Physics and Detector Studies in Japan Akiya Miyamoto KEK ILC Korea meeting @ PAL 17 February 2006
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Transcript Physics and Detector Studies in Japan Akiya Miyamoto KEK ILC Korea meeting @ PAL 17 February 2006
Physics and Detector
Studies in Japan
Akiya Miyamoto
KEK
ILC Korea meeting @ PAL
17 February 2006
1
Physics Scenario at ILC
2
ILC Detector Performance Goals
(http://blueox.uoregon.edu/~lc/randd.pdf)
Vertexing
(h bb ,cc , )
~1/5 rbeampipe,~1/30 pixel size (wrt LHC)
ip 5 m 10 m / p sin 3 / 2
(e e Zh
X; incl. h nothing)
Tracking
~1/6 material, ~1/10 resolution (wrt LHC)
(1/ p) 5 105 /GeV
Or better
Jet energy (Higgs self-coupling, W/Z sep. in SUSY
study)
~1/2 resolution (wrt LHC)
E / E 0.3 / E (GeV )
3
Detector for ILC experiments
Detector design Philosophy
Muon detector
Calorimeter
Good jet energy resolution
g calorimeter inside a coil
g highly segmented calorimeter
Efficient & High purity b/c tagging
Coil
g Thin VTX, put close to the IP
g Strong solenoid field
g Pixel type
High momentum resolution
Hermetic down to O(10)mrad
Tracker
Vertex
detector
Shielded enough against beamrelated background
4
Concepts - Technologies
5
GLD Concept
Pixel vertex detector + Si tracker, self-tracking capable
Large gaseous central Time Projection Chamber (TPC)
Large radius, “Medium/High” granularity ECAL: W-Scitillator
“Medium/High” granuality HCAL: Pb-Scintillator inside 3T solenoid
6
Comparison to other concepts
SiD
LDC
GLD
GLD: Large ECAL radius
good for better jet energy
resolution
7
Our Activities
Concept Study
GLD : as an inter-regional team DOD
Home page: http://ilcphys.kek.jp/gld/
Software studies
Simulation and Reconstruction based on full simulation
Vertex Detector
TPC
Calorimeter
Some topics of recent activities will be presented
Apologies for not covering all
8
Software activities
Development of tools and studies based on them
Geant4 based full simulator, Jupiter and analysis tools, Satellites
Study items
Particle Flow Analysis
–
–
–
–
By cheated method
By realistic method
Performance comparison: digital vs analog, tile size, etc.
Better understanding of hadron shower programs
Tracking
– Khalman track fitter for TPC/IT/VTX
– Track reconstruction
Backgrounds in tracker
Physics performances
They will be described in the GLD DOD in detail
9
Detector Geometry
in Dec. 2005
Full One Tower
EM + HD
6.1λ
27 X0
New Geometry in Jupiter
(Feb, 2006)
10
Perfect PFA
Perfect track-calorimeter matching based on Monte Calor Info.
Shower fluctuation, particle interactions with material fully simulated
Identify terms contributing to the resolution to design the best detector
u,d,s quark pair
Events at Z pole
including a best kink track treatment:
improves kink ~ 1.3 GeV
11
PFA : error source
Contribution to Jet Energy Resolution
Effect of Pt cut
Neutrino
5mrad cut
Low Pt track
TPC Resol.
EM Cal Resol.
HD Cal Resol.
Total
0.30 GeV
0.62
0.83
0
1.36
1.70
2.48
B=6T
Important to measure low Pt track
for the best energy resolution !
12
Realistic PFA
Critical part to complete detector design
Large R & medium granularity vs small R & fine granularity
Large R & medium B vs small R & high B
Red : pion
Importance of HD Cal resolution vs granuality
Yellow :gamma
…
Blue : neutron
Algorithm developed in GLD:
Consists of several steps
MIP finding
Gamma Finding
Small-clustering
Cluster-track matching
Neutral hadron clustering
ee+
13
PFA performance so far
Z-pole events
Further improvement
necessary to
Achieve 30%/Sqrt(E)
Similar resol.
At higher energy
Optimize detector w.r.t
jet energy resolution
14
Higgs Study
e+e- ZH 4-jet or 2-jet + missing :
Studied assuming the cheated PFA performance, using QuickSim
Study assuming the realistic PFA performance is in progress
Other channels such as ZHH or SUSY processes need to be studied
15
Higgs mass : if Mh=120GeV
e e
X;
e,
Differential Luminosity(500GeV)
DE/E(beam)~0.1%
Incl. beamstrahlung
350GeV, nominal
(Mh)~109MeV
s / sno min al
Incl. beamstrahlung
350GeV, high-lum
(Mh)~164MeV
Incl. beamstrahlung
250GeV, nominal
(Mh)~27MeV
16
Forward Region for SUSY Study
MUD
FCAL Front and Tail: 30 layers of 3mm Thick
Tungsten + 0.3mm thick Si + Air gap
CH2 Mask
TPC
QC1
Response to 10GeV e+
BCAL
EMCAL
BCAL : Total Z length 20 cm
30 layers of 3mm thick Tungsten
+ 0.3mm thick Si. + Air gap
FCAL
17
Background
Low energy e+e- pair background in BCAL region.
