Transcript ppt
Research for the
International Linear Collider
Professor Andy White
October 2005
What do we know now (2005)?
What don’t we know now (2005)!
- Why particles have mass
- Whether all four forces merge at high energies
- If we live in more than Four dimensions
- What is the Dark Matter
- What is the Dark Energy
- …?
Is there a Hiigs field that gives mass
to particles?
Contributions to the Higgs mass
Produces an infinite result due to summation over
momenta of particles in the circular loop.
A possible cure?
…add a contribution that
cancels the bad contributions:
But this requires new particles !
A better
merging if
SUSY is
included!
Many of our present questions should be
answered at the Large Hadron Collider
UTA is a member of the ATLAS
Collaboration
…but ATLAS discoveries will need
have detailed follow up and
verification before we know what
the real nature of the new physics is!
ILC - Accelerator
Luminosity :
3.4x1034 cm-2s-1 (6000xLEP)
~ 90 – 1000 GeV
Superconducting RF Technology
5 bunch trains/s
950 µs
199 ms
950 µs
2820 bunches
337 ns between collisions
Physics rates
e+e- qq 330/hr e+e- W+W- 930/hr
e+e- tt 70/hr e+e- HX
17/hr
Background rates
e+e- qq
0.1 /Bunch Train
e+e- X
200 /Bunch Train
ILC - Physics
Emphasize precision
measurements – in a
difficult environment –
many multijet final
states.
?? Optimizing the
physics for 1 or 2
detectors??
σ(e+e-gZHH) = 0.3 fb
•ZHH
SiD Detector
Solenoid
ILC – Detector Requirements
- Good momentum resolution e.g. for ZH with Z -> µµ
- Vertex resolution for flavor tagging c/b
- Good jet energy energy and jet-jet mass resolution
- Good coverage for missing energy
- Good separation of charged/photons/neutral clusters
-> Good pattern recognition, two track separation
Physics examples driving calorimeter
design
Higgs production e.g.
e+ e- -> Z h
Missing mass peak
or bbar jets
separate from WW, ZZ (in all jet modes)
Higgs couplings e.g.
- gtth from e+ e- -> tth -> WWbbbb -> qqqqbbbb !
- ghhh from e+ e- -> Zhh
Higgs branching ratios h -> bb, WW*, cc, gg,
Strong WW scattering: separation of
e+e- -> WW -> qqqq
e+e- -> ZZ -> qqqq
and e+e- -> tt
Physics examples driving calorimeter
design
-All of these critical physics studies demand:
Efficient jet separation and reconstruction
Excellent jet energy resolution
Excellent jet-jet mass resolution
+ jet flavor tagging
Plus… We need very good forward calorimetry for e.g.
SUSY selectron studies,
and… ability to find/reconstruct photons from
secondary vertices e.g. from long-lived NLSP -> G
Can we use a “traditional” approach to calorimetry?
(using only energy measurements based on the
calorimeter systems)
60%/E
H. Videau
30%/E
Target region for jet
energy resolution
Don’t underestimate the complexity!
Digital Hadron Calorimetry
Physics requirements emphasize segmentation/granularity (transverse
AND longitudinal) over intrinsic energy resolution.
- Depth 4 (not including ECal ~ 1) + tail-catcher(?)
-Assuming PFlow:
- sufficient segmentation (#channels) to allow efficient charged
particle tracking.
- for “digital” approach – sufficiently fine segmentation
(#channels) to give linear energy vs. hits relation
- efficient MIP detection (threshold, cell size)
- intrinsic, single (neutral) hadron energy resolution must not
degrade jet energy resolution.
GEM-based Digital Calorimeter Concept
GEM – production
140mm
70mm
Hole profile
Exposed kapton
Copper edges
GEM – operation
-2100V
∆V ~400V
∆V ~400V
0V
305mm x 305mm layer
Trace edge
connector ->
Fermilab 32 ch
board
Disc/DAQ
under
design by
U.W.
(10 x 10) – 4
active area = 96
channels
First 30cm x 30cm 3M GEM foils
Development of GEM sensitive layer
Gas inlet/outlet
(example)
Absorber strong back
Cathode layer
Non-porous,
double-sided
adhesive strips
Anode(pad) layer
Fishing-line spacer
schematic
3 mm
1 mm
1 mm
9-layer readout pc-board
(NOT TO SCALE)
GEM foils
DHCAL/GEM Module concepts
GEM layer
slides into
gap between
absorber
sheets
Side plates alternate in
adjacent modules
Include part of absorber in
GEM active layer - provides structural
integrity
“Window for Detector R&D
2004
2005
2006
2007
2008
GDE (Design)
2009
2010
(Construction)
Technology
Choice
Acc.
CDR
TDR
Start Global Lab.
Done!
Det.
Detector Outline
Documents
CDRs
LOIs
Detector R&D Panel
Detector
R&D Phase
Collaboration
Forming
Construction
Tevatron
SLAC B
HERA
LHC
T2K
Timeline of Beam Tests
2005
2006
2007
2008
2009
>2009
CALICE SiW ECAL
OTHER ECALs
CALICE TILE
HCAL+TCMT
CALICE DHCALs and others
ILCD R&D,
calibration
Combined CALICE TILE
Combined Calorimeters
m, tracking, MDI, etc
PFA and shower library Related Data Taking
Phase 0:
Prep.
Phase I: Detector R&D, PFA
development, Tech. Choice
Phase II
From Jae Yu
Many challenging and exciting
projects on Linear Collider R&D!
-> Detector design
-> Prototype construction/testing
-> High speed electronics
-> Computer simulations (need help!)
-> Physics studies (need help!)
[email protected] x22812 Room 241