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XXI DAE-BRNS High Energy Physics Symposium 2014 School of Science, and ICEPP, the University of Tokyo Chair: High Energy Physics Committee of Japan Sachio Komamiya

Particle Physics beyond the Standard Model and the ILC Project

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For more than 20 years, we keep agitating that a Revolution in the field of particle physics is inevitable. ⇒ 4th July 2012 : Discovery of “Higgs Boson” The July revolution has started

⇒ We hope it is just a start of an enormous revolutionary era overwhelming the Standard Model = the Ancien Regime.

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The Discovery of a Higgs Boson 4th July 2012 The July Revolution

Supersymmetry explains the EW symmetry breaking (μ2<0) with an elementary Higgs scalar Discovery of SUSY particles is expected

Higgs Boson is elementary

Higgs Boson is composite

A Big Branching is ahead of us Although Higgs was discovered , we do not know the origin of Electro-weak symmetry breaking.

Higgs Boson is a firmly bound state of more elementary particles by a new QCD like strong interaction which causes vacuum condensation More bound states are expected In the TeV mass region

e

e +

-

Z

Ｚ

H bb

μ＋μ-

-

Electron-positron collider Electron and positrons are point-like elementary particles

No forward jets. 4-momrntum conservation can be used ⇒ Clean environment Process is simple ⇒ Prediction： O(0.1-1%)

p

p

bb -

g

g

t

Proton-Proton Collider

H

hadrons

hadrons

Proton is a composite particle ⇒ Complicated process NNLO O(10%)

High radiation High event rate

⇒ need a high tech detector + smart physicists

pp-collision ｖｓ e+e− collision 5

Limitation on High Energy Circular e+e- Colliders

Reaction is simple, experiment is clean but… Electrons and positrons loose energy due to synchrotron radiation

Energy loss per trun ΔE is given by

ΔE ∝ （E/m）４/R

E：particle energy ｍ：particle mass R：radius

Like a bankruptcy by loan interest

E, m

Recover the energy loss and obtain higher collision energy

（１）Use heavier particle (proton mass/electron mass＝1800）⇒ LHC

（２） Larger radius ⇒ LEP(27 km) ⇒ large radius

２Ｒ

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Linear Electron Positron Collider is inevitable

Straight beam line ⇒ No synchrotron radiation （Linear Collider）

e+ e-

Electrons are accelerated from one side positon from the other side. Collide the beams at the center

Reduce construction cost ⇒ High acceleration gradient

Reduce running cost (electric power) ⇒ Squeeze the beam size as small as possible at the interaction point ⇒ round beam is unstable ⇒ very flat beam

Large radius R ⇒ Ultimate radius R=∞ ！

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ILC in a nutshell

Stands for: International Linear Collider Collides: electrons and positrons CM energy: 250-500 GeV (baseline); ~1 TeV upgrade option Length: 31 km @ 500 GeV extend for higher energy

Beam polarization: P(e-,e+) = (±80%, ±30%) Most mature accelerator design for e+e- collisions.

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9

5.1 km 1.1

km

Main Linac

2.2 km 1.3

km

BDS e+ s

rc

IP

central region

15.4 km

5.1 km 1.1

km

Main Linac

bunc

h co

mp.

2.2 km 1.3

km

BDS e+ s

rc

IP

central region

15.4 km

125 GeV transport

Advantages of linear collider (1) No energy loss due to synchrotron radiation

(2) Extendability (length ⇒energy ) (3) Beam Polarization

FNAL

NML facility ILC RF unit test Under construction

DESY

TTF/FLASH (DESY) ~1 GeV ILC-like beam ILC RF unit (* lower gradient) STF (KEK) operation/construction

ILC RF unit test

KEK, Japan Cornell

CesrTA (Cornell) electron cloud low emittance

INFN Frascati

DAfNE (INFN Frascati) kicker development electron cloud

ATF & ATF2 (KEK) ultra-low emittance Final Focus optics KEKB electron-cloud

Accelerator R&D

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SCRF R&D India, China

DESY Euro-XFEL SLAC SCLS XFEL

Key Technologies of ILC (ILC-TDR)

