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Linear Collider Project and
Detector Concept Study
Akiya MiyamotoKEK
September, 2004
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Contents
International Linear Collider Physics Goals International activity: GDI A plan of the global experimantal program
Detector concept study Detector requirements “Huge” detector
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Role of e+e- Colliders
Historically, both pp and e+e- collider were crucial for the development of High Energy Physics
e+e- collision is an elementary process. Less background un-ambiguous measurements well defined initial state ( energy and polarization )
e+e- coliders have been and will be crucial to establish a new principle ( Lagrangian for elementary particles )
e euu d
uu d
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The Linear Collider
LEP is the last circular e+e- collider
Future e+e- are linear collider. Basic parameters of the next e+e- linear collider
Center of Mass Energy 250~1000GeV Instantaneous Luminosity 2~3x1034/cm2/s
~ 500/fb in several years 50~100k Light Higgs boson production
Total accelerator length ~30km
4~ /E E R
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Physics Goals of the Future LC
Search/Study Higgs boson(s) Spin, Mass, Branching ratios Search/study model independently
Resolve the hierarchy problem SUSY: Searches for sparticles, determine mass, spin, couplings.
Neutralino is a good candidate of the dark matter Extra-Dimensions: ee X and search virtual effects in SM processes. Other possibilities: Little Higgs Model,
Precise determination of Top quark mass and couplings TGV and Quadric gauge boson couplings key if Higgs is heavy S
Options Giga-Z collider
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A History
In Japan, LC R&D was initiated in late 1980’s. “JLC-I” report was published in 1992. It described phys
ics, detector, and accelerator of JLC. Accelerator R&D has been carried out based on warm
cavity (X/C-band) technology. In late 1990’s, ACFA Physics and detector working group
was formed. “ACFA Report” for physics and detector was published i
n 2002. “GLC project report” was published in 2003.
Reformation of Linear Collider Project under internation framework has proceed under ILCSC
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Organization chart
IUPAP
ICFA(J.Dorfan)
ITRP(2004)
(B.Barish)
GDO Taskforace(2003/2004)
(S.Ozaki)
Acc. Sub-com(G.Glow)
Parm.. Sub-com(R.Heuer)
Phys.&Det. Sub-Com(J.Brau, H.Yamamoto,
D.Miller)
ILCSC(M.Tigner)
3 regional steering com.
( Asia, N.A., Europe)
Wold Wide Study
ALCSC
ACFAPhys.&Det. WG
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International Technology Recommendation Panel (ITRP)
Warm technology (High gradiant 11GHz acc. ) has been studied by KEK/SLAC and their colleagues
Cold technology (Super Conducting Cavity ) has been studied by Tesla collab.
To realize the LC, international community should unit on a single technology for efficient use of resouces (Budget, man power, time )
Thus ILCSC organized ITRP in late 2003. ITRP met 6 times since Jan. 2004, visited 3 labs., and released recommendation in Aug. 2004.
ITRP recommends the cold technology The project is now called ILC
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GDI (Global Design Initiative)
GDI : An international rganization to develop the design of ILC. To be formed by 2005 basedon multi-lab MOU’s.
GDI schedule 2005 : Complete accelerator CDR 2006 : Initiate detailed engineering design 2007 : Complete accelerator TDR 2008 : Site selection and approval of international role a
nd responsibilities by governments. To proceed, three regional center(Asia, Europe, N.A) and the host of the central team will be setup.
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KEK’s plan Reorganization of LC accelerator R&D is under way
No decision yet Has to be defined in GDI framework
Possible contribution of KEK ( will subject ot change ) Development of Super RF cavity
Super RF cavity had been used at TRISTAN in early 90’s KEK has been provided Super RF cavity for Tesla
Injector Technologies developed at ATF will be applicable for the ILC injector
There would be more ….. ILC is the very important future project of HEP. KEK would like to keep c
ontributing the accelerator R&D. It will be the Asian regional center and may be the host of the central team.
The first ILC workshop will be held at KEK from Nov. 13 to 15.
(Personal View)
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Organizing the Global Experimental Program
GDI does not include detector studies.
Feb. 2004, the ILCSC has asked the Worldwide Study to develop a plan for organizing the experimental program in parallel with the GDI for the machine.
The WWS organizing committee and the community discussed at LCWS2004, Victoria workshop, etc anddeveloped the proposal, which was presented to the ILCSC in Aug. 2004.
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ILCSC request to WWS
This plan should include the following: 1. Ensure that at least two different detector concepts are developed;
by worldwide teams which will: - prepare CDR(s) on concepts, by ~2006; - be ready to form the cores of the collaborations when funding
is in place and bids are called for.
