Transcript Frey-DoE Review, Jan 2006

LC Detector R&D, SLAC, and SLUO…
pre-P5 meeting
R. Frey, University of Oregon
Detector R&D will have a huge positive impact on the physics program of
the TeV-scale LC.
 We see how to make big steps in performance over the LEP/SLC
generation of detectors. And there is additional untapped potential.
 These steps will “possibly” be crucial for elucidating the New Physics.
 Major labs and their users should play a meaningful role.
Outline:
• The LC challenges for detectors
• Snapshots of some current R&D involving SLAC and users
• SLAC as a center for LC R&D
R Frey
SLUO P6
1
The TeV Scale – What will it bring?
H. Murayama
We know
there is New
Physics, but
we don’t know
what it is.
The LHC will
uncover (choose):
a) all the New
Physics
b) a known portion
c) an unknown
portion
R Frey
SLUO P6
2
Jet (hadronic) final states at LHC
D. Green, Calor2002
LHC Study: Z→ 2 jets
• FSR is the biggest effect.
Z -> JJ , Mass Resolution
• The underlying event is
the second largest error (if
cone R ~ 0.7).
dE (Calor)
Fragmentation
Underlying Event
Radiation
B=4T
• Calorimeter resolution is
a minor effect.
σM / M  13% without FSR
 At the LC, the situation is reversed: Detection dominates.
 Opportunity at the LC to significantly improve measurement of jets.
R Frey
SLUO P6
3
LC environment: interaction rate; accelerator timing
ILC
(SC RF)
• Cross section is small  0 or 1 event per bunch crossing
 No underlying events (pairs swept forward)
 Little or no radiation damage
• All events are interesting  no trigger (record everything)
• Long time between bunch trains  turn off (most) power in FE
 Can use passive cooling  very light tracking systems
• Small IP  can get very close with vertex detectors
R Frey
SLUO P6
4
LC detector goals
• In general, LC measurements are
limited by the detectors (and
luminosity, s), not by the collider
environment.
• LC detectors should aim to measure
all final states and measure with
precision.
 Multi-jet final states
• With or without beam constraint
 Leptons
• including tau
 Heavy quarks
 Missing energy/mass
 Collision energy and polarization
R Frey
SLUO P6
5
Meeting the challenges I: PFA for multi-jet final states
2% at
100 GeV
+ confusion = 3-4% at 100 GeV
Typical jet content:
• This is >2x better
than previous
collider detectors
• Key is minimizing
confusion:
1. Algorithms
2. Calorimeter
segmentation
R Frey
SLUO P6
6
Steve Magill: PFA Illustration
t tbar  6 jets
R Frey
SLUO P6
7
The SiD Si/W ECal
Layers tiled with silicon sensors,
each with 1024 13 mm2 pixels
KPiX chip
R Frey
SLUO P6
8
Si-W Pixel Analog Section
Dynamic gain1 of 1024 pixels
select
one channel of 1024
Low Gain
Si pixel
Range Logic
Reset
Range Register
KPiX chip (SLAC,
Oregon, BNL)
Wilkinson
scaler and
logic
13 bit
A/D
Latch (4x)
Reset
High Gain (default)
I
Source
Range Threshold
Track
Storage until
.
end of
train.
.
Analog 1
Control Logic
Pulses to Timing Latch,
Range Latch, and Event
Counter
Leakage Current Servo
Leakage
current
subtraction
Event Threshold
.
Reset
Analog 4
Track
Bunch Clock
Cal Dac
Event trigger
Cal Strobe
Pipeline
depth
presently is 4
calibration
Simplified Timing:
There are ~ 3000 bunches separated by ~300 ns in a train, and trains are separated by ~200 ms.
Developed for Si/W ECal
and Si strip Tracker.
Being considered for GEM
HCal, muon system, FCal.
Say a signal above event threshold happens at bunch n and time T0.
The Event discriminator triggers in ~100 ns and removes resets and strobes the Timing Latch (12 bit), range latch (1 bit) and Event Counter (5 bits).
The Range discriminator triggers in ~100 ns if the signal exceeds the Range Threshold.
