Proton on proton: s = 14 TeVPhysics goals:Detailed study of Standard Model particles: top, b, W, Z, QCD, Electroweak symmetry breaking: Higgs boson(s)Produce Dark Matter (WIMPs)Searches: quark & lepton sub-structure, gravitons, extra dimensions, supersymmetry, The ATLAS experimentat CERNs Large Hadron Collider

ATLAS

Shifting gearStrong history in producing the hardwareSilicon tracker barrel assembled downstairs (see last review talk)Focus strongly shifted to detector commissioning & physics preparationHardware expertise redeployed on tracker upgradeStill part of ATLAS, but see separate SLHC talkMuch of our commissioning effort now at (or visiting) CERNDWB level-3CERN

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ATLASClose to current appearance All major hardware installed

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Semiconductor Tracker4 barrels aroundInteraction point(Oxford assembled)9 disks in each forward direction

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Inner detector:Installation in the cavernSCT+TRT endcap, may 2007 SCT+TRT barrel, August 2006 Barrel had to be fully tested before end-caps could be installed

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SCT: Operational StatusSemiconductor tracker:Barrel and endcaps both connected to electrical and optical services.Functionality checked for all modulesAll but 2 out of 4088 modules are workingNo significant noise increase compared with earlier measurements.Two significant problems needed addressing:Cooling problems in barrelOptical communication with front-end

ATLAS

SCT: Cooling ProblemsSCT cooled down by an evaporative cooling system (C3F8)remove ~40 kW of heatWorking well during SCT barrel tests in the cavern, until...Problem in the heaters:Evaporate the remaining liquid & heat above the cavern dew pointShort in connection to heater element caused heater failureX-ray image of shorted connection First fault in February: The union of a heater blew up after few hours of operation. All non conformities (geometrical and permeability to moisture) found and corrected Another union failed on May 7 while testing Barrel SCT in the pit. This was a golden union, not a single non conformity and was in operation since 5 days.

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SCT: heater solutionHeater position moved to more accessible region (cryostat flange) More robust design (ceramic feedthroughs). New heaters will be installed this autumn (Oxford help with welding). Start analogue measurements of endcap and with cosmic rays

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SCT: Optical LinksSCT front end modules communicate optically with off-detector electronicsclock, trigger, configurations, and hit dataData links: working as expectedControl links: working butbut find low currents in p-i-n diodesome channels marginalSubtle problemcoupling of higher order transverse laser modes to higher order leaky fibre modes

Solution: make new VCSEL arrays with micro-lens arrays to produce more focused beams.Remaining mystery: dont see same scale of problem for EC as for barrel.Weidberg

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FSI: principleMany accurate 1-d measurements of SCT geometryGoal of < 5mm from alignmentFollow fast time-constant changes in detector precision positioningGibson, Nickerson

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FSI: progressOptical cables splicedExpect to complete before end of yearDetectorSplitter designed/built20 9U Mother Boards completed125 Daughter boards completedLight Source tested and moved to CERNControl Electronics - close

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FSI: readoutFSI DAQ has made rapid progress (GV)Read and write to main read-out boardsMake block transfers to diskUsing the ATLAS DAQ system (big advance)Next Steps:Develop online data reductionDirect data to storageIntegrate with conditions dBDevelop final DCS control link

Note that:It was not possible for IT group to supply DAQ expertise anticipatedSignificant, vital, help was given by IT group, but GV had to write the codeThis cant be long term situation in terms of upgrade/maintenanceRequest that long term plan be to allocate DAQ support from IT at 30% fte levelDehchar, Viehhauser

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Oxford rolesContributions to the experiment:Completion of tracker hardware commissioning (including F.S.I.)Tracker operation and precision alignmentPhysics calibrationGrid computing hardware and software

Physics preparationHigh Oxford presence:Standard modelHiggsSupersymmetryHuge Monte Carlo simulation effort in progress:Baseline analysesControl channelsCalibration from dataRunning start for first collisionsSo-called Service work increasingly weighted towards exploitation

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Robust tracking alignment- before - after alignmentIntuitive basic idea:centering overlap residual distributionscenteringresidual distributions For perfectly aligned detector(overlap) residuals should be centered around 0! Correlations between modules are taken into account by iterationsConvergenceResudual mean and RMSReal cosmic-ray dataReal cosmic-ray dataPerformance:beforeafterMonte Carlo SimulationBrandt, Heinemann

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Global 2 algorithmSimultaneous minimisation of track-hit residualsIncludes implicit re-fit of the tracks to take into account all correlationsSolve matrix system with 35,000 DoFUse novel techniques in matrix algebra distributed linear algebra (ScaLapack) fast solver (MA27 with matrix conditioning).3 translations& 3 rotationsof each moduleCosmic Ray Alignment (06)~400k events from of SCT barrel and 1/8 of TRT. No B-field. Before alignment: residuals ~ 65 mm. After alignment: consistent with simulation=54 m=21 mFull-scale simulation 07Unel, Bruckman