Superconducting RF Cavities Average of three regions

Nanometer-sized beams ATF2 at KEK

Yield: 94% at >28 MV/m Average: 37.1 MV/m (Target: 31.5 MV/m) ⇒Industrialization

Achieved: 44 ± 3 nm @ 1.3 GeV (June 2014) (Target beam size: 37 nm, Equivalent to 5 nm @ 250 GeV) 11

Higgs Physics at ILC

e

e +

-

Z

Ｚ

H Ｘ

μ+μ－

ILC μ+μ－recoil mass distribution

p

p

g

g

t

LHC H→γγ mass distribution

H

hadrons

hadrons

γγ

Two measurements are complementary and qualitatively different

Higgs Boson 250-500 GeV ILC is the Higgs Boson Factory O(10 ) Higgs events will be produced and studied. Origin of mass Structure of the ‘vacuum`.

Precise measurement of Higgs Boson ⇒Deduce Principal Low in the Nature

e e Z + H e e + b b - + + - -

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ZH dominates at 250 GeV (~80k ev: 250 fb-1)

vvH takes over at 500 GeV (~125k ev: 500 fb-1)

Production cross section

Rediscovery of Higgs in one day of running

Higgs Production at ILC

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Higgs Coupling Model-independent determination: unique at ILC

~1% precision for most couplings

Top Yukawa improves by going to 550 GeV Near threshold → factor ~4 enhancement of σtth by 500 GeV 550 GeV

LHC can precisely measure BR(h→γγ)/BR(h→ZZ*)

= (Kγ / KZ)2

ILC can precisely measure KZ

Better hγγ with LHC/ILC synergy!

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Excellent vertex resolution for b/c separation

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Fingerprinting

Supersymmetry (MSSM)

Composite Higgs (MCHM5)

Higgs boson: elementary or composite?

ILC 250+500 LumiUp

Able to distinguish models with specific patterns 18

Fingerprinting

Supersymmetry (MSSM)

Composite Higgs (MCHM5)

Higgs boson: elementary or composite?

ILC 250+550 LumiUp

Able to distinguish models with specific patterns 19

Higgs Self-Coupling

H

H

H

H

Ongoing analysis improvements towards O(10)% measurement

Challenging measurement due to: • Small cross section (~0.2 fb) • Many jets in the final state • Irreducible background diagrams

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Confirm whether or not V(ϕ)=μ2ϕ2/2+λϕ4/4

is a good starting point

✔ Existence of HHH coupling is evidence of vacuum condensation

✔

4000 fb-1

18 %

29% (500 GeV) 11% (500 GeV+1TeV)

18 % 18 % 18 %

Example: Electroweak baryogenesis in a Two Higgs Doublet Model Large deviations in Higgs self-coupling → 1st order EW phase

transition → Out of equilibrium

+ CPV in Higgs sector → EW baryogenesis possible

Region where EW baryogenesis is expected

Minimum value of Higgs self-coupling for EW baryogenesis

Senaha, Kanemura

ILC can test the idea of baryogenesis occurring at the electroweak scale.

1st order EWPT

Electroweak Baryogenesis

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Top Physics at ILC

Vacuum Stability in the SM

Does λ really become negative below ΛPl?

or λ(ΛPl) = 0?

arXiv:1205.6497, Degrassi et al.

mH=125GeV SM

vacuum appears to be at a subtle point of meta-stability

Top Pair Threshold ~350 GeV

ILC 3σ

Theoretically clean measurement of mt

To answer this we need a precise top mass

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−10% −20% 20% 10%

20%

10%

−10%

−20%

Composite Higgs with SO(5)/SO(4)

RS with Custodial SU(2)

Little Higgs

Composite Top

AdS5 with Custodial O(3)

5D Emergent

LHC

SM/SUSY ILC

Deviations for different models for new physics scale at ~1 TeV. Based on F. Richard, arXiv:1403.2893

LHC, Ref. arXiv:1311.2028 ILC, Ref. arXiv:1307.8102

Impact of BSM on Top Sector In composite Higgs models, the top quark is often partially composite. This results in form factors in ttZ couplings, which can be measured at ILC. Beam polarization is essential to distinguish left/right-handed couplings.