Simulated using CAIN data, 500 GeV, Nominal parameter
~1/65 bunch of pair backgrounds are simulated
BCAL
e+/e- tagging in the forward region ?
Needs serious study for SUSY physics
FCAL
18
VTX R&D in Japan
Challenge of ILC Vertex detector
To achieve performance goal, vertex detector has to
Thin(< 100mt si/layer) pixel device, pt < 5m, # layer > 3
Bunch spacing, ~300nsec, is too short to readout O(1) Giga pixels,
but occupancy is too high if accumulate 3000 bunches of data with a
standard pixel size of ~ 20x20m2.
No proven technology exist yet. Candidates are,
Readout during train
CPCCD, MAPS, DEPFET, …
Local signal storage, and readout between train
ISIS, CAP, FAPS, …
Fine Pixel, readout between train
FPCCD (5x5m2 pixel CCD)
In Japan, we (KEK-Tohoku-Niigata collaboration) are proposing Vertex
Detector using Fine Pixel CCD (FPCCD)
We believe FPCCD is the most feasible option among the proposed
technologies
19
FPCCD Chip
5m pixels, to reduce occupancy
Promising, because Fine pixel CCD device exists already for optical
applications
Fully depleted epitaxial layer to suppress charge spread by diffusion
Multi-port readout with moderate (~ 15MHz) readout
Low temperature operation to keep dark current negligible for
200msec readout cycle.
20
FPCCD Vertex Detector
2 layers Super Layer, 3 super layers in total
minimize the wrong-tracking probability due to multiple scattering
6 layers for self-tracking capability
Cluster shape analysis can help background rejection
Baseline design for GLD
21
Background rejection by cluster shape
dW (WZ BG WZ Sig ) 2 (WBG WSig ) 2
WZSig, WSig: Expected width
A big advantage of Fine Pixel Sensors
22
B.G. rejection by cluster shape
R=20 mm
Cut at dW=10 m
Ratio
All
dW<10m
Z (mm)
1/20
Z (mm)
23
Status of sensor R&D
Fully depleted CCD for astrophysics by Hamamatsu
24 m, 12 m pixel size:
Available now
We will test them soon : Charge spread, Lorentz angle
5 – 9 m pixel size:
Under development
Will be available in 0.5 – 1 year
Custom fully depleted FPCCD for VTX
High speed (~15MHz)
Multi-port readout
We wish to start in 2006
24
Challenge of TPC technology
Principle of TPC
Central
Membrane
Pad Plane
........
E
Bz
Drift Time Z position
Position at Pad plane
rposition
Challenges
To achieve r<150m after long
drift of > 2m
MWPC MPGD readout
R&D issues
Gas amplification in MPGD : GEM,
MicroMegas
Properties of chamber gas:
drift velocity, diffusion
Ion feedback control
25
TPC R&D
A series of beam tests has been done at KEK PS, to study performances
Of TPC using readouts of MWPC, GEM, and MicroMegas
26
Beamtest setup
MPI Field Cage
26cmL
KEK PI2 beamline
Beam
1T Magnet
86cm, 1mL
Readout Pad
10cmx10cm
For MWPC, GEM,
MicroMegas
27
MWPC vs GEM
28
B Field Dependance
Bfield improves spatial
resolution significantly.
ILC
Target
For long drift, diffusion term
dominates the spatial
resolution.
Calculated results of CD are
more or less consistent with
test results.
probably OK to extrapolate
to 3~4T
need to be confirmed by
future tests with large B
field and long drift.
29
Comparison with Numerical Calculation
Neumerical Calculation (by K.
Fujii)
MicroMEGAS
Pad : 2.3 mm
Diffusion Constnat :
469, 285 and 193 m/ cm
for
B = 0, 0.5 and 1.0 T
Neff = 27.5
f : function
2.3 mm / 12
Data: MicroMEGAS
B=1T
Gas: Ar-isobutane (5%)
Pad: 2.3 mm Pads
Data
X2 X2 0 D 2 / N eff z
D/
N eff 38.4 9.7 m/ cm
X 0 129 53 m
diffusion dominant
asymptotic region
Resistive Anode or Digital
Resolution with short drift length
is dominated by
Readout pad pitch
Width of induced charge on pad
plane.
