Compact Muon Solenoid Detector - Indico€¦ · Piotr Traczyk NCBJ Warsaw/CERN. 2 CMS detector...
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The Compact Muon Solenoid Detector Piotr Traczyk NCBJ Warsaw/CERN
Transcript of Compact Muon Solenoid Detector - Indico€¦ · Piotr Traczyk NCBJ Warsaw/CERN. 2 CMS detector...
TheCompact Muon Solenoid
Detector
Piotr TraczykNCBJ Warsaw/CERN
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CMS detector overview
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The CMS Solenoid● CMS is built around a superconducting solenoid
generating a magnetic field of 4 Tesla● The current necessary for this – 20 kA...● Superconducting NbTi wire cooled to ~4K● 13m length, 6m inner
diameter – enough to fit the tracker and calorimeters inside
● (cost ~80 MCHF)
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ATLAS A Toroidal LHC Apparatus
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CMS Compact Muon Solenoid
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Magnets in particle detectors
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Two ways to detect a particle (in CMS)
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Two ways to detect a particle (in CMS)
See the track Or Catch
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Two ways to detect a particle (in CMS)
Tracking detector Or
Calorimeter
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Particle identification in CMS
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The Inner Tracker● Measures the trajectories of
charged particles momentum = 1/curvature
● The biggest silicon detector in history, over 220m2 of silicon
● Inner part – 3 layers of pixel detectors, outer part 10-11 layers of silicon microstrips
● 75 141 milions of read-out channels
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Event „pile-up”
In the LHC, several proton-proton collisions can occur in a single bunch crossing (The image shows an event with 29 reconstructed vertices)
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Electromagnetic Calorimeter● Electron and photon energy measurement● ~75 000 PbWO
4 crystals
● Homogeneous detector - crystals act as both the absorber and the scintillator
● Very good energy resolution
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Hadron Calorimeter ● Jet energy measurement● Brass absorber interleaved
with scintillator layers● Steel blocks with embedded quartz fibers in the
„forward” part
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The Muon System – Drift Tubes● Muon trajectory measurement (barrel)● Measured quantity – drift time of
electrons produced by the passing muon● Known drift velocity distance →
measurement (~50-200mm precision)● Alignment very important
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Trigger
The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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The H → gg channel
One of these plots contains the (simulated) Higgs boson signal.
Can you spot it?
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Once more:
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A proton-proton collisionas seen by CMS
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The End