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Grid & databasesOxford is developing a prototype Luminosity DatabaseDetector calibration constants, data quality, detector and beam conditionsrelate event-wise data to conditionscompare measured to theoretical rates for Standard Model processesLuminosity dependence / normalization crucialExotic physics identified by excesses above SMBrowser to check database information, study relationships within the dataGallas

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Physics commissioningUnderstanding the detector: using the ATLAS data

Dobson, Fiascaris, Issever, Kirsch, Lohwasser, WeidbergElectron efficiency from ZeeLocal calorimeter compensationMissing-energy resolution: Recoil against Zee

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Standard ModelLimits to theoretical predictions Quark parton distributionsNon-perturbativeAll initial state!Boson + multijetsMeasure in Z+jetsPredict for W+jetsImportant backgrounds to much non-SM physicsCooper-Sarkar, Fiascaris, Gilbert, Issever, Heinemann, Lohwasser

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HiggsOur effort ramping up:h -> WWMedium -> high massesUsing M.E. likelihood techniques from CDFdiscovery within the first two years of LHC collisionsh -> Important at lower massesStudies about to startMissing piece in the Standard Model jigsawThought to break electroweak symmetryGiving particles their masses

Investigating methods for getting backgrounds from data,[Including WW, W, Z]Farrington, Hays, Larner, Wooden

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SupersymmetrySolution to hierarchy problemLightest SUSY particle great candidate for Dark Matter (WIMPs)Twin search strategies:Squarks/GluinosHadronic activity: Jets + Missing energyElectroweak gauginosMultiple lepton signaturesDiscovery top priorityPhenomenology (masses, spins etc) of great theoretical interestOngoing work here Collaboration with Oxford theory & other groupsJets + missing energyMulti- leptonsBarr, Brandt, Bruckman

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ExoticsNew energy regimeLots of possibilitiesIf true Planck scale is of order ~1 TeV:LHC will see strong gravity highly exotic signaturesLarge cross-sections

Multiple W bosons from custodial quark decays Dennis, Issever, Tseng, Unel

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Local Computing NeedsLocal computing critical to obtain results in competitive times5 years plan drawn up, starting mid 2008Based on existing data (ATLAS MC) analysis & experiences at H1, ZEUS and CDFTalked to Ian and Pete: Facilities at Oxford availablePreparing paper for Exec by XmasThe budget required will be ca. 30k/year Hardware will be located in level 1 in DWB.Local computing and disk required for ntuple analysisNB bulk of data selection and reduction will be done on the GRID(already is) This slide shows the additional local requirements

ATLAS

Cast listEager to hit the data:Abdel AbdesselamAlan BarrOleg BrandtPawel BruckmanJames BuchananMandy Cooper-SarkarJonathan Cox MohamedDehchar ChristopherDennisEllie DobsonSinead FarringtonJames FerrandoMariaFiascaris Elizabeth GallasStephen GibsonLaura GilbertChris HaysFlorian HeinemannTodd HuffmanCigdem IsseverGuillaumeKirschAimeeLarner KristinLohwasserCarlyMattravers Richard Nickerson IanPreston Stefan StonjekJeff TsengMuge Unel Georg Viehhauser Tony WeidbergGemma Wooden

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Extras

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WebcamYesterday

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Data-taking

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LHC statusFocusing magnet failure:March 27: There was a serious failure in a high-pressure test at CERN of a Fermilab-built "inner-triplet" series of three quadrupole magnets in the tunnel of the Large Hadron Collider.Sept 28: The repair is now complete thanks to very efficient collaboration. We are all very pleased that we can now put this behind us and focus on getting ready forphysics at the LHC next year.Other potential problems:

ATLAS

Global 2 Alignment Full Scale Tests (CSC) (07)Misalignments introduced to sample of muons (pT: 2-50 GeV) at simulation: Level 1: entire sub-detectors (whole Pixel, SCT)Level 2: silicon layers & disksLevel 3: all silicon modulesLevel 1+2 involves solving small DoFSR1 Cosmic Ray Data Alignment (06)~400k events from of SCT barrel and 1/8 of TRT. No B-field. Before alignment: residuals ~ 65 mm. After alignment: consistent with simulation.Initial misalignments. Track parameters largely distortedAfter L1&L2 (requires solving small nDoF). tracks free of systematic bias After L3, fine resolution of detector recovered

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Analysis ModelCalibration streams studied at CAFData reduction/selection on the GRIDNtuples local farmOptimisation, interactive analysisRun over data for systematics, backgrounds etcSmaller samples of fine-grained data locally for detector-based studies

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-> production version of the Athena code-> understanding of all available constraints on weak modes and an early alignment using pit cosmics