Deviation in ttZ coupling of left-handed top

Deviation in ttZ coupling of right-handed top

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RS warped with Hosotani mechanism

Searches for direct production of SUSY / DM at the ILC

Sensitivity to SUSY

0 1 2 3 M3 (TeV) ~ gluino mass

Bino LSP

(Gravity

mediation)

Wino LSP

(Anomaly

mediation)

Higgsino LSP

Examples of model-independent SUSY searches •LHC: gluino search •ILC: EWK-ino (chargino/neutralino) search Compare using gaugino mass relations

ILC 500 GeV ILC 1 TeV

LHC 8 TeV (heavy squarks)

LHC 300 fb-1, √s=14 TeV

LHC 3000 fb-1, √s=14 TeV

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[Assumptions: MSUGRA/GMSB relation M1 : M2 : M3 = 1 : 2 : 6; AMSB relation M1 : M2 : M3 = 3.3 : 1 : 10.5]

Preliminary

(no relation between μ and M3)

[this comparison is for illustration only; specific channels should be looked at for actual comparisons]

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The lightest SUSY particle(LSP) is a mixture of the following three states (1) Bino (partner of U(1)Y gage boson) (2) Wino (partner of SU(2)L gauge boson) (3) Higgsino (partner of Higgs boson)

(M1, M2, μ, tanβ) point is randomly chosen 0.05<M1,M2,μ<2 TeV, 1<tanβ<70

Bino-like M1 < M2, μ Wino-like M2 < M1, μ Higgsino-like μ < M1, M2 Calculate LSP and the lightest chargino masses

Possible Dark Matter Searches at ILC The lightest and the next lightest SUSY particles

e

e

e

e

χ01

χ02

χ+1

+

+

-

-

γ Z

e

e

χ01

χ02

+

-

χ－1

e

e +

-

e

ν χ+

1

～

～

～

～

～

～

～ χ－1 ～

～

～

χ01

～ χ0

2 ～ → χ0

1 ～

χ01

～ Z or h χ01

～ χ0

1 ～

χ01

～ χ0

1 ～ χ+

1 χ－1

～ ～ → W+ W－

e

e

χ01

χ01

+

- e

e

χ01

+

-

e

～

～

～

～

～

Z

Z χ0

1

Higgsinos in Natural SUSY (ΔM ~ 1 GeV)

Hale Sert ECFA LCWS 2013, DESY EPJC (2013) 73:2660

2×M

χ

Only very soft particles in the final states → Require a hard ISR to reduce large

two-photon bkg

ISR Tagging

2×M

χ

500 fb-1 @ ECM = 500GeV P(e+,e-) = (+0.3,-0.8) and (-0.3,+0.8)

ILC as a Higgsino Factory ISR Tagging

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Power of electron polarization at ILC

Unpolarized

Scalar muon production

Background signal

μ

μ

beam

θacop μ

μR ~

Power of electron polarization at ILC

Unpolarized

Scalar muon production

Background signal Polarized (90% e-R)

μ

μ

beam

θacop μ

μR ~

Test of Gaugino Mass Unification

• EWK-ino @ ILC probe M1-M2 gaugino mass relation

– Prediction of gluino mass scale under this assumption

• Gluino @ LHC test of gaugino mass relation by LHC/ILC synergy

• Discrimination of SUSY spontaneous symmetry breaking scenarios

ILC

ILC

LHC LHC: gluino discovery mass determination ILC: Higgsino discovery M1, M2 via mixing between Higgsino and Bino/Wino

Gaugino mass unification: Higgsino-like LSP scenario [Baer, List]

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Z’ : Heavy Neutral Gauge Bosons New gauge forces imply existence of heavy gauge bosons (Z’)

LHC/ILC synergy:

•LHC discovery determine mass of Z’

•ILC measurements indirect access to couplings

Allows model discrimination

ILC: Beam polarizations improve reach and discrimination power

Z’

Z’ = 2 TeV

Z’ Search / Stud yarXiv:0912.2806 [hep-ph]hep-ph/0511335

Z’(2TeV)

1ab^-1 @ 500 GeV

ILC’s Model ID capability is expected to exceed that of LHC even if we cannot hit the Z’ pole.

