**** 1 - Indico

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**** 1 - Indico
ILC Project
Hitoshi Yamamoto
Tohoku University
INSTR2014
Novosibirsk, February23, 2014
ILC (International Linear Collider)
e+ e- collider
 500 GeV CM with 31 km → upgrade later to ~ 1TeV CM with 50 km
 IP beam size : 6 nm high, 500 nm wide 300 mm long (@500 GeV CM)
 Luminosity 1.8 x 1034 /cm2s (@500 GeV CM)
 First stage : 250 GeV Higgs Factory
F
ILC TDR Completion
June 12, 2013
‘A World-wide Event – from design to reality’
Fermilab
Tokyo
CERN
New International LC Organization
LC Board
LCC (LC Collaboration)
Chair : Sachio Komamiya
Deputy Director
LC Collaboration Director
Hitoshi Murayama
Lyn Evans
ILC accelerator
CLIC accelerator
ILC/CLIC Phys./Det.
Mike Harrison
Steinar Stapnes
Hitoshi Yamamoto
In full operation since June, 2013
4
ILC Timeline
by LCC
• 2013 - 2016
– Negotiations among governments
– Accelerator detailed design, R&Ds for cost-effective production, site
study, CFS designs etc.
– Prepare for the international lab.
• 2016 – 2018
–
–
–
–
‘Green-sign’ for the ILC construction to be given (in early 2016 )
International agreement reached to go ahead with the ILC
Formation of the ILC lab.
Preparation for biddings etc.
• 2018
– Construction start (9 yrs)
• 2027
– Construction (500 GeV) complete, (and commissioning start)
(250 GeV is slightly shorter)
ILC Physics
ILC features : cleanliness
■
Collision of two elementary particles

proton + proton at LHC


quark
Proton = 3 quarks + gluons
electron + positron at ILC
→ Signal is clearly seen without much noises
gluon
proton
proton
ILC
→ Trigger-less data taking
→ Theoretically clean
(less theoretical uncertainties)
LHC
LHC
electron
ILC
All from Higgs
positron
ILC features : control
■
Initial state of electron-positron interaction :


Energy-momentum 4-vector is specified
Electron polarization (80%~90%) is specified

Positron polarization (60%) is optional (30% comes for free)
Energy-momentum 4-vector
→ e.g. recoil mass analysis: tagged Higgs
Higgs to ALL (including invisible final state)
ILC
LHC
H⇾gg
H⇾ZZ
Electron polarization
Specify the intermediate state

e.g. Right-handed e- turns off A0

e+
g,Z
Information on the gauge structure
of the final state
(B,A0)
Increase rates

e.g. P- /P+ = -0.8/+0.3 :
Increases the H production mode
s(nnH) by X 2.34 (=1.8 x1.3 )
ee+
W+
e-
W-
Background rejection

