Rusakovich ATLAS Lipnya 2007

Slide1: 

The ATLAS Experiment

Slide2: 

s = 14 TeV (7 times higher than Tevatron)  search for new massive particles up to m ~ 5 TeV Ldesign = 1034 cm-2 s-1 (>102 higher than Tevatron)  search for rare processes with small s (N = Ls ) 27 km ring used for e+e- LEP machine in 1989-2000

Standard Model: 

Standard Model

What is Wrong with the SM ?: 

What is Wrong with the SM ? SM contains too many apparently arbitrary features SM has an unproven element - not some minor detail but a central element - namely mechanism to generate observed masses of the known particles a popular solution is to invoke the Higgs mechanism SM gives nonsense at high energies. At centre of mass energies > 1000 GeV the probability of WW scattering becomes greater than 1! a popular solution is to introduce a Higgs exchange to cancel the bad high energy behaviour SM is logically incomplete - does not incorporate gravity - build TOE is superstring theory the TOE ?

Collisions at the LHC: 

Collisions at the LHC Slide by T. Virdee

Cross Sections and Production Rates: 

Cross Sections and Production Rates Rates for L = 1034 cm-2 s-1: (LHC) LHC is a factory for: top-quarks, b-quarks, W, Z, …. Higgs, …. (The challenge: you have to detect them !) great selectivity needed very powerful detectors needed

Slide7: 

The ATLAS physics goals Search for the Standard Model Higgs boson over ~ 115 < mH < 1000 GeV Search for physics beyond the SM (Supersymmetry, q/ compositeness, leptoquarks, W’/Z’, heavy q/, Extra-dimensions, ….) up to the TeV-range Precise measurements : -- W mass -- top mass, couplings and decay properties -- Higgs mass, spin, couplings (if Higgs found) -- B-physics (complementing LHCb): CP violation, rare decays, B0 oscillations -- QCD jet cross-section and as -- etc. …. Study of phase transition at high density from hadronic matter to plasma of deconfined quarks and gluons (complementing ALICE). Transition plasma  hadronic matter happened in universe ~ 10-5 s after Big Bang Etc. etc. …..

Slide8: 

Already in first year, large statistics expected from: -- known SM processes  understand detector and physics at s = 14 TeV -- several New Physics scenarios Which physics the first year(s) ?

Slide9: 

H  ZZ  4  “Gold-plated” channel for Higgs discovery at LHC Simulation of a H   ee event in ATLAS Physics example

Slide10: 

Supersymmetric particles and dark matter This particle (neutralino) is a good candidate for the universe dark matter Neutralino mass can be measured to 10%  SUSY discovery and neutralino mass measurement at LHC can solve problem of universe cold dark matter

Slide11: 

ATLAS Collaboration (As of the July 2006) 35 Countries 161 Institutions 1650 Scientific Authors total (1300 with a PhD, for M&O share) Albany, Alberta, NIKHEF Amsterdam, Ankara, LAPP Annecy, Argonne NL, Arizona, UT Arlington, Athens, NTU Athens, Baku, IFAE Barcelona, Belgrade, Bergen, Berkeley LBL and UC, Berlin U, Bern, Birmingham, Bologna, Bonn, Boston, Brandeis, Bratislava/SAS Kosice, Brookhaven NL, Buenos Aires, Bucharest, Cambridge, Carleton, Casablanca/Rabat, CERN, Chinese Cluster, Chicago, Clermont-Ferrand, Columbia, NBI Copenhagen, Cosenza, AGH UST Cracow, IFJ PAN Cracow, DESY, Dortmund, TU Dresden, JINR Dubna, Duke, Frascati, Freiburg, Geneva, Genoa, Giessen, Glasgow, LPSC Grenoble, Technion Haifa, Hampton, Harvard, Heidelberg, Hiroshima, Hiroshima IT, Indiana, Innsbruck, Iowa SU, Irvine UC, Istanbul Bogazici, KEK, Kobe, Kyoto, Kyoto UE, Lancaster, UN La Plata, Lecce, Lisbon LIP, Liverpool, Ljubljana, QMW London, RHBNC London, UC London, Lund, UA Madrid, Mainz, Manchester, Mannheim, CPPM Marseille, Massachusetts, MIT, Melbourne, Michigan, Michigan SU, Milano, Minsk NAS, Minsk NCPHEP, Montreal, McGill Montreal, FIAN Moscow, ITEP Moscow, MEPhI Moscow, MSU Moscow, Munich LMU, MPI Munich, Nagasaki IAS, Naples, New Mexico, New York U, Nijmegen, BINP Novosibirsk, Ohio SU, Okayama, Oklahoma, Oklahoma SU, Oregon, LAL Orsay, Osaka, Oslo, Oxford, Paris VI and VII, Pavia, Pennsylvania, Pisa, Pittsburgh, CAS Prague, CU Prague, TU Prague, IHEP Protvino, Ritsumeikan, UFRJ Rio de Janeiro, Rochester, Rome I, Rome II, Rome III, Rutherford Appleton Laboratory, DAPNIA Saclay, Santa Cruz UC, Sheffield, Shinshu, Siegen, Simon Fraser Burnaby, SLAC, Southern Methodist Dallas, NPI Petersburg, Stockholm, KTH Stockholm, Stony Brook, Sydney, AS Taipei, Tbilisi, Tel Aviv, Thessaloniki, Tokyo ICEPP, Tokyo MU, Toronto, TRIUMF, Tsukuba, Tufts, Udine, Uppsala, Urbana UI, Valencia, UBC Vancouver, Victoria, Washington, Weizmann Rehovot, Wisconsin, Wuppertal, Yale, Yerevan