2. Encourage and coordinate inter-regional R&D on essential detector technologies, and give peer-reviewed recognition to nationally funded
R&D programmes as part of the worldwide project.
3. Make sure that vital questions of machine-detector interface and beamline instrumentation are as fully supported as accelerator
and detector R&D. This will involve close links with the GDI
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WWS Proposed timelineGDI Timeline
2004 – ITRP Technology Recommendation
2005 – Accelerator CDR
2007 – Accelerator TDR
2008 – LC Site Selection
Site selection + 1 year
Experimental Program
Single preliminary costing document for at least one whole-detector produced by WWS Costing Panel
CDR’s from each detector concept team (expect some individuals to sign multiple) received by the WWS OC
Collaborations form and submit LOIs for proposal to the Global Lab (or GDO?)
Global lab selects experiments and asks for TDRs (2)
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Proposed Panels Costing panel:
Request inputs from the teams studying each detector concept, ensure the same costing basis, and edit into a single document to be included with the accelerator CDR. Then the panel will stand down.
Detector R&D review panel: Maintain a register of relevant R&D, identify vital or missing
activities, arrange for peer review of proposals, and endorse approved programs to funding agencies when requested. This panel will stand down when the detector proposals are finalized.
MDI panel: Liaise with GDI to coordinate MDI issues between accelerator and
experimental teams, and ensure that essential MDI R&D is done. The panel will stand down when the global lab takes over this role.
More panels to be appointed as needed.
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WWS Proposal
WWS Organizing Committee proposes to: Recognize and coordinate studies on whole detector concepts, an
d work toward interregional detector TDRs, including a cost document available at the time of the Accelerator CDR.
Interface with GDI, especially on MDI issues. Keep a register of R&D relevant to LC experimental programs, ide
ntify those that are vital or missing, and ensure peer review of R&D proposals.
Organize interregional meetings and workshops. Report to ILCSC and ICFA on the matters above.
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Detector Concept Study
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Detector Concept Study
We started to discuss a new studies on LC detector concepts in Spring 2004 to follow the WWS proposal.
Breif presentations of the plan were presented In July at Victoria (North American LC Workshop) In September at Durham ( Europe LC Workshop )
Kick-Off meeting is scheduled at 7th ACFA workshop in Nov. 9-12 at Taipei, Taiwan. See http://hep1.phys.ntu.edu.tw/ACFA7/
A sereise of TV meetings have just started. Please join.
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Detector Requirements
Detector requirements Efficient & High purity
b/c tagging Good momentum resolution:
For Higgs detection regardless of its decay mode.
Calorimeter:For W and Z separation in hadronic decay mode.
Hermeticity:For indirect measurements of invisible particles
Good background masking and time stamping capability
GLC 3T model
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GLC 3T Model configuration
Detector parameters
Size: 8x8x6(Z) m3
Solenoid: 3TCalorimeter:
Lead./Scint. (Compensated)EM(27X0):Had(6.5l):
TrackerMain:
Small cell jet chamber(CDC)Inter Mediate Tracker
5 layers of Si.Vertex Detector
4 layers of CCD
/ ~ 15% / 1%E E E / ~ 40% / 2%E E E
4 3/ ~ 1 10 1 10 (w.VTX)Tp T Tp p
3/ 2( ) ~ 10 / sin 5IP m p
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Impact of ITRP recommendation
ITRP recommended “Cold Machine” Major Differences
Warm Machine : 150Hz pulse, each ~200 bunches with ~1.4nsec separation Event bunch ID is challenging. Enough time to read out between pulse
Cold Machine: 5Hz pulse, each ~3000 bunches with ~300nsec separation Needs to readout during the pulse
(There are many other issues such as Energy spread, crossing angle, etc. )
Implication to detector technology choice Vertex Detector : Usual CCD is too slow to readout Jet Chamber : Field distortion is not negligible Calorimeter : Will have enough time for signal integration
There are some room to improve detector design to best fit the Cold Machine
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Figure of merit : Main Tracker
samplings ofNumber :
length Tracking :
field Magnetic :
resolution Spatial : 4
7203.3/ )( 2
2
n
L
B
nBLtp
tp
The momentum resolution at lower energies is determined by multiple scattering
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Figure of merit : Calorimeter
jet2 = ch
2 + 2 + nh
2 + confusion2 + threashold
2
Separation of charged particle and /neutral hadron is important
Separation : BL2/Rm ( if consider curvature by B) L=Rin(Barrel) or Zin(End Cap), Rm=Effective Moliere length
B=0
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Merit of Huge Detector
Good Jet Energy (Particle) Flow Measurement Good charged track separation in a jet at the inner surface of the calorimeter
large BR2
Pattern recognition is easier large n with thin material,
small number of low momentum curling tracks Good momentum resolution for charged particles large BR2 √n
Good dE/dx measurement for charged particles large n
Smaller relative volume of the dead space small ΔV/V for constant ΔV
Good two track separation, Larger efficiency for Ks and Λ (any long lived) large BR2 , larger R
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“Huge Detector” model
Philosophy : Optimize for jet measurements Energy : Particle Flow Analysis – Calorimeter + Tracker
Particles should be widely separated at the Cal. Surface.Hermetic detector: Relative fraction of dead space can be made smaller
ID : Good vertex detector
Basic Design Large inner radius of ECAL (R~2m)
Large lever arm for tracker Good separation of particles at Cal. Surface
Moderate strength of magnet field: 2.5~3TCoil design : Radius is same as the GLC-3T model, but longer in Z.
