from Beam1 CALORIMETER  Level0 trigger in nominal condition commissioned with BEAM1!!  Acquired 5 consecutive bunch crossing centered on the trigger event • Beam1 on the Target Collimator Tertiary (TCTh) • Beam1: correct direction • Looking for Halo and splash events • Statistics to better align inner regions! OUTER TRAKER BEAM1 MUON September 2008 time + 25ns -50 ns -25 ns 0 ns + 50ns Readout of 5 bunch crossing centered on the trigger event Dirk Wiedner on behalf of LHCb

  29. Beam – Gas interactions FORWARD BACKWARD • Beam-Empty bunch crossing: • ~ 1 M interaction between beam and the residual gas in beam pipe • VErtex LOcator (VELO) reconstructs the interaction beam – gas • Retractable detector halves • open during injection (30 mm per side) • closed in stable beam condition (Ebeam > 2 TeV) BEAM1 - GAS BEAM2 - GAS Beam1-Gas 11/2009: Triggered by Calorimeters OR Muon (rate ~ 5Hz) Beam2-Gas 11/2009: Triggered by VErtex LOcator: backward silicon stations VErtex LOcator 21 stations of Silicon strip detector Dirk Wiedner on behalf of LHCb

  30. Beam – gas interactions BEAM1 BEAM1 BEAM2 BEAM2 Beam - Gas [XZ] Plane; Crossing Angle Blue: beam1 – empty Red: empty - beam2 Green: beam1- beam2 vertex x (mm) • VELO reconstructs the beams crossing angle using beam-gas interactions • Impact of LHCb dipole magnet • beams cross at 2 mrad angle in [xz] plane as expected at the full magnetic field @ 450 GeV z (m) Beam - Gas [YZ] Plane Dirk Wiedner on behalf of LHCb

  31. Commissioning of DAQ chain • FEST (Full Experiment System Test) • Raw-Monte Carlo events injected into the DAQ chain • inject @ 2kHz at the High Level Trigger input (limited by Monte Carlo injection) • generated 100 M minimum bias (14 hours) • Commissioning of: • run control • run HLT; • exercise control/configuration • HLT processing • online reconstruction and monitoring • Histograms relevant to understand problems • data storage; data quality • Procedure to give the green light • interaction with the GRID Injector DAQ network FEST data flow Data Acquisition Boards LHCb detector data flow High Level Trigger Farm ONLINE and OFFLINE data Monitoring and Processing 1.9 kHz achieved steadily Dirk Wiedner on behalf of LHCb

  32. LHCb clock phase LHCb clock to LHC beam phase temperature dependant Seasonal and daily time walk Beam pickup monitor phase measurement Correction if drift >500ps Dirk Wiedner on behalf of LHCb

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