KEK Beamtest : MicroMegas TPC and
a registive anode readout
To increase pad picth
Digital TPC : O(100m) pad size
and readout Future possibility
Increase signal width
Resistive anode pad readout,
but two track separation might be
scarified
31
Plan of TPC R&D
Study properties of MPGD, GEM and MicroMegas, and gas
amplification mechanism well Simulation/ test bench studies
Study chamber gas properties and amplification in MPGD
Drift velocity, diffusion constants, …
For ILC application, gas with no H is preferred to reduce effects of
neutrons background.
Positive ion feed back has to be reduced sufficiently
Study properties of MPGD with large prototype EUDET
Design and develop a large TPC system with electronics.
32
Calorimeter
Design goals
Fine granularity, O(1) cm, for the best track-cluster matching
Crucial for best jet energy resolution
Hermetic down to O(10)mrad
Elemag and hadron calorimeters are both inside Coil
Challenge:
Achieve sufficient granularity with a reasonable cost
Optimize configuration to satisfy design goals.
Develop best PFA. Hardware configuration best meats PFA algorithm
Our choice:
Scintillator based calorimeter
33
Calorimeter Configuration
EM Configuration :
Tungsten-Scintillator Strip
Large inner radius
Small Moliere radius
Fine Granuarity
Distance of g from p0 at r=210cm
O(1) cm segmentation is necessary
HD CAL: Lead-Scinti. Sandwitch
Active Sensor:
Strip/Tile combination
34
GLD CAL Configuration
12 sided shape:
EM CAL
HD CAL
Readout cable goes between HD CAL module
to minimize dead space in EM
35
Photon Sensor R&D
Merits of Silicon Photon Pixel Sensor
Work in Magnetic Field
Very compact and can directly mount on the fiber
High gain (~106) with a low bias voltage (25~80V)
Photon counting capability
~1cm
SiPM case:
O(100) pixels,
Each pixel is in
Geiger mode.
# hit pixel
= # input lights
36
>2000 pix
For GLD
37
Status and Plans on Calorimeters
ECAL large prototype in progress
Sci-strip type
HCAL large prototype needs funding!
SiPM/MPPC promissing and testing in progress
More PFA study painfully needed
Optimization for high-energy jets (granularity)
Scintillator strip design works?
38
Detector Timeline
Accelerator
(2005 end) Acc. Baseline
Configuration Document (BCD)
Detector
Detector R&D report
(2006,3)
“Detector outline documents”
(one for each detector concept)
(2006 end) Acc. Reference
Design Report (RDR)
Detector Concept Report (DCR :
one document)
(~2008) LC site EOI
Collaborations form
~Site selection + 1yr
Global lab selects experiments.
By H.Yamamoto
39
Summary
Detector Outline Document will be released soon. But there are
many issues yet to be studied. Detector Concept Study will
continue further towards DCR.
Studies of detector technologies are in progress for Vertex
Detector, TPC, and Calorimeter. In all items, regional and interregional cooperation will be strengthened towards detector
LOI/TDR in several years:
Japan-Korea joint studies on Calorimeter
EUDET: TPC and Calorimeter
Calorimeter beam tests in FNAL with CALICE
… more
Detector R&D needs more funding
40
Backup slides
41
More missing items
Muon system is probably easy in concept but difficult in practice (large
system - support, etc.) - Missing R&D item!
Solenoid and compensation coil (DID - for large xing angle) : non-trivial
problem to realize, and DID is a problem to solve for trackers and bkg.
Forward regions (endcap regions) are important for t-channel
productions such as
e e h
Very forward regions (FCAL, BCAL) are critical for tagging electrons for
SUSY pair creations : recently attacked by Korean groups (thanks!)
With the long train, DAQ is not a trivial problem
(now P. LeDu alone for GLD)
Needs more people for beam background simulations
42
43
Beam tests are crucial
Cal. Performance depends on
cut values.
Reported to be solved in the
latest Geant4 release (8.0)
Beam test and hadron shower
simulation is not consistent.
Can we use it for the design of
highly segmented calorimeter ?
Future beam test.
44
Detector R&D plan
2006 : DOD
2006-2008 : Detector R&D
Budget : in Japan – applying several resources to get fund
4~5 year terms
If founded, complete detector R&D -> to prepare detector TDR
In 2006,
ACFA workshop ?
Detector workshop ?
Needs good organization …
45
Coverage in Forward region
Crucial for stau search to reduce backgrounds due to two-photon
process
Response to 10 GeV e+
EMCAL
FCAL
BCAL
No-crack now, BUT
Dead spaces has to
take into account
more seriously
Can we detect even in
huge beam-beam
background ?
cos
46