To put long main tracker for good cos coverage To have enough distance from IP to the Cal. Suface.
We call “Huge” but it is still smaller than CMS at LHC
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4.85m
4.25m
5.3m
8.3m
R4m
R0.6m
4.5m
3.55m
2.35m
2.05m
0.4m
7mIron
Preliminary Mag. Field Calculation
max
02
Zmmdz
Bz
BrGoal of magnetic fielduniformity
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Detector configuration under consideration
SiVTX pixel(cold version)
HCAL(Pb(Fe)/scinti or digital)
W/Scinti ECAL
TPC(Jet chamber as option)
Si intermedi.-Trk
SC-coil
SiVTX pixel
Pb/scinti HCAL
Pb/Scinti ECAL
Jet chamber
Si intermedi.-Trk
SC-coil
“GLC” design “Huge”
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Huge
General view of “Huge”
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Area of EM CAL (Barrel + Endcap) SD: ~40 m2 / layer TESLA: ~80 m2 / layer Huge: ~100 m2 / layer (JLC-I: ~130 m2 /layer)
Huge~2.1m
Comparison of size of EM CAL surface
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SD TESLA Huge
Solenoid B(T) 5 4 3
Rin(m) 2.48 3.0 3.75
L(m) 5.8 9.2 8.4
Est(GJ) 1.4 2.3 1.2
Tracker Rmin (m) 0.2 0.36 0.40
Rmax(m) 1.25 1.62 2.05
s(mm) 7 150 150
Nsample 5 200 220
dpt/pt2 3.9e-5 1.5e-4 1.1e-4
(numbers for `Huge’ are all tentative)
A quick comparison : Tracker
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SD TESLA Huge
ECAL Rin(m) 1.27 1.68 2.1
ptmin (GeV/c) 1.9 2.0 1.9
BRin2 8.1 11.3 13.2
Type W/Si W/Si W/Scinti
RM(mm) 18 24.4 16.2
BRin2/RM 448 462 817
Z 1.72 2.83 2.8
BZ2/Rm 822 1311 1452
X0 21 24 27
Total 5.5 5.2 6.0
t (m) 1.18 1.3 1.4
A quick comparison - ECAL
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Vertex detector issues
Compared to 4T case, pair background hit at R= 15mm becomes x1.7 larger in 3T
At larger R, the background hit would decrease significantly
The configuration of R=20 mm with Si thickness < 70 m and 500 m thick beam pipe at R=12 mm still satisfies the requirement of
b=5 10/(psin3/2) m
R (mm)
B (T) Pair Background (hit/mm2/train)
15 4 1.0
15 3 1.7
24 3 0.4
TRC500 beam parameters
# of fired pixels ~ 5.0 pixels/hit
Inner radius should be optimized based on physics performance using ILC parameter
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How to reduce the ECAL cost? Which type of ECAL photo-sensor to chose? (Number of channels would be similar to other detector designs, though)
HCAL should be inside Magnet? Or can be put outside? How to support the heavy structure?
Silicon Vertex Inner radius : Background vs IP resolution need ILC parameters. Any essential impact on physics ?
Uniformity of the magnet is fine? Is structure strong enough ? Crossing-angle? Which forward detector? --> need ILC parameters
How to mechanically support central tracking system including Final-Q ?
…. …. ….
⇒Many challenges and open questions: Need detailed studies. New Participation are highly welcomed !
Questions and challenges
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Summary
We will accelerate efforts towards the ILC and experiment there. We are aiming to design a LC detector best optimized for “Particle Flo
w Algorithm”. We are now thinking to develop the “Huge” detector design.
Detailed studies have just started. There are a lot of open questions and challenges.
It will be a global efforts are we are looking for many partners in the world. Mailing list will be open soon. Please watch
http://ilcphys.kek.jp/ A kick-off meeting will be held in Taipei in Nov. 2004.