When the glitch from the Range switch has had time to settle, Track connects the sample capacitor to the amplifier output. (~150 ns)
The Track signal opens the switch isolating the sample capacitor at T0 + 1 micro s. At this time, the amplitude of the signal at T0 is held on the Sample Capacitor .
Reset is asserted (synched to the bunch clock) . Note that the second capacitor is reset at startup and following an event, while the high gain (small) capacitor is reset each bunch crossing (except
while processing an event)
The system is ready for another signal in ~1.2 microsec.
After the bunch train, the capacitor charge is measured by a Wilkinson converter.
R Frey
SLUO P6
9
(some) implications of excellent jet measurement
• multi-jet masses in the absence
of beam constraints,
e.g. WW vs ZZ, W/Z  jets
TESLA TDR
• reducing combinations with
intermediate jet masses,
e.g. ZHH  jets
• segmented, imaging
calorimeters open up new
measurements,
e.g. tau id and polarization;
non-pointing photons (GMSB)
R Frey
SLUO P6
 +   +
(+o) 
10
Meeting challenges II: tracking
SiD vtx+tracker
R Frey
SLUO P6
11
Meeting challenges III: vertexing
R Frey
SLUO P6
12
(some) implications of excellent tracking/vertexing
Yamashita
R Frey
SLUO P6
13
Meeting challenges IV: L.E.P.
e.g. t-tbar threshold
A Luminosity Spectrum dL/dE
• Contributions
1. ISR
2. Beamstrahlung
3. Linac energy spread, E/E
•
“(Eo) + tail”
Broadening near Eo
Need to measure dL/dE
R Frey
SLUO P6
14
University-SLAC detector R&D projects
(incomplete)
Groups
R&D activity
Annecy, UC Davis, Oregon (, BNL)
Silicon/tungsten ECal
Brown, Michigan, New Mexico, Purdue,
Santa Cruz, Tokyo, Washington (, FNAL)
Silicon tracking and vertexing
Colorado, Kansas, Kansas State, N. Illinois,
Iowa, Oregon, Santa Cruz (, ANL, FNAL)
Simulations, Reconstruction, PFA
development
Oregon
Beam Energy measurement
(synchrotron spectrometer)
Cambridge U., DESY, Dubna,
Royal Holloway U., U. of Notre Dame,
University College London, UC Berkeley
Beam Energy Measurement
(BPM spectrometer)
Tufts
Polarimeter backgrounds
(BNL,) Yale, Colorado, DESY
Far-forward calorimeters
R Frey
SLUO P6
15
SLAC test beam users for LC R&D
(M. Woods)
Groups
Test Beam activity
Cambridge U., DESY, Dubna,
Royal Holloway U., U. of Notre Dame, University
College London, UC Berkeley, SLAC
Beam Energy Measurement
(BPM spectrometer)
U. Oregon, SLAC
Beam Energy Measurement
(synchrotron spectrometer)
U. of Oxford, Rutherford Appleton Lab, U. of Essex,
Dartmouth College, SLAC
Beam profile measurements
(Smith-Purcell radiation)
Oregon, SLAC
EMI effect on Vertex
detectors
SLAC
KPiX readout of Si strips
U. of Birmingham, CCLRC (UK), CERN
Manchester U., Lancaster U., DESY,
TEMF TU Darmstadt, SLAC
Collimator wakefield studies
U. of Oxford, Daresbury Lab, SLAC
IP BPM studies (FONT)
R Frey
SLUO P6
16
Why a SLAC Center for R&D?
• It already is at some level… SLAC-based activity should
increase with the U.S. LC effort.
• The presence of a LC on site!!
 Unique national/international capability
 Detector test beams
 Accelerator instrumentation test beams
 The test beams are great (several personal experiences)
• Well-defined position, time, and energy
 With a LC bunch timing structure(!)
• Local detector/instrumentation expertise and infrastructure
 Electronics group
 HEP-related engineering
 Detector experts
 Computing facilities and simulation/software group
• Location
• Historical user base
R Frey
SLUO P6
17