Dirk Wiedner On behalf of the LHCb Collaboration

Dirk Wiedner On behalf of the LHCb Collaboration LHCb COMMISSIONING and operation Physics at the LHC 2010 1

LHCb Commissioning Outline HARDWARE installation CALORIMETERS § The LHCb Experiment § Commissioning before Beam § pp collisions 2009/10 § Conclusions ers k c a r T TRACKE R detect cator LO VErtex MUON ors MAGNET Detect or RICHes 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 2

pp Collision December 2009 BEAM 2 BEAM 1 [zy] LHCb Detector Acceptance: 15‐ 250 mrad (V) 15‐ 300 mrad (H) 1. 9 < η < 4. 9 p MAGNET RICH 2 Tracker 4 Tm Muon [zx] Calorimeters (ECAL, HCAL) (IT, OT) Vertex. RICH 1 (VELO) p Tracker Turicensis p 7 June 2010 p (TT) Dirk Wiedner on behalf of LHCb commissioning and operation 3

B+ J/Ψ K+ 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 4

Trigger Strategy L 0 (up to 1 MHz) Muon trigger Calorimeter trigger (electron, photon, hadron) HLT: computer farm running full reconstruction L 0 confirmation and vertexing Up to 2 k. Hz output 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 5

Detector Calibration: Commissioning Steps WITHOUT Beam 1. 2. Test pulse (LED, pulsing systems and radioactive source) • Calorimeters time aligned ~ 1 ns • Each Muon half station internally aligned ~ 3 ns • No relative time alignment between different subdetectors 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 2008 cosmics data OUTER TRACKER MUON CALORIMETERS WITH Beam 1. LHC injection test (started September 2008) § TED Runs: Beam 2 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 § 2. Spatial alignment Beam-gas interactions WITH Collisions 1. 2. 450 Ge. V fills (2009) 3. 5 Te. V fills (2010) 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 6

Proton proton collisions 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 7

Velo sensors all powered With 450 Ge. V beams we could not fully close the Velo. . . but we see where the beams are 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 8

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 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 9

Silicon trackers See Tracking and alignment in LHCb by Florin MACIUC TT and IT fully operational Signal to noise ratio as expected Alignment ongoing Residual width is 65μm 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 10

Outer tracker Drift tubes with TDC Fully operational Time and space alignment on a good track Resolution 276 μm Drift time space relation determined 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 11

Tracking Λ § § 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 Me. V/c 2 σ = 2. 83 ± 0. 15 Me. V/c 2 M(ΛPDG) =1115. 68 Me. V/c 2 ~65 μb 1 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 12

RICHes See LHCb particle ID by Philip XING RICH 1 Preliminary Kaon ring Preliminary RICH 2 Kaon ring With RICHes PID! Beam-Beam December 2009 ~65 mμb 1 § RICH (Ring Imaging CHerenkov) o allow K π identification from ~ 2 to 100 Ge. V § Particle IDentification with RICHes o orange points: photon hits o Continuous lines: expected distribution for each particle hypothesis 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 13

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 50 M events to achieve 1% with π0 § <m> = (135. 16 ± 0. 02) Me. V/c 2 agreement with the PDG value § σ= (6. 06 ± 0. 03) Me. V/c 2 § π0 can be routinely monitored on line 7 June 2010 Dirk Wiedner on behalf of LHCb π0 LHCb commissioning and operation 14

Muon 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 L 0 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 CALORIMETERs MUON TRACKERs Beam-Beam @ 3. 5 Te. V 2010 § 12. 8 nbarn 1 of data J/Ψ 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 15

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 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 16

LHC/LHCb operation procedure Fill sequence for physics fill in LHCb: NO_BEAM LHC State LHCb State INJECTION RAMP Handshake PHYS_ADJUST HV/LV State VELO Motion Control Coming to a screen near you! PHYSICS DUMP End Of Fill 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 17

Detector and Run Control LHCb PVSS Global Console § Run the LHCb detector as a whole from one console o All sub detectors included and operational o Detector readout with HLT 1 selection o Data storage at nominal 2 k. Hz § Detector operated with a unified control software o PVSS to control HW and SW processes LHCb Control Room 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 18

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 Ks Stripping of all physics runs Categorization of runs 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 19

Luminosity LHCb (In ) Efficiency So far 14 nbarn 1 Luminosity will be measured at LHCb with beam gas 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 20

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… o J/y from D or B o mixing measurements in the D sector o search for CPV o Bs m m ; fs from Bs J/y f o rare decays (D 0 mm) in the charm sector o 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 7 June 2010 Dirk Wiedner on behalf of LHCb 730 members 15 countries 54 institutes LHCb collaboration LHCb commissioning and operation 21

Thanks! 730 members 15 countries 54 institutes LHCb collaboration 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 22

Backup 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 23

Trigger 1. Level 0 hardware trigger 40 MHz 1 MHz o ~ 12 MHz visible interaction @ 2 • 1032 cm 2 s 1 o Search for high p. T and ET candidates • e, γ, μ, hadron o Pile‐up veto 2. High Level Trigger 1 MHz 2 k. Hz o Software trigger o HLT 1 1 MHz 30 k. Hz • Confirms Level 0 candidates • Vertex and tracker detectors • Impact parameter and lifetime cuts o HLT 2 30 k. Hz 2 k. Hz • Full detector information • Inclusive and exclusive selection 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 24