Right-handed e- turns off W
e.g. acoplanar muon pair produciton
such as smuon pair production
ILC @1 TeV
Higgsstrahlung
W fusion
Higgs production
Luminosity
each energy for ~3 years
• At higher Ecm
– W fusion dominant
– More Higgs
– New particles !
• Good for Higgs self coupling
e+e- ⇾ nnHH
– Effect of irreducible diagrams less important
dl/l = 0.76 ds/s @ 1 TeV
(dl/l = 1.66 ds/s @500 GeV)
 dl/l = 13% (2.5 ab-1 @ 1 TeV)
Higgs Reconstruction
At 250 GeV
Recoil mass analysis
dMH = 32 MeV
(TDR)
At 500 GeV
2 jet + nothing
Main background = nnZ
ILC Luminosity Upgrade Options
• 250 GeV CM (Higgs factory)
– X4 luminosity @ 3E34/cm2s
– x2 Nbunch, x2 rep rate; 120 ⇾ 200 MW wall plug
• 500 GeV CM
– x2 luminosity @3.6E34/cm2s
– x2 Nbunch; 160 ⇾ 200 MW wall plug
• 1 TeV CM
– x1.4 luminosity @5E34/cm2s
– Aggressive beam params;
Same wall plug power
Measurement errors of Higgs Couplings
(Snowmass study – Higgs WG)
• All assume generation universality, no BSM → Fit
– LHC ranges : optimistic (sys.err: theory = 1/2, exp. N-1/2), pessimistic (no change)
• Apart from g, ILC is 1/3 ~ 1/10 of HL-LHC (w/o ILC lum upgarde)
• With ILC lum upgrade, additional ~1/2 in errors
• ILC can measure model-independently w/o assumptions above.
Top Yukawa Coupling
Not a mode ILC is partifcularly good at
Direct measurements
Higgs Width and CP
• Gtot to 5%
– Br(H ⇾ WW) & g(HWW) by e+e- ⇾ nnH
– Br(H ⇾ ZZ) & g(HZZ) by e+e- ⇾ HZ
• CP
– 3~4% (on mixing coeff) by HZ
• cross sestion and production/decay angles
– Or by H → tt (t polarization)
• a to 6゜ w/ ab-1 at 350 GeV
Top
mt(msbar) to 100 MeV
Sensitivity to ttH coupling at threshold
Anomalous ttZ, tbW, ttg coup
New Particle Search
ILC
Good sensitivity up to kinematic limit for
(essentially) any mass difference
LHC
Difficulty when mass difference is small
Fermion Compositeness
ILC 500 GeV : e+ e- → ff
+ - : initial helicity
Z’ couplings to identify a model
e+ e- → l+lMZ’ = 2 TeV
1000 fb-1 at 500 GeV
P- = 0.8, P+ = 0.6
MZ’ = 4 TeV
Dark Matter
■
■
■
Lightest super particle (LSP) is the dark matter?
Key: can the theory with measured parameters explain the
‘measured’ relic density?
Creation and annihilation → relic density
•
Need to know processes contributing to LSP annihilation
Relic density estimation by
LHC (red) and ILC(blue)
(SUSY B’ model)
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ILC Accelerator
ILC: How it works
Produce:electron source
Align:damping ring
Focus:final focus System
Detect:high-res detectors
Accelerate:main linac
Produce:Positron source
Align and Focus
• Low emittance : KEK ATF (Accelerator
Test Facility)
– Achieved the ILC goal.
• Small vertical beam size : KEK ATF2
– Goal = 37 nm, 65 nm achieved
• Limit is in measurement. No basic problem seen.
• Stabilize the beam at nm scale: KEK ATF2
– Feedback system successful (FONT)
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Accelerate : Main LINAC
• Principle of acceleration
– Generate strong RF wave in a
cavity
– Synchronize such that particle
is always accelerated forward
• ILC accelerating cavity
–
–
–
–
Superconducting (niobium)
1.3 GHz (L band)
9 cell, 1 m
Accelerting gradient
• Average 31.5 MV/m
• 250 GeV/31.5 MeV = 8000
cavities needed → 8km
(In reality 11 km/side)
超電導加速空洞 (Ichiro cavity)
1m
Main LINAC Achievements
• Accelerating cavity
– Spec: 31.5 MV/m ±(<20%)
– >80% yield achieved (RDR goal achieved)
• Cryomodule assembly
– Combine cavities from all over the world
• KEK S1-global successful
ILC technology is now ‘ready’
25
Status of the ILC
Mostly in Japan
International Supports
• Europe : ‘European Strategy’ (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.
• US : HEPAP facilities subpanel report (March 22, 2013)
– The initiative from the Japanese particle physics community to host the
ILC in Japan is very welcome, and the U.S. particle physics community
looks forward to a proposal from Japan to discuss possible participation.
– For the final US strategy, wait for the HEPAP subpanel (P5) report
(March-May, 2014)
27
Political support :
LDP
(Liberal Democratic Party : New Ruling Party)
election platform
‘ILC’ appears twice explicitly
32 Rebuilding true command tower functions that strongly advance
science and technology policies
– …We will actively promote the critical fields of energy creation, energy
conservation, energy storage, etc. as knowledge-concentrated national
strategies - for example, our country should be able to play a leading role
in creation of international centers for scientific innovations such as the
ILC (the international linear collider) project which is a grand project in the
field of particle physics.
92 Creation of globally top-class centers for research and development
– …We will significantly strengthen supports for universities and public
research facilities that perform studies at levels above the intentional
standards, such as significant expansion of WPIs and playing a leading
role in creation of international centers for scientific innovations such as
the ILC (the international linear collider construction) project which is a
grand project in the field of particle physics.
28
Press conference by
the MEXT minister Shimomura
Jan 18, 2013
‘(On ILC) We would like to consider the
plan for the near future, while as the
government actively negotiating with
relevant countries in the first half of this
year … we are now studying the legal
framework.’
The Japanese government did start to talk to other governments.
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Science Council of Japan
Report submitted : Sep 30, 2013
(Official translation)
•
•
•
…the Committee appreciates the need for and scientific significance of an
electron-positron collider as a unique complement to the proton-proton
collider.
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.
MEXT has requested ~$0.5M for the investigatory study
which was approved on Dec 24, 2013
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A Letter to the DOE Secretary from
the Federation of Diet Members for the ILC
(~160 out of ~700 diet members total)
Jan 8, 2014
…
In Japan, for the first time ever, the government has allocated a budget for
the coming Japanese fiscal year to investigate and examine the ILC itself…
This has great significance in that the Japanese government has shown a
vital interest in the ILC project.
…
The ultimate decision to host the ILC project rests with the Japanese
government and the Diet. Both houses of the Diet are strongly in support of
the ILC project.
We have reached the stage where we must now work together with the
other government for the realization of the ILC. The Japanese government
intends to perform concentrated investigations and address the major issues
and arrive at a conclusion about hosting the ILC by the end of JFY 2015.
31
The most important issue for the realization of the ILC is whether it can
become a truly global project. For this purpose, the Japanese government is
currently gathering information from abroad and is starting talks with the
United States and European countries about forming a partnership.
…
All 3 have served as the
MEXT minister
32
ILC Candidate Sites in Japan
Kitakami
• Kyushu
– Sefuri mountains
• Tohoku
– Kitakami mountains
‘ILC site evaluation committee’ (JAHEP)
Co-chairs: Kawagoe, Yamamoto
evaluated them based on
1. Geology and other technical aspects
2. Socio-economic conditions
Selected the Tohoku Site (Aug 23, 2013)
Sefuri
Kitakami Site
•
•
•
•
Flexibility in positioning the 50 km route
Shorter access tunnels
Natural Drainage
etc…
Oshu-city
Ichinoseki-city
Sendai
34
Kesennuma-city
Summary
• With the discovery of Higgs, the physics case for the ILC is now
stronger than ever
• ILC accelerator design is ‘ready’ with the completion of TDR
• The ILC detectors are pushing the state of the art of particle
detection technologies
• Japanese government is now negotiating with other governments
toward realization of a truly global ILC lab
• There are strong supports from the international scientific
community. (will they translate to real commitments?)
35
Sefuri Site
ILC route vertical cross section
Kitakami
~100m above sea level
Sefuri
Matsuura River
Below sea level
0.5% tilt

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