1. Hong-Jian He Tsinghua University 9th ACFA ILC Workshop Physics Session Summary Feb. 4-7, 2007, IHEP, Beijing

2. Consensus: “Future” of ILC strongly depends on What New Phys LHC will discover. LHC 2007-

3. Zhengguo Zhao, ( Anomalous Gauge Boson Coupling ) Zhengguo Zhao, ( Anomalous Gauge Boson Coupling ) Diboson Production and Triple Gauge Boson Couplings at TeV Hadron Collider Diboson Production and Triple Gauge Boson Couplings at TeV Hadron Collider Denis Perret-Gallix, ( Calculation Tool: Grace ) Denis Perret-Gallix, ( Calculation Tool: Grace ) Simulate with Grace Simulate with Grace Kingman Cheung, ( Higgs: Very Light A 0 ) Kingman Cheung, ( Higgs: Very Light A 0 ) Phenomenology of the Light Pseudoscalar Boson in NMSSM Phenomenology of the Light Pseudoscalar Boson in NMSSM Eri Asakawa, ( Exotic Higgs-Gauge-Coupling: H ＋ W － Z 0 ) Eri Asakawa, ( Exotic Higgs-Gauge-Coupling: H ＋ W － Z 0 ) Potential for Measuring the H ＋ W － Z 0 vertex at colliders Potential for Measuring the H ＋ W － Z 0 vertex at colliders Liang Han, ( NLO EW Corrections ) Liang Han, ( NLO EW Corrections ) Theoretical Calculation for ILC Precise Measurement Theoretical Calculation for ILC Precise Measurement Jin Min Yang, ( SUSY: Splitting Model ) Jin Min Yang, ( SUSY: Splitting Model ) Split Supersymmetry at ILC Split Supersymmetry at ILC Shou-hua Zhu, ( Exotic Higgs A 0 : 0.215GeV ) Shou-hua Zhu, ( Exotic Higgs A 0 : 0.215GeV ) Unique Higgs Boson Signature at Colliders Unique Higgs Boson Signature at Colliders Koichi Matsuda, ( Anomalous Higgs Yukawa: ee→ννtt, ee→htt ) Koichi Matsuda, ( Anomalous Higgs Yukawa: ee→ννtt, ee→htt ) New Physics Search by Helicity Decomposition of Heavy Fermion Pair-Production from W-boson Fusion at LHC/ILC New Physics Search by Helicity Decomposition of Heavy Fermion Pair-Production from W-boson Fusion at LHC/ILC Hideo Itoh, ( SUSY-breaking/brane world: TeV-scale X ) Hideo Itoh, ( SUSY-breaking/brane world: TeV-scale X ) Low scale supergravity mediation in brane world scenario Low scale supergravity mediation in brane world scenario and hidden sector Phenomenology and hidden sector Phenomenology W. Lohmann, ( Higgs: Detector Full simulation/Reconstruction ) W. Lohmann, ( Higgs: Detector Full simulation/Reconstruction ) Study of ee→Zh→llX using full detector simulation and exact reconstruction Study of ee→Zh→llX using full detector simulation and exact reconstruction

4. Central Physics Issues for LHC & ILC  Why TeV Scale ?  What New Physics ?  How to Compute/Observe: Signals vs Bkgnds ?  How does ILC play Complementarity to LHC?

5. New Physics at TeV Scale ?? Which is Guaranteed ?? Higgsless Higgs

6.  Hierarchy/Fine-Tuning Problem ? → Not strong enough ! → Not strong enough !  Unification ? → Many possible realizations ! → Many possible realizations !  Light Higgs ? → Not enforced by data ! → Not enforced by data !  Then, WHAT best justifies TeV Scale? … WHAT best justifies TeV Scale? … New Physics at TeV Scale ?

