Particle Physics beyond the Standard Model and the ILC Project · Particle Physics beyond the...
Transcript of Particle Physics beyond the Standard Model and the ILC Project · Particle Physics beyond the...
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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-
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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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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 +
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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
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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