Beam polarization is essential to sort out various possibilities.

Two-Ferm ion Processes

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arXiv:0912.2806 [hep-ph]

hep-ph/0511335

Z’ mass (TeV)

Mo

dels

wit

h Z

’ b

oso

n

Z’ mass (TeV) 33

ILC Detector R&D

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HCAL

ECAL

TPC

Beam line

VTX SIT FTD

ETD

SET

Return Yoke

Coil

Forward components

~15 m

• Vertex Detector: pixel detectors & low material budget

• Time Projection Chamber: high resolution & low material budget, MPGD readout

• Calorimeters: high granularity sensors, 5x5mm2 (ECAL)、3x3cm2 (HCAL)

Sensor Size ILC ATLAS Ratio

Vertex 5×5 mm2 400×50

mm2 x800

Tracker 1×6 mm2 13 mm2 x2.2

ECAL 5×5 mm2 (Si) 39×39 mm2 x61

Particle Flow Algorithm Charged particles Tracker, Photons ECAL, Neutral Hadrons HCAL Separate calorimeter clusters at particle level use best energy measurement for each particle. offers unprecedented jet energy resolution

State-of-the-art detectors can be designed for ILC

Project History and Status

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Very Brief History of the Linear Collider Project 1980s LC Accel. R&D was started at DESY, KEK, SLAC 1991 First Linear Collider Workshop (Finland ) 1990s Five major accelerator technologies were under hard competition： TESLA, S-band, C-band, X-band, CLIC 1998 Physics and detector issues are rather independent of accelerator design, “World-wide-studies of physics and detector for LCs“ was formed (grass-roots-organization) 2000 Under OECD Global Science Forum, “Consultative Group of High Energy Physics“ started (2000-2002) 2002 ICFA created ILC Steering Committee (ILCSC) 2004 International Technology Recommendation Panel (ITRP) chose super-conducting RF for the main linac technology

ILC Timeline (2005-2012)

LHC physics

2005 2006 2007 2008 2012 2009 2010 2011 2013

TDP-1 TDP-2

Letter of Intent R&D / Design

Re- baseline

Technical Design Phase (TDP)

R&D

Ref. Design

Ref. Design Baseline L

inea

r C

olli

der

C

olla

bo

rati

on

Physics Case and Research Strategy

Detector Design (Research Directorate process)

Accelerator Design (Global Design Effort process)

TDR

1st Ecm range

Higgs

B. Barish (GDE)

S. Yamada (RD)

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Linear Collider Collaboration (LCC)

Linear Collider Board Chair: Sachio Komamiya

ICFA

Director Lyn Evans

Deputy Director Hitoshi Murayama

CLIC Accelerator Steinar Stapnes

ILC Accelerator Mike Harrison

Physics & Detectors Hitoshi Yamamoto

PAC Chair: Norbert Holtkamp

Linear Collider Collaboration (LCC)

Regional Directors Harry Weerts, Brian Foster

Akira Yamamoto

ICFA = International Committee for Future Accelerators

PAC = Project Advisory Committee

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European Strategy approved by CERN Council, June 2013 Chair: Tatsuya Nakada (Swiss Federal Institute of Technology Lausanne)

Supports from the World

Asia ACFA-HEP Chair: Mitsuaki Nozaki (KEK) 3rd ACFA-HEP Meeting on 17.07.2013 in Chiba

USA Particle Physics Project Prioritization Panel (P5) Report, May 2014

Drivers: Higgs* Neutrino Mass Dark Matter* Dark Energy/Inflation New Particles/Interactions* *where the ILC can contribute

Strong emphasis on global cooperation!