7. Fine-Tuning Problem ? Fine-Tuning Problem ? ● Radiative Corrections to Higgs Mass: ● Degree of Fine-Tuning (DFT): DFT = 200 2 /[|-2000 2 +520 2 +460 2 |*(Λ/10TeV) 2 ]

8. Fine-Tuning is a Technical Problem ! Fine-Tuning is a Technical Problem ! Not strong enough for LHC/ILC! Λ=11TeV 3.5TeV 2.5TeV

9. SM Higgs Potential runs into more serious Vacuum Energy Problem even at Tree-Level: ( eg, S.Weinberg,1989 ) = V min – λv 4 /4 = V min － O(100GeV) 4 == (10 - 4 eV) 4 → 60 Orders of Magnitude Fine-tuning ! → So, Why do we care 1% Tuning at 1-Loop ?!

10. Unification without SUSY? Unification without SUSY? → YES. → Many possible realizations !!! Trinification with just 6 Higgs doublets (Willenbrock et al, 2003) 5d TeV GUT with just 3 real scalars of SU(2)-adjoint (Dienes etal, 1998) And more: Efficacious Unification with 2 scalar octocts, 1 triplet scalar, 1 triplet majorana fermiom, which also predicts dark matter, as good as Splitting SUSY (E. Ma, 05), ……… Trinification 5d TeV GUT

11. A Misconception: Light Higgs from Data ? 114.4 < M H < 260GeV (95%CL) → Could be True Only If No New Physics & Higgs was Exactly SM-like!

12. Heavy Higgs vs Precision Data: No Problem ! Heavy Higgs vs Precision Data: No Problem ! R. S. Chivvukula, Snowmass-2001H. J. He, Snowmass-2001 Top Seesaw Model

13. SUSY with Heavy Higgs: OK… Called “λSUSY” See Y. Nomura’s talk, hep-ph/0607332 ● λSH 1 H 2 remains perturbative up to about 10TeV ● M h is heavy, up to 300GeV ● Higgs/Higgsino: 200-700GeV

15. Lesson for LHC & ILC: Lesson for LHC & ILC: Keep Your Mind Fully Open !!! Keep Your Mind Fully Open !!!

16. The Real Problem with Particle Masses is Unitarity Violation Unitarity Violation in the High Energy Scattering !!!!!

17. Unitarity of W L W L → W L W L : Electroweak Symmetry Breaking Scale Unitarity of W L W L → W L W L : Electroweak Symmetry Breaking Scale → Stronger & More Robust than Fine-tuning bound !

18. Scales of Fermion Mass Generation

19. → Future: After LHC/ILC !

20. K. Cheung’s talk: NMSSM How to Observe ? Large tanβ & v s J.M. Yang’s talk: Splitting SUSY S.H. Zhu’s Talk ee→Zh →Z+4μ

21. Probing Higgsless Parameters: E vs Polarization Han, He, Yuan

22. Higgsless Model: New W’ at ILC

23. Conclusions Conclusions  Why TeV Scale: Unitarity of W L W L → W L W L ILC must be upgradeable to 1TeV ! ILC must be upgradeable to 1TeV !  What New Physics: Many Kinds – Keep your Mind Open !!! Light Higgs or Heavy Higgs or Higgsless; Light Higgs or Heavy Higgs or Higgsless; SUSY or Splitting SUSY or SUSY-Less; SUSY or Splitting SUSY or SUSY-Less; 4-Dimension or Extra-d or Deconstruction… 4-Dimension or Extra-d or Deconstruction…  How to Compute/Observe at ILC: Signals vs Bkgnds New Channels, Beam polarizations, New Channels, Beam polarizations, e-e- Mode, Photon-collider, …… e-e- Mode, Photon-collider, ……  ILC plays Complementarity: Precision Test, Loop Effects, …… Precision Test, Loop Effects, ……

25. Back Up Slides Back Up Slides

28. VLHC: http://vlhc.org (50-200TeV)http://vlhc.org

29. New Phys

31. LHCILC

32. Importance of Photon Collider & Polarization (Charged Higgs Boson Production)

33. Different SUSY Breakings and Particle Spectrum: Need Precