Getting ready Getting ready for the LHC for the LHC Gnther - PowerPoint PPT Presentation

Getting ready Getting ready for the LHC for the LHC Günther Dissertori ETH Zürich Galileo-Galilei Institute Firenze 16.6.2006

Outline  Introduction  Now : Status of the  Machine  Detectors  Pretty soon : Commissioning and start-up scenarios of the  Machine  Detectors  Soon  Pilot and first Physics run  Further aspects  Learn amap from the data H → ZZ → 4 ℓ  Some comments 16.6.06 G. Dissertori 2

What I will (not) offer here: I will talk about  Introduction A very brief overview of the hardware preparations of Status of  • the machine Machine • ATLAS and CMS Detectors Startup of Explain the startup Machine  • Why is the LHC startup planned in this particular way? Detectors • What are the initial challenges for the detectors First Physics Comments Pilot run and first year  • What can we do with pilot run data? • First the first year’s data Some comments about  • Use of data to constrain backgrounds, MCs • Use of MCs I will not talk about  LHCb and ALICE (sorry for that…)  All the wonderful physics we can do (from NNNMSSM to Black Holes)  All the details of Higgs and SUSY searches  Data challenges, Data flow, ATLAS Blind test  16.6.06 G. Dissertori 3

Our future play ground pp, B-Physics, Introduction CP Violation Status of LHC : 27 km long Machine 100m underground Detectors Startup of Machine Detectors ATLAS First Physics Comments General Purpose, General Purpose, pp, heavy ions pp, heavy ions Heavy ions, pp CMS ALICE +TOTEM 16.6.06 G. Dissertori 4

Introduction Status of Machine Detectors Now : Startup of Machine Detectors Status of the LHC First Physics Comments and the Detectors “The greater the obstacle, the more glory in overcoming it.” (Moliere) 16.6.06 G. Dissertori 5

The LHC : Basic parameters Introduction +TOTEM Status of Machine Detectors Startup of Machine Detectors First Physics Phys. Reach 1232 superconducting dipoles  15m long at 1.9 K, B=8.33 T  Inner coil diameter = 56 mm x 200  beam-energy 7 TeV ( 7x TEVATRON)  10 34 cm -2 s -1 (>100x TEVATRON) Luminosity  Bunch spacing 24.95 ns  Particles/bunch 1.1 10 11  Stored E/beam 350 MJ  10 GJ stored in magnets  Also : Lead Ions operation  Energy/nucleon 2.76 TeV / u  Total initial lumi 10 27 cm -2 s -1  16.6.06 G. Dissertori 6

The LHC : Status report Lowering of the first dipole into the tunnel Introduction (March 2005). Status of Machine By now there are > 500 dipoles Detectors Startup of New schedule to be announced next Machine week… Detectors First Physics Comments Cryogenic services line inter-connections 16.6.06 G. Dissertori 7

The LHC : Status report Introduction Status of Machine Detectors Startup of Machine Detectors First Physics Comments See : http://lhc-new-homepage.web.cern.ch/lhc-new-homepage/DashBoard/index.asp 16.6.06 G. Dissertori 8

ATLAS Muon Spectrometer ( | η |<2.7 ) Introduction  air-core toroids with muon chambers Status of Machine Detectors Startup of Machine Detectors First Physics Comments Tracking ( | η |<2.5, B=2T )  Si pixels and strips  TRD (e/ π separation) Diameter 25 m Calorimetry ( | η |<5 ) Barrel toroid length 26 m  EM : Pb-LAr End-cap end-wall chamber span 46 m  HAD : Fe/scintillator (central), Overall weight 7000 tons Cu/W-Lar (fwd) 16.6.06 G. Dissertori 9

ATLAS : Status report Introduction Status of Machine Detectors Startup of Machine Detectors First Physics Comments Toroids : 8 out of 8 coils installed. End of coil installation early Aug 05. NOV 8, 2005 NOV 8, 2005 16.6.06 G. Dissertori 10

CMS Superconducting CALORIMETERS Introduction Coil, 4 Tesla HCAL ECAL Status of 76k scintillating Plastic scintillator/brass PbWO4 crystals sandwich Machine Detectors Startup of IRON YOKE Machine Detectors First Physics Comments TRACKER Pixels Silicon Microstrips 210 m 2 of silicon sensors 9.6M channels MUON MUON BARREL ENDCAPS Total weight 12500 t Drift Tube Resistive Plate Overall diameter 15 m Chambers ( DT ) Cathode Strip Chambers ( CSC ) Chambers ( RPC ) Overall length 21.6 m Resistive Plate Chambers ( RPC ) 16.6.06 G. Dissertori 11

CMS : Status report Cosmic muon Comissioning of the muon system... 16.6.06 G. Dissertori 12

CMS : Status report Introduction Status of Machine Detectors Startup of Machine Detectors First Physics Comments Magnet Insertion: Autumn 05 ; Cooled down early in 2006 16.6.06 G. Dissertori 13

CMS : Status report Introduction Status of Machine Detectors Startup of Machine Detectors First Physics Comments 16.6.06 G. Dissertori 14

Magnet Test and Cosmic Challenge  Check functionality of all Introduction magnet systems CMS closed for Magnet test Status of in the SX5 surface building Machine Detectors  (April/May 2006) Map the magnetic field Startup of Machine  Detectors Check installation & cabling First Physics of Comments  ECAL/HCAL/Tracker inside coil  Test combined sub- detectors in 20 degree slice(s) of CMS with Magnet. Try out operation procedures for CMS (24/7 running) 16.6.06 G. Dissertori 15

CMS : lowering Introduction Status of Machine Detectors Startup of Machine Detectors First Physics Comments 15 heavy lifts in 2006, 1 week duration each. Heaviest piece : 2k tons 16.6.06 G. Dissertori 16

Introduction Status of Machine Detectors Startup of Pretty soon: Machine Detectors First Physics Comments Commissioning and start-up scenarios “If we wait for the moment when everything, absolutely everything, is ready, we shall never begin.” (Ivan Turgenev) 16.6.06 G. Dissertori 17

LHC : Performance Limitations Legend: Introduction Parameter/Effects Limitations Status of N : particles/bunch Machine Beam energy n : nr. of bunches Detectors limited by maximum dipole field. Industrially 7 TeV I : current / beam available technology. Startup of Machine ε n = εγ , ε : emittance Bunch and total beam intensity N < 1.7 10 11 Detectors β * : β at IP beam-beam effect (tune spread), small allowed N nom = 1.15 10 11 First Physics space in Q-space, collimators (impedance, Beam size σ 2 = βε collective instabilities), electron cloud, radiation I < 0.85 A Comments Q : tune (number of Normalized emittance trans. oscil./turn) ε n <3.75 µ m Basically given by injector chain and limited by Tune spread main dipole aperture Δ Q ∝ N / ε n Beam size at IP ( β * ) β * > 0.55 m Limited by (triplet) quadrupole aperture σ ~ 16 µ m Number of bunches 2808 Limited by stored beam energy, electron cloud eff. Operation efficiency and L int Total beam intensity minimize quenches and beam aborts, collimators and cleaning important: N lost < 7 10 8 /m = 2.2 10 -6 N 16.6.06 G. Dissertori 18

LHC : Performance Limitations Introduction Current in machine Status of N : particles/bunch Machine n : nr. of bunches Detectors I : current / beam Startup of ε n = εγ , ε : emittance Machine Detectors β * : β at IP First Physics Beam size σ 2 = βε Comments Q : tune (number of trans. oscil./turn) Tune spread Δ Q ∝ N / ε n Luminosity Beam size 16.6.06 G. Dissertori 19

LHC : Performance Limitations  Two Examples: Magnet aperture, beam-beam, collimators Introduction Status of Machine Detectors Startup of Machine Detectors First Physics s Comments ~23m σ *=16.6 µ m σ (triplet)=1.54 mm Badly conducting collimators : large wake fields : instability Phase 1 : graphite (robust), I < 0.3 A Phase 2 : Cu (good conduct.) I < 0.85 A 16.6.06 G. Dissertori 20

LHC : Start-up scenario Stage 1 Objective : establish colliding beams as quickly as  possible, safely, without compromising further progress Introduction Initial commissioning Take two moderate intensity multi-bunch beams to high energy and Status of  43x43 to 156x156, N=3x10 10 collide them : minimize problems due to electron cloud, event pile- Machine Zero to partial squeeze up, equipment restrictions, use phase 1 collimators. Detectors L=3x10 28 - 2x10 31 Startup of Machine Stage 2 Detectors 75 ns operation First Physics 2007 936x936, N=3-4x10 10 Comments partial squeeze L=10 32 - 4x10 32 Stage 3 25 ns operation 2808x2808, N=3-5x10 10 partial to near full squeeze 2008 L=7x10 32 - 2x10 33 Stage 4 25 ns operation Push to nominal per bunch partial to full squeeze L=10 34 16.6.06 G. Dissertori 21

Detector Commissioning  Construction quality checks and beam tests of series Introduction detector modules show that the detectors as built should Status of give a good starting-point performance Machine Detectors  However, a lot of data (and time …) will be needed at the Startup of Machine beginning to Detectors First Physics Comments  Commission the detector and trigger in situ  Reach the performance needed to optimize the physics potential  Understand “basic” physics at 14 TeV and normalize (tune) the MC generators  Measure backgrounds to new physics and extract “early” convincing signals  Efficient/extensive/robust commissioning programme with physics data is therefore crucial to reach quickly the “discovery” mode 16.6.06 G. Dissertori 22