CMS at UCSB. Prof. J. Incandela US CMS Tracker Project Leader DOE Visit January 20, 2004. Experimental Focus. Some of the questions LHC Experiments could resolve: What is the origin spontaneous symmetry breaking ? What sets the known energy scales ?
Prof. J. Incandela
US CMS Tracker Project Leader
January 20, 2004
What is the origin spontaneous symmetry breaking ?
What sets the known energy scales ?
QCD ~ 0.2 « VEVEWK ~ 246 « MGUT ~ 1016 « MPL ~ 1019 GeV
What comes next ?
27 km around
1100 dipole magnets
14 m long
8.4 T field
Proton on proton: 14 TeV
25 ns between beam crossings
Peak Luminosity 1034 cm-2 s-1
20 collisions per beam crossing
Total cross-section is very high!
What’s interesting is rare
The ability to find any of these events is a consequence of evolved detector design and technological innovations:
Multi-level trigger systems and high speed pipe-lined electronics
Precision, high rate, calorimetry
Radiation-tolerant Silicon microstrips and Pixel detectors
Production and Decay
To a large extent, the quest for the Higgs drives the design of the LHC detectors.
Nevertheless, essentially all other physics of interest require similar capabilities
Lepton id, b tagging and ET are crucial
Difficult (or impossible)
Energy resolution must be exceptional, tracking is crucial
Most Ambitious Elements:Calorimetry & Tracking
Inside of the 4 Tesla field of the largest SC Solenoid ever built
Pixels: at least 2 Layers everywhere
Inner Si Strips: 4 Layers
Outer Si Strips: 6 Layers
Forward Silicon strips: 9 large, and 3 small disks per end
EM Calorimeter: PbWO4 crystals w/Si APD’s
Had Calorimeter: Cu+Scintillator Tiles
Outside: Muon detectors in the return yoke
Efficient & robust Tracking
Reconstruct high PT tracks and jets
Outer Barrel (TOB)
End Caps (TEC 1&2)
Inner Barrel & Disks
(TIB & TID)
volume 24.4 m3
running temperature – 10 0C
Why Pixels ?
Peak occupancy ~ 0.01 %
Starting point for tracking
6 layers of 500 mm sensors
high resistivity, p-on-n
9+3 disks per end
Blue = double sided
Red = single sided
4 layers of 320 mm sensors
low resistivity, p-on-n
Strip lengths range from 10 cm in the inner layers to 20 cm in the outer layers.
Strip pitches range from 80mm in the inner layers to near 200mm in the outer layers
6,136 Thin wafers 300 μm
19,632 Thick wafers 500 μm
6,136 Thin detectors (1 sensor)
9,816 Thick detectors (2 sensors)
3112 + 1512 Thin modules (ss +ds)
4776 + 2520 Thick modules (ss +ds)
10,016,768 individual strips and readout electronics channels
78,256 APV chips
470 m2 of silicon wafers
223 m2 of silicon sensors (175 m2 + 48 m2)
FE hybrid with FE ASICS
0.25 mm radiation-hard CMOS technology
128 Channel Low Noise Amplifier
~8 MIP dynamic range
50 ns CR-RC shaper
192 cell analog pipeline
Differential analog data output
The Standard Model Higgs can be discovered over the entire expected mass range up to about 1 TeV with 100 fb-1 of data.
Most of the MSSM Higgs boson parameter space can be explored with 100 fb-1 and all of it can be covered with 300 fb-1.
squarks and gluinos up to 2 to 2.5 TeV or more
SUSY should be observed regardless of the breaking mechanism
The figure shows the q, g mass reach for various luminosities in the inclusive ET + jets channel.
UCSB could play a significant role here…
LED: Sensitive to multi-TeV fundamental mass scale
SED: Gravitons up to 1-2 TeV in some models
If Electroweak symmetry breaking proceeds via new strong interactions something new has to show up
New gauge bosons below a few TeV can be discovered
If the true Planck scale is ~ 1 TeV, we may even create black holes and observe them evaporate…
This is an outstanding program.
It requires unprecedented cost and effort.
It is not guaranteed…
NEW:End Caps (TEC)
50% Modules for Rings 5 and 6 and hybrid processing for Rings 2,5,6
Outer Barrel (TOB)
Carbon Fiber Frame
US and UCSB in the CMS tracker
UCSB carries majority of US production load
Modules Built & Tested at UCSB
(more in talk by Dean White)
Module Built & Tested at UCSB (more in talk by Dean White)
4-Hybrid test stand and thermal cycler
(subject of talk by Lance Simms)
(see talk by Tony Affolder)
CMS is designed to maximize LHC physics
The tracker is one of the main strengths of CMS
UCSB is making critical contributions
Have proven to be essential to the success of the project
Details of the important aspects of the project and the important achievements of the UCSB CMS group in the past year as presented by the people responsible for them.