Hitoshi Yamamoto, Tohoku University
KIAS-CFHEP Workshop
November 13, 2015
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Plan of talk
• ILC parameters and the sample running scenario
• Physics updates according to the sample running
scenario
• Accelerator
• Detectors
• Political status
2
ILC : Parameters and
the Sample Running Scenario
3
1st Phase Baseline: 500 GeV ILC
 Ecm = 500 GeV, L = 1.8 x 1034 /cm2s
 Polarization (e+/e-) = ±0.3/±0.8
 2x1010 particles/bunch, 1312 bunch/train, 5 trains/sec
 Beam size at IP : sy = 5.9nm, sx = 474nm, sz = 300mm
 Average accelerating gradient = 31.5 MV/m
 Wall plug power = 163 MW
4
ILC at Lower Energies
(The baseline 500 GeV machine running at lower energies)
• 250 GeV CM
•
•
•
•
Average accelerating gradient = 14.7 MV/m
Wall plug power = 122 MW
L = 0.75 x 1034 /cm2s
Run the linac at 10 Hz, alternate e+ production and
luminosity (150 GeV e- beam is required to produce
enough e+’s)
• 350 GeV CM
• Average accelerating gradient = 21.4 MV/m
• Wall plug power = 121 MW
• L = 1.0 x 1034 /cm2s
Bunch population/pattern, polarizations are the same
as for the baseline 500 GeV
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ILC Luminosity Upgrades
• 250 GeV CM
• X4 luminosity @ 3E34/cm2s
• x2 Nbunch, x2 rep rate (10Hz); 122 ⇾ 200 MW wall plug
• Use a longer undulator to produce enough e+’s by 125 GeV ebeam: no need to alternate e+ production and luminosity
• 500 GeV CM
• x2 luminosity @3.6E34/cm2s
• x2 Nbunch; 163 ⇾ 204 MW wall plug
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ILC Running Scenario
• Ability to run at various energies: a merit of the ILC
• Can the stated luminosities at different energies be taken in a
reasonable total running time?
• Realistic ramp up profiles and down time for upgrade should
also be taken into account
→ ‘Standard sample running scenario’ for up to 500 GeV to run
for ~20 years total (ref: ~25 years for LHC)
Actual running scenario will depend on physics outcomes from
LHC and ILC, and other factors
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Standard Sample ILC Running Scenario
• After examining various scenarios, one scenario (H20) was recommended by
the ILC parameters WG and approved by the LCB (Linear Collider Board)
Total
250GeV 1500fb-1
350GeV 200fb-1
500GeV 4000fb-1
‘H20’
Reference:
Snowmass study
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ILC Physics Update
according to the sample running scenario
Higgs
Top
New Particles
Others+
Highlights only!
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Two documents:
• ‘ILC Operating Scenarios’
• By the ILC parameters Working Group of LCC
• arXiv:1506.07830
• ‘Physics Case for the International Linear Collider’
• By the Physics Working Group of LCC
• arXiv:1506.05992
Both are found at http://www.linearcollider.org/P-D/Documents
‘Standard references’
Higgs Couplings
model independent
H20
• No assumption for generation universality, unitarity, nor on BSM.
• Absolute measurements of decay rates
• Apart from g, t, m, accuracy is ~1 % or less
• Level that is meaningful in distinguishing models
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Higgs Couplings
model discrimination
• The pattern of deviation from SM tells BSM models apart
• In general, Higgs couplings needs to be measured to ~1% or
better
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Higgs Couplings: compare with LHC
model dependent
H20
• All assume generation universality, no BSM → Fit : model-dependent
• CMS-1: HL-LHC pessimistic (sys err : no change)
• CMS-2: HL-LHC optimistic (sys.err : theory = 1/2, exp. N-1/2)
• Apart from g, ILC (H20) is 1/5 ~ 1/15 of HL-LHC
• Statistical power of ILC: ~100 HL-LHC running simultaneously
ILC is for 1IP, HL-LHC is for CMS only
• If CMS and ATLAS are combined, error would decrease (1/sqrt2 if stat-dominated,
~no decrease if sys-dominated)
