Hitoshi Yamamoto, Tohoku UniversityKIAS-CFHEP Workshop

November 13, 2015

ILC ProjectPhysics and Status

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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

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ILC : Parameters andthe Sample Running Scenario

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31 km

Damping ring

Main linac

Main linac

electron

Positron beam

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

1st Phase Baseline: 500 GeV ILC

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 5

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 e- beam: 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)

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Reference:Snowmass study

‘H20’

Total250GeV 1500fb-1350GeV 200fb-1500GeV 4000fb-1

ILC Physics Updateaccording to the sample running scenario

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HiggsTopNew ParticlesOthers+

Highlights only!

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 Couplingsmodel independent

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• 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

H20

Higgs Couplingsmodel discrimination

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• The pattern of deviation from SM tells BSM models apart

• In general, Higgs couplings needs to be measured to ~1% or better

Higgs Couplings: compare with LHCmodel dependent

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• 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)

H20

Notes on Higgs Couplings

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• 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)

kt (by e+e-→ttH): 500 GeV vs 550 GeV

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• 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

ttH cross section

top coupling error

Normalized

1 TeV Option• 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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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 at Threshold (@~350 GeV)

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Top Mass @ ThresholdTheoretical systematic error is to go down significantly for ILC, but not so for LHC

HL-LHC3000 fb-1

√s=14 TeV

ILC200 fb-1

√s=350 GeV

Stat+Sys

Stat Stat

‘H20’(sample running scenario)

Stat+Sys

Top quark mass (msbar)(@350 GeV: CLIC+ILC study)

HL-LHC3000 fb-1

√s=14 TeV

ILC100 fb-1

√s=350 GeV

Stat+Sys

Stat

Stat+Sys

Stat

Snowmass ILC500-up

Top Pair Production at 500 GeV

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Use beam polarization(separates g and Z, R and L)

Anomalous top-Z couplings

Distinguish variety of BSM models

e+e- → ttbar

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’…. 20

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Tevatron has a long list of glorious physics achievements (top discovery etc.)

For Higgs, however, it did not see clear signal even though ~20000 HiggsWere produced. Needed to wait for LHC (~1M Higgs produced in Run 1)

At ILC, only a handful of Higgs (a few tens) will do

Hadron and Lepton MachinesFNAL Tevatron

Z’ at ILC: TDR Study

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Can determine the couplings (V and A) of Z’ to leptonsBeam polarization is essential

ILC running plan: 4ab-1 at 500 GeV→ 　 error contour is half the size of the dotted line

e+e-→l+l-

Sample running scenariohas 4ab-1 at 500 GeV

An interesting Event 13 GeV LHC

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Mee = 2.9 TeVBackground ~ 0.002 If this is a Z’, then Run1 should have seen several 10’s ?

Accelerator

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• 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)

Small Emittance and Focusing

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• 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

Main Acceleration

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Kitakami Candidate Site

~50 km

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

6 drillings, 10 km each of seismic and electric surveysField survey 10 personmonth

31 km

Seismic survey

Electric survey

Geological Survey Summary

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• 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

H24-No1: core sample

DetectorsRequire unprecedented performances to fully harvest

ILC’s potential

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Impact parameter resolution

ILC

Belle ATLAS

LHCb

Alice

Jet Energy Measurement:

• Charged particles• Use trackers

• Neutral particles• Use calorimeters

• Remove double-counting of charged showers

• Requires high granularity

PFA (particle flow algorithm)

#ch ECAL HCAL

ILC (ILD) 100M 10M

LHC 76K(CMS) 10K(ATLAS)

X103 for ILCNeed new technologies !(Si pads, GEM, RPC, etc.)

ILD

Jet energy resolution ~ ½ of LHC

• 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

Two DetectorsBased on PFA idea

ILC: Political Status

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Science Council of Japan on ILC

• 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 high-energy 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.

Requested by MEXT; Report submitted on Sep 30 2013

The conclusion of the report included:

(MEXT: Ministry of education, culture, sports, science and technology)

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 Panel1. Particle&Nuclear Physics workging group

• On the ILC physics case with respect to other future projects2. TDR validation working group

• On the financial and human resources as well as maturity of design3. Newly setup: Human resources working group

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MEXT on the ILC

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ILC Taskforce

ILC Advisory Panel

Particle&nuclear physcis working group

TDR validation working group

MEXTScience Council of

Japan

RecommendationSep 30, 2013

MEXT: Ministry of education, culture, sports, science and technology

Academic Experts Committee Interim Summary

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‘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.’

On the scientific merit of the ILC

June 25, 2015

Three Recommendations

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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)

Letter from ICFA to ILC Advisory Panel

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27 August 2015

The chair of the International Linear Collider Advisory PanelProfessor 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 MnichDESY Research DirectorChair of ICFA

ILC Advisory PanelShinichi Hirano

ICFA ChairJoachim Mnich

JS-Japan Parliamentary Coorperation

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) 42

US-Japan alliance and cooperation onadvanced science and critical technologies

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 　　　

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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

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

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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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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’

US : P5 Report (May 23, 2014)

P5 chair, Steven RitzSCIPP director, UCSC

(Particle Physics Projects Prioritization Panel)

LINEAR COLLIDER COLLABORATIONDesigning the world’s next great particle accelerator

Underground Facilities around the Detector Hall

From the EDMS Meeting @KEK 2.12.2014

Assembly Hall

Main Shaft

Utility Shaft

Damping Ring

BDS

Access Portal

Detector Hall

Access Tunnel

3D Design Integration model: Underground and Surface Facilities

Bird’s-eye view image of the Underground Facilities at IR

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Utility Cavern

Utility Building