LHCb Experiment § Single arm forward spectrometer dedicated to study b physics bb bar production along the beam axis o bb bar pairs produced with a high boost are highly forward or backward 2009 run conditions (s 1/2 = 900 Ge. V) θb o Integrated luminosity ~ 7 μb 1 b Expected conditions next run 2010/11 (s 1/2 = 7 Te. V) _ o Expected integrated luminosity ~1 fb 1 in 12 18 months b § Nominal Conditions (s 1/2 = 14 Te. V; L = 2 1032 cm 2 s 1) o Integrated luminosity: 2 fb 1/107 s → ~1012 bb bar pairs per year o Large b cross section ~500 � b, about 0. 6% of total LHCb Detector Many B, D mesons to study High background rate 7 June 2010 Dirk Wiedner on behalf of LHCb b _ b 2 M A BE § Detector requirements o Highly selective trigger o Good particle identification θb BE 1 M A LHCb commissioning and operation 25

Commissioning with Cosmics § Dedicated Level 0 trigger selection 1. Muon Trigger Muon raw hits acquired with the Calorimeter Trigger Muon and Calorimeter are in time for FORWARD tracks M 1 • Nominal coincidence of 5 stations ~ 0 Hz rate • AND of the two last Muon stations 4 Hz rate • Central Muon station alone (M 3) 60 Hz rate M 2 2. Calorimeter Trigger • Higher Voltage to see MIP ~ 10 Hz rate M 3 o No Vertex constraints Open a time window of several bunch crossing centered on the triggered one M 4 • Time Alignment Event (TAE) • Start time alignment between sub detectors Start commissioning of basic Level 0 trigger building blocks! o Calorimeters and Muon aligned ~ 3 ns forward tracks Improvement of Muon Detector internal time alignment M 5 BACKWARD: not aligned FORWARD: Time Aligned! t (ns) • r. m. s time distribution from 9 ns (first cosmics 2008) to ~ 4 ns (last measurement 2010) 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 26

TED run: spatial alignment VELO, Tracker Turicensis, Inner Tracker detectors start of spatial alignment § Relative Alignment VELO – Tracker TT Turicensis (TT) BEAM 2 expected uncertainty VELO TT extrapolation: 300 μm o hit residual observed in TT: 500 μm o offset: 150 300 μm o VELO IT § Inner Tracker (IT) alignment ~ 15μm 2 Residual for relative Alignment VELO -Tracker [mm] Turicensis (TT) 7 June 2010 Dirk Wiedner on behalf of LHCb B M EA Inner Tracker (IT) Single TED shot LHCb commissioning and operation 27

Splash from Beam 1 § Beam 1 on the Target Collimator Tertiary (TCTh) CALORIMETER o Beam 1: correct direction OUTER TRAKER § Looking for Halo and splash events Statistics to better align inner regions! M A E B 1 MUON September 2008 Level 0 trigger in nominal condition commissioned with BEAM 1!! Acquired 5 consecutive bunch crossing centered on the trigger event time 50 ns 25 ns 0 ns + 25 ns + 50 ns Readout of 5 bunch crossing centered on the trigger event 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 28

Beam – Gas interactions FORWARD BACKWARD BEAM 1 GAS BEAM 2 - GAS Beam 1 -Gas 11/2009: Triggered by Calorimeters OR Muon (rate ~ 5 Hz) § Beam Empty bunch crossing: Beam 2 -Gas 11/2009: Triggered by VErtex LOcator: backward silicon stations o ~ 1 M interaction between beam and the residual gas in beam pipe § VErtex LOcator (VELO) reconstructs the interaction beam – gas o Retractable detector halves • open during injection (30 mm per side) • closed in stable beam condition (Ebeam > 2 Te. V) 7 June 2010 Dirk Wiedner on behalf of LHCb VErtex LOcator 21 stations of Silicon strip detector LHCb commissioning and operation 29

Beam – gas interactions § VELO reconstructs the beams crossing angle using beam gas interactions § Impact of LHCb dipole magnet o beams cross at 2 mrad angle in [xz] plane as expected at the full magnetic field @ 450 Ge. V BEAM 1 BEAM 2 Beam Gas [XZ] Plane; Crossing Angle 7 June 2010 Dirk Wiedner on behalf of LHCb Blue: beam 1 – empty Red: empty beam 2 Green: beam 1 beam 2 vertex x (mm) z (m) BEAM 1 BEAM 2 Beam Gas [YZ] Plane LHCb commissioning and operation 30

Commissioning of DAQ chain § FEST (Full Experiment System Test) § Raw Monte Carlo events injected into the DAQ chain o inject @ 2 k. Hz at the High Level Trigger input (limited by Monte Carlo injection) o generated 100 M minimum bias (14 hours) § Commissioning of: Injector o run control o HLT processing o online reconstruction and monitoring DAQ network Data Acquisition Boards • Histograms relevant to understand problems o data storage; data quality • Procedure to give the green light • interaction with the GRID LHCb detector data flow FEST data flow • run HLT; • exercise control/configuration High Level Trigger Farm ONLINE and OFFLINE data Monitoring and Processing 1. 9 k. Hz achieved steadily 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 31

LHCb clock phase LHCb clock to LHC beam phase temperature dependant Seasonal and daily time walk Beam pickup monitor phase measurement Correction if drift >500 ps 7 June 2010 Dirk Wiedner on behalf of LHCb commissioning and operation 32