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Notes on Higgs Couplings
• For kZ and kW , production rates give high precision
• e+e- → ZH for kZ and e+e- → nnH for kW [with Br(H→bb)]
• In general for kX , Gtot is necessary in addition to Br(H→x)
• Gtot = Br(H→ZZ)/G(H→ZZ) with G(H→ZZ) from kZ
• Gtot = Br(H→WW)/G(H→WW) with G(H→WW) from kW
• W mode is far more powerful: 350 GeV or higher running is
necessary to fully make use of ILC capability
• For kg , LHC and ILC are combined
• Br(H→gg)/Br(H→ZZ) by LHC and kZ by ILC
• Physics: Higgs self coupling
• 1TeV: 16% with 2000 fb-1, 10% with 5000 fb-1
• 500 GeV: 27 % with 4000 fb-1 (H20)
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kt (by e+e-→ttH): 500 GeV vs 550 GeV
ttH cross section
top coupling error
Normalized
• e+e- → ttH cross section increases by nearly x4 by 500 GeV →550 GeV
→ kt error reduces by ½ (6% to 3%)
by running at 550 GeV instead of 500 GeV
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• Extend the total length to ~50 km
• Add 45 MV/m cavities (keep the old ones)
• Average accelerating gradient = 38.2 MV/m
• Wall plug power = 300 MW
• Beam size at IP : sy = 2.8 nm, sx = 481 nm, sz = 250 mm
• Smaller by the boost
• 2450 bunches/train, 4 trains/s
• L = 3.6 x 1034 /cm2s
• Upgrade: x1.4 luminosity @4.9E34/cm2s
• Aggressive beam parameters: smaller sx and sz
Same wall plug power (300 MW)
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Top at Threshold (@~350 GeV)
Threshold scan determines Re(pole) to 50 MeV (mostly theoretical)
The msbar top mass can be obtained from Re(pole) with 10 MeV
theoretical uncertainty
Theoretical uncertainties will improve over time
Bonus: Sensitivity to ttH coupling at threshold (vertex correction)
Top Mass @ Threshold
Top quark mass (msbar)
(@350 GeV: CLIC+ILC study)
Snowmass ILC500-up
Theoretical systematic error is to
go down significantly for ILC, but
not so for LHC
‘H20’(sample running scenario)
Stat+Sys
Stat+Sys
Stat+Sys
Stat
Stat
ILC
HL-LHC
-1
100 fb-1
3000 fb
√s=14 TeV √s=350 GeV
Stat
Stat+Sys
Stat
ILC
HL-LHC
200 fb-1
3000 fb-1
√s=14 TeV √s=350 GeV
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Top Pair Production at 500 GeV
e+e- → ttbar
Anomalous top-Z couplings
Distinguish variety of BSM models
Use beam polarization
(separates g and Z, R and L)
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New Particle Search
LHC:
Difficulty when mass difference is small
ILC:
Good sensitivity up to kinematic limit for
(essentially) any mass difference
In general:
LHC can reach higher energy but could miss important phenomena
‘Other than special contrived cases, LHC would find it if it is there’ – true?
Apart from the fact that near degeneracy cases are quite ‘natural’….
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Hadron and Lepton Machines
FNAL Tevatron
Tevatron has a long list of glorious physics achievements (top discovery etc.)
For Higgs, however, it did not see clear signal even though ~20000 Higgs
Were produced. Needed to wait for LHC (~1M Higgs produced in Run 1)
At ILC, only a handful of Higgs (a few tens) will do
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Z’ at ILC: TDR Study
e+e-→l+l-
Sample running scenario
has 4ab-1 at 500 GeV
e
Can determine the couplings (V and A) of Z’ to leptons
Beam polarization is essential
ILC running plan: 4ab-1 at 500 GeV
→ error contour is half the size of the dotted line
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An interesting Event 13 GeV LHC
Mee = 2.9 TeV
Background ~ 0.002
If this is a Z’, then Run1 should have seen several 10’s ?
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Accelerator
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Small Emittance and Focusing
• Low emittance : KEK ATF (Accelerator Test
Facility)
• Achieved the ILC goal.
• Small vertical beam size : KEK ATF2
• Goal = 37 nm, 44 nm achieved
• No basic problem seen.