Slide12: 

Diameter 25 m Barrel toroid length 26 m End-cap end-wall chamber span 46 m Overall weight 7000 Tons Construction, integration and installation progress of the ATLAS detector ATLAS superimposed to the 5 floors of building 40

Slide13: 

An Aerial View of Point-1 (Across the street from the CERN main entrance)

Slide14: 

The Underground Cavern at Pit-1 for the ATLAS Detector Length = 55 m Width = 32 m Height = 35 m

Slide15: 

ATLAS Length : ~ 46 m Radius : ~ 12 m Weight : ~ 7000 tons ~ 108 electronic channels ~ 3000 km of cables Tracking (||<2.5, B=2T) : -- Si pixels and strips -- Transition Radiation Detector (e/ separation) Calorimetry (||<5) : -- EM : Pb-LAr -- HAD: Fe/scintillator (central), Cu/W-LAr (fwd) Muon Spectrometer (||<2.7) : air-core toroids with muon chambers

Slide16: 

Central Solenoid 2T field with a stored energy of 38 MJ Integrated design within the barrel LAr cryostat Magnet System The solenoid has been inserted into the LAr cryostat at the end of February 2004, and it was tested at full current (8 kA) during July 2004 It is now cold, and has been successfully tested in situ at a reduced current (awaiting the end-caps for field mapping at full current in August 2006)

Slide17: 

Toroid system Barrel Toroid parameters 25.3 m length 20.1 m outer diameter 8 coils 1.08 GJ stored energy 370 tons cold mass 830 tons weight 4 T on superconductor 56 km Al/NbTi/Cu conductor 20.5 kA nominal current 4.7 K working point End-Cap Toroid parameters 5.0 m axial length 10.7 m outer diameter 2x8 coils 2x0.25 GJ stored energy 2x160 tons cold mass 2x240 tons weight 4 T on superconductor 2x13 km Al/NbTi/Cu conductor 20.5 kA nominal current 4.7 K working point End-Cap Toroid: 8 coils in a common cryostat Barrel Toroid: 8 separate coils

Slide18: 

Barrel Toroid coil transport and lowering into the underground cavern

Slide19: 

The last coil was moved into position on 25th August 2005 The first coil was installed in October 2004 Latest news: the system is being cooled down in situ, and current tests started

Slide20: 

End-Cap Toroids All components are fabricated, and the assembly is now ongoing at CERN The ECTs will be tested at 80 K on the surface, before installation and excitation tests in the cavern The first ECT will move to the pit in October 2006, the second one in early 2007 The first of the two ECT cold masses inserted into the large vacuum vessel

Slide21: 

Inner Detector (ID) The Inner Detector (ID) is organized into four sub-systems: Pixels (0.8 108 channels) Silicon Tracker (SCT) (6 106 channels) Transition Radiation Tracker (TRT) (4 105 channels) Common ID items

Slide22: 

Examples of cosmic ray registered in the barrel TRT in the Inner Detector surface clean room facility SR1 Barrel TRT during insertion of the last modules (February 2005)

Slide23: 

End of February 2006 the barrel SCT was inserted into the barrel TRT, and this component will be ready for the final installation in ATLAS in August 2006 after further commissioning at the surface with cosmics Integrations of the two end-caps (SCT and TRT) are ongoing for installation end of 2006

Slide24: 

Cosmics in the barrel TRT plus SCT

Slide25: 

Inner Detector services (cables and pipes) installation in the inner bore of the barrel cryostat

Slide26: 

LAr and Tile Calorimeters Tile barrel Tile extended barrel LAr forward calorimeter (FCAL) LAr hadronic end-cap (HEC) LAr EM end-cap (EMEC) LAr EM barrel

Slide27: 

LAr EM Barrel Calorimeter Commissioning at the Surface After many years of module constructions, the barrel EM calorimeter was installed in the cryostat, and after insertion of the solenoid, the cold vessel was closed and welded early 2004 A successful complete cold test (with LAr) was made during summer 2004 in hall 180 at CERN (dead channels much below 1%) LAr barrel EM calorimeter after insertion into the cryostat LAr barrel EM calorimeter module at one of the assembly labs

Slide28: 

End of October 2004 the cryostat was transported to the pit, and lowered into the cavern

Slide29: 

The barrel LAr and scintillator tile calorimeters have been since January 2005 in the cavern in their ‘garage position’ (on one side, below the installation shaft) A cosmic ray muon registered in the barrel Tile Calorimeter Barrel LAr and Tile Calorimeters

Slide30: 

November 4th 2005: Calorimeter barrel after its move into the center of the ATLAS detector

Slide31: 

EM beam test results: Energy resolution

Impact on Higgs mass resolution: 

Impact on Higgs mass resolution H   Resolution: 1% (low lum) 1.2% (high lum) Acceptance: 80% within ±1.4  Simulations, mH=130 GeV H  4e Resolution: 1.2% (low lum) 1.4% (high lum) Acceptance: 84% within ±2  H  4 e Mass(GeV) Events

Slide33: 

Muon Spectrometer Instrumentation Precision chambers: - MDTs in the barrel and end-caps - CSCs at large rapidity for the innermost end-cap stations Trigger chambers: - RPCs in the barrel - TGCs in the end-caps The Muon Spectrometer is instrumented with precision chambers and fast trigger chambers A crucial component to reach the required accuracy is the sophisticated alignment measurement and monitoring system

Slide34: 

Barrel MDTs Installation of barrel muon station A major effort is spent in the preparation and testing of the barrel muon stations (MDTs and RPCs for the middle and outer stations) before their installation in-situ The electronics and alignment system fabrications for all MDTs are on schedule

Slide35: 

First cosmics have been registered in situ for barrel chambers In December 2005 in MDTs and in June 2006 in RPCs

Alignment: 

Alignment Need to monitor the movement of the system It is not possible to stabilize to 30mm for a structure of this size The RASNIK system follows movements for correction offline

Slide37: 

Example of tracking the sagitta measurements, following the day-night variation due to thermal variations of chamber and structures, and two forced displacements of the middle chamber

LCG Computing Resources (May 2005, growing!): 

LCG Computing Resources (May 2005, growing!) Number of sites is already at the scale expected for LHC - demonstrates the full complexity of operations

Slide39: 

ATLAS Installation Schedule Version 8.0 - Beam pipe in place end of August 2007 - Restricted access to complete end-wall muon chambers and global commissioning until mid-Oct 2007 - Ready for collisions from mid-October 2007

Slide40: 

Operation Model (Organization for LHC Exploitation) (Details can be found at http://uimon.cern.ch/twiki//bin/view/Main/OperationModel )

Slide41: 

Conclusions Many important milestones have been passed in the construction, pre-assembly, integration and installation of the ATLAS detector components Very major software, computing and physics preparation activities are underway as well, using the Worldwide LHC Computing Grid (WLCG) for distributed computing resources Commissioning and planning for the early physics phases have started strongly ATLAS is highly motivated, and on track, for first collisions in 2007 (ATLAS expects to remain at the energy frontier of HEP for the next 10 – 15 years, and the Collaboration has already set in place a coherent organization to evaluate and plan for future upgrades in order to exploit future LHC machine high-luminosity upgrades) (Informal news on ATLAS is available in the ATLAS eNews letter at http://aenews.cern.ch/)

Slide45: 

(Revised) LHC schedule as presented to CERN Council on 23 June 2006  Last magnet installed : March 2007 Machine and experiments closed : 31 August 2007  First collisions (√s = 900 GeV, L~1029 cm-2 s-1) : November 2007 Commissioning run at injection energy until end 2007, then shutdown (3 months ?)  First collisions at √s=14 TeV (followed by first physics run): Spring 2008 Goal : deliver integrated luminosity of few fb-1 by end 2008 • Sectors 7-8 and 8-1 will be fully commissioned up to 7 TeV in 2006-2007. If we continue to commission the other sectors up to 7 TeV, we will not get circulating beam in 2007. • The other sectors will be commissioned up to the field needed for de-Gaussing. • Initial operation will be at 900 GeV (CM) with a static machine (no ramp, no squeeze) to debug machine and detectors. • Full commissioning up to 7 TeV will be done in the winter 2008 shutdown L. Evans, CERN Council, 23/6/2006