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Prospect after discoveries of Higgs/SUSYYasuhiro Okada (KEK)“Discoveries of Higgs and Supersymmetry to Pioneer Particle Physics in the 21st Century” November 25, 2005, Univ. of Tokyo
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(1) Higgs Physics
Finding the mass-generation mechanism for gauge bosons, quarks and leptons the most urgent question of the present particle physics.
Discovery of the Higgs boson is the first step. The answer is most probably related to what is
physics beyond the standard model. The electroweak symmetry breaking requires dynamics beyond the SU(3)xSU(2)xU(1) gauge interactions.
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How we have come to understand the strong interaction.
Structure of a nucleus
(proton / neutron)
Discovery of Yukawa meson
Quark model QCD
Discovery of the Higgs boson is similar to discovery of the Yukawa mesonin understanding the weak interaction.
Weak interaction Higgs mechanismDynamics behind the EW symmetry
breaking
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A Higgs sector is unknown :How many Higgs bosons? (is there any?)What is the mass ?What is SU(2) representation?
Even if one Higgs doublet model is a good description,
What is ?What physics determines –^2?What physics determines?
Different scenarios provides different answers.
SUSY, String TheoryComposite model, Little Higgs modelTeV scale extra dimension
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~10 TeV
Gravity
Gauge force
Composite model
Extra dimension
SUSY GUT
Various new physics signalsare expected in the TeV region, depending on differentsignals.
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Higgs mass
If we require that the SM is validup to 10^19 GeV,
Large Higgs mass Large self-coupling Strong dynamics
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Two interesting cases
(1) Low mass Higgs boson (< 130 GeV)
SUSY (mh< 135 GeV for MSSM)
or
Higgs potential is generated at low energy scale (< 0(10) TeV )
Ex. Pseudo Nambu-Goldstone boson
(2) High mass Higgs boson (>300 GeV)
Something is needed to be consistentwith the EW precision data.
mh=100 GeV 200
300500
1000
M.Peskin and J.Wells
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Higgs coupling LHC 0(10)% for ratio of the coupling constants
ILC A few % for absolute valuesof various coupling
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Indirect constraint on the heavy Higgs boson mass in MSSM
Direct search at LHC
Direct search at 1TeV LC
ACFA report
ACFA Higgs WGS. Kiyoura, et al
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SUSY loop contributions to the hbb Yukawa coupling
J.Guasch, W.Hollik,S.Penaranda
B(h->bb)/B(h->is sensitive tothe SUSY loop correction to thebottom Yukawa coupling for alarge tanregion.
K.S.Babu, C.Kolda: M.Carena, D.Garcia, U.Nierste, C.E.M.Wagner
B(h->bb)/B(h->) nomalized by SM value
LC
LHC
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Higgs self-coupling measurementAccess to the Higgs potential.Precision at 1/ab for 120 GeV Higgs boson ~20% for 500GeV ILC ~10% for 1 TeV ILC
Y.Yasui, et al, LCWS 02
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Electroweak baryogenesis and Higgs potential
Electroweak Baryogenesis
First order phase transition Extension of the Higgs sector
The Higgs potential at zero temperature is also modified.=> Self coupling measurement
2HDM C.Grojean,G.Servant, J.D.WellsS.Kaenmura, Y. Okada, E.SenahaModel with dim 6 potential
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(2) Supersymmetry Supersymmetry is a revolution of physics similar
to relativity, if it is found. SUSY provides a coherent picture of particle phy
sics and cosmology
SUSY + GUT => Gauge coupling unificationSUSY + R parity => Dark matter SUSY + Seesaw neutrino => Leptogenesis (Baryon number of the Universe)
After we confirm the supersymmetry, whether these ideas are realized could be central issues.
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SUSY and GUT
SUSY breaking scenario
LHC/LC combined analysis
G.A.Blair, W.Porod,and P.M.Zerwas
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Dark matterALCPG cosmology subgroup
WMAP
PLANCK
SUSY mass and coupling measurements=> Identification of dark matter
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SUSY Seesaw modelLarge Lepton flavor violation processes are expected.
T.Goto,Y.Shimizu,T.Shindo,M.Tanaka and Y.Okada.
J.Hisano, M.M.Nojiri, Y.Shimizu, M.Tanaka
->ein SU(5) SUSY GUTwith seesaw neutrino Slepton flavor mixing
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Conclusions
Discovery of the Higgs boson is the first step to understand the dynamics of the electroweak symmetry breaking.
Measurements of the Higgs coupling constants can provide hints to new physics.
SUSY, if it exists, has far-reaching consequences in particle physics and cosmology.