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The selected site in Japan Kitakami mountains (stable granite hilly district) >100m underground, no active faults Granite rock range

Earthquake safe

Advanced Accelerator Association of Japan (AAA)

Industry: 100 companies （Mitsubishi HI、Toshiba、Hitachi、Mitsubishi Electric、Kyoto Ceramic et al.） Academy: 45 institutes （KEK，Tokyo、Kyoto、Tohoku, Kyushu, RIKEN, JAEA et al.)

as of December 2014

Union of Diet members to promote a construction of international laboratory for LC

31st July 2008 established a suprapartisan ILC supporters

(July 2008〜) President Kaoru Yosano Deputy Yukio Hatoyama Secretary-General Takeo Kawamura 、 Yoshihiko Noda Director Norihisa Tamura Masamitsu Naito

Akihito Ohhata、Koji Omi、Ikuo Kamei, Takeo Kawamura, Tetsuo Saito, Yoshiaki Takagi, Norihiko Tamura, Masamitsu Naito, Yoshihiko Noda, Yukio Hatoyama、 Fumuhiro Himori, Kosuke Hori, Eisuke Mori, Kaoru Yosano、Hidekatsu Yoshii

proposers

Supreme advisor Kaoru Yosano President Emeritus Masatoshi Koshiba President Takashi Nishioka (Mitsubishi HI） Trustee Atsuto Suzuki （KEK) 〃 Akira Maru （Hitachi）、 〃 Yoshiaki Nakaya （Mitsubishi Electric） 〃 Yasuji Igarashi （Toshiba）、 〃 Akira Noda （Kyoto University） 〃 Keijiro Minami （Kyoto ceramic） Auditor Sachio Komamiya (University of Tokyo）

New Officers (October 2011〜) Supreme advisor Kaoru Yosano President Yukio Hatoyama Acting president Takeo Kawamura Secretary-general Tatsuo Kawabata Deputy Tatsu Shionoya Dupty President Tetsuo Saito President of bureau Norihisa Tamura Director of bureau Keisuke Tsumura Deputy Takeshi Kai

AAA homepage http://aaa-sentan.org

June 2008 established an industry-academy collaboration

Renewed on 1st Feb 2013 lead by Takeo Kawamura

Technologies brought by HEP and Astrophysics

Accurate atomic clock was invented to experimentally prove Einstein’s general relativity ⇒ brought GPS（car navigation system, map on Smartphones）

Scientists at CERN tried to exchange data/information via computers ⇒ Invention of World-Wide-Web (WWW) ⇒ Internet, Information-oriented society

Accelerator technologies for particle physics ⇒ Medical accelerators（cancer therapy, sterilization)

⇒ Superconductive technology （Superconductive magnets, magnetic levitation train = Linear motor car)

Economy Industry

CERN

tion

International Linear Collider ILC The next major accelerator project driven by truly international efforts Superconducting linear accelerator of ~30km length will be constructed underground in Iwate, Japan ILC will address fundamental questions beyond the Standard Model What is the physics behind the EW symmetry breaking ? What is the nature of Dark Matter ? …

The Subcommittee on Future Projects of Japanese High Energy Physics

•Subcommittee members are all younger than 50 years old at the start of the subcommittee.

•Handed the report to HEPC on February 11, 2012

•Endorsed by Japanese Association of High-Energy Physicists (JAHEP) in March 2012

Chair: Toshinori Mori (ICEPP, The University of Tokyo)

Consensus building in Japanese particle physics society

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Recommendation of subcommittee for future projects of Japanese HEP

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A Proposal for a Phased Execution of the International Linear Collider Project The Japan Association of High Energy Physicists (JAHEP) endorsed the document on 18 October 2012

ILC shall be constructed in Japan as a global project based on agreement and participation by the international community. Physics : Precision study of the Higgs Boson, top quark, “dark matter” particle, and Higgs self-coupling, Scenario : Start with a Higgs Boson Factory ~250 GeV. Upgraded in stages up to a center-of-mass energy of ~500 GeV, which is the baseline energy of the overall project. Technical extendability to a 1 TeV region shall be secured. Japan covers 50% of the expenses (construction) of the overall project of a 500 GeV machine. The actual contributions, however, should be left to negotiations among the governments.

ILC budget (India version)

Rupees/Euro/Yen/Dollar per １０ person per year

~10 years

Accelerator ~ 8B$ ~800Byen