• Stabilize the beam at nm scale: KEK ATF2
• Feedback system successful (FONT)
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Main Acceleration
• Accelerating cavity
• Spec: 31.5 MV/m ±(<20%)
• >80% yield (RDR goal achieved)
• Cryomodule assembly
• Combine cavities from all over the world
• KEK S1-global successful
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Kitakami Candidate Site
Now the only candidate site for which studies are being made
• 50 km line can be taken with flexibility
• Access tunnels can be reasonably short (mild terrain)
• Natural drainage to nearby rivers is possible
• Vertical shaft to detector hall can be used
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Vertical Access to Detector Hall
• TDR baseline for Asian site: horizontal
access
• Difficult to transport heavy and large pieces
• Vertical access (~ 90 m depth)
• Large piece can be assembled on surface
and then lowered by a gantry crane
• Merit of vertical access
• Detector can be assembled while detector
hall is dug and equipped
• Cost and time
• Construction time is reduced by ~1 year
• Cost is likely to be reduced
Vertical access: Adopted as new baseline
（LCC Change Management Process)
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Geological Surveys
Seismic survey
Electric survey
31 km
6 drillings, 10 km each of seismic and electric surveys
Field survey 10 personmonth
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H24-No1: core sample
Geological Survey Summary
• Some erosions near surface
• It seems that there is a solid granite
bedrock at the beam line
• There are locations with deep heat
erosions
• Overall no serious problems are
found
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Detectors
Require unprecedented performances to fully harvest
ILC’s potential
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Impact parameter resolution
Alice
Belle
ATLAS
LHCb
ILC
PFA
(particle flow algorithm)
Jet Energy Measurement:
• Charged particles
• Use trackers
• Neutral particles
• Use calorimeters
• Remove double-counting of
charged showers
• Requires high granularity
ILD
#ch
ECAL
HCAL
ILC (ILD)
100M
10M
LHC
76K(CMS)
10K(ATLAS)
Jet energy resolution ~ ½ of LHC
X103 for ILC
Need new technologies !
(Si pads, GEM, RPC, etc.)
Two Detectors
Based on PFA idea
• SiD
• High B field (5 Tesla)
• Small ECAL ID
• Small calorimeter volume
• Finer ECAL granularity
• Silicon main tracker
• ILD
• Medium B field (3.5 Tesla)
• Large ECAL ID
• Particle separation for PFA
• TPC for main tracker
ILC: Political Status
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Science Council of Japan on ILC
Requested by MEXT; Report submitted on Sep 30 2013
(MEXT: Ministry of education, culture, sports, science and technology)
The conclusion of the report included:
• The Committee suggests that the government of Japan should (1) secure
the budget required for the investigation of various issues to determine the
possibility of hosting the ILC, and (2) conduct intensive studies and
discussions among stakeholders, including authorities from outside highenergy physics as well as the government bodies involved for the next two
to three years.
• In parallel, it is necessary to have discussions with the research institutes
and the responsible funding authorities of key countries and regions
involved outside of Japan, and to obtain clear understanding of the
expected sharing of the financial burden.
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MEXT ILC Advisory Panel
• MEXT has requested and obtained $0.5M/year for
investigatory study in 2014 and 2015. $1M requested for 2016
• ‘ILC Advisory Panel’ was established under MEXT (Early 2014)
• Report to be completed by FY2015 (i.e. end of March 2016) (even
though extendable)
• Two+1 working groups under the ILC Advisory Panel
1. Particle&Nuclear Physics workging group
•
On the ILC physics case with respect to other future projects
2. TDR validation working group
•
On the financial and human resources as well as maturity of design
3. Newly setup: Human resources working group
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MEXT on the ILC
MEXT: Ministry of education, culture, sports, science and technology
Science
Council of
Japan
Recommendation
Sep 30, 2013
MEXT
ILC Taskforce
ILC Advisory Panel
Particle&nuclear physcis
working group
TDR validation working
group
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Academic Experts Committee Interim Summary
June 25, 2015
On the scientific merit of the ILC
‘The ILC is considered to be important because of its capability to
investigate new physics beyond the Standard Model by exploring new
particles and precisely measuring the Higgs boson and top quark. It should
be also noted that the ILC might be able to discover a new particles which
are difficult to be detected in LHC experiments.’
‘ILC experiments are able to search for new particles, different from the
ones that LHC experiments have been searching for. In case these new
particles are supersymmetric particles, ILC and LHC experiments can study
them complementally. On the other hand ILC experiments can carry out
more precise measurement of the Higgs boson and the top quark, which are
beyond the reach of LHC experiments.’
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Three Recommendations
Recommendation 1: The ILC project requires huge investment that is so huge
that a single country cannot cover, thus it is indispensable to share the cost
internationally. From the viewpoint that the huge investments in new science
projects must be weighed based upon the scientific merit of the project, a clear
vision on the discovery potential of new particles as well as that of precision
measurements of the Higgs boson and the top quark has to be shown so as to
bring about novel development that goes beyond the Standard Model of the
particle physics.
Recommendation 2: Since the specifications of the performance and the
scientific achievements of the ILC are considered to be designed based on the
results of LHC experiments, which are planned to be executed through the end
of 2017, it is necessary to closely monitor, analyze and examine the
development of LHC experiments. Furthermore, it is necessary to clarify how to
solve technical issues and how to mitigate cost risk associated with the project.
Recommendation 3: While presenting the total project plan, including not only
the plan for the accelerator and related facilities but also the plan for other
infrastructure as well as efforts pointed out in Recommendations 1 & 2, it is
important to have general understanding on the project by the public and science
communities.
(These recommendations are issues for MEXT still to investigate)
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Letter from ICFA to ILC Advisory Panel
27 August 2015
The chair of the International Linear Collider Advisory Panel
Professor Shinichi Hirano
Dear Professor Hirano:
At its recent meeting, the International Committee for Future Accelerator ICFA(1) composed of directors of
leading international particle physics laboratories and representatives of the word-wide particle physics
community, discussed the document “Summary of the International Linear Collider (ILC) Advisory Panel’s
Discussion to Date” produced by your panel. ICFA thanks you for the significant effort by you and the panel to
study the ILC and its possible realization in Japan. We appreciate your very important summary document
which indicates the serious interest of Japan in hosting a linear collider and which we take as an
encouragement for the work of the worldwide ILC community.
ICFA is preparing a short document to clarify some of the issues and questions raised in your summary. The
document will be submitted to your panel before the end of this year. We would be pleased to assist in
obtaining further information in case the need arises in the course of your investigation.
Sincerely
Joachim Mnich
DESY Research Director
Chair of ICFA
ICFA Chair
Joachim Mnich
ILC Advisory Panel
Shinichi Hirano
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JS-Japan Parliamentary Coorperation
US-Japan alliance and cooperation on
advanced science and critical technologies
4 areas:
• Existing large-scale projects:
• Space (ISS, GPS etc.)
• Nuclear energy (fuel cycle, plasma technology)
• New areas
• Advanced accelerators (ILC and applications)
• Next-generation supercomputing
• Preparations are on-going
• April 2015:
• Two ex MEXT ministers et al. met with key members of the US government and
both houses
• Collaborative work for ILC between AAA（Advanced Accelerator Association
promoting science and technology of Japan) and Hudson Institute has begun
• Diet members from Japan will visit Washington DC next Jan. to initiate a
formal framework of cooperation (US-Japan Parliamentary Friendship
League and Federation of Diet Members for the ILC)
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JS-Japan agreement on HEP
• Caroline Kennedy’s twitter: ‘US & Japan sign project agreement to advance
cooperative research in high energy physics. ’
• This overwrites the current US-Japan agreement on HEP
DOE: Jim Siegrist
KEKDG Masa Yamauchi
One item: Key Accelerator Technologies, including
•
•
•
•
Linear Collider Technologies
High Intensity/Luminosity Accelerator Technologies
Superconducting Accelerator Technologies, and
Advanced Accelerator Technologies
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Summary
• ILC’s cleanliness and control lead to significantly extended
discovery potential for new physics wrt HL-LHC.
• When any new particle is within kinematic reach, ILC can
find it in most cases, and figure out the structure of the new
physics. (ILC is good at unpredicted phenomena!)
• The ILC technology is now ready and site-specific designs
are accelerating
• Political supports are strong both domestically and
internationally.
• Japanese government is seriously evaluating cases for the
ILC, and in parallel, initiating high-level contacts with other
countries
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Backup
45
MEXT Minister US Visit
• January 10, 2014
• MEXT minister Shimomura visited US and met with DOE secretary E. Moniz
• Facebook of MEXT Minister
• ‘Visited Moniz DOE director, and discussed about the ILC etc.’(mentioned
explicitly only about the ILC)
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European Strategy
• Issued on March 22, 2013
• There is a strong scientific case for an electron-positron collider,
complementary to the LHC, that can study the properties of the Higgs
boson and other particles with unprecedented precision and whose
energy can be upgraded … The initiative from the Japanese particle
physics community to host the ILC in Japan is most welcome, and
European groups are eager to participate. Europe looks forward to a
proposal from Japan to discuss a possible participation.
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US : P5 Report (May 23, 2014)
(Particle Physics Projects Prioritization Panel)
On the scientific case of the ILC
‘we emphasize most strongly that the scientific justification for the
project is compelling’
On the US participation in the ILC
‘As the physics case is extremely strong, all Scenarios include ILC
support at some level through a decision point within the next 5 years’
‘Unconstrained budget’ (Scenario C)：‘Play a world-leading role in the
ILC experimental program and provide critical expertise and
components to the accelerator, should this exciting scientific
opportunity be realized in Japan’
P5 chair, Steven Ritz
SCIPP director, UCSC
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LINEAR COLLIDER COLLABORATION
Designing the world’s next great particle accelerator
Underground Facilities around the Detector Hall
Bird’s-eye view image of the
Underground Facilities at IR
Assembly Hall
Utility Building
Access Portal
Utility Shaft
Main Shaft
Utility Cavern
Detector Hall
3D Design Integration model:
Underground and Surface Facilities
From the EDMS Meeting @KEK 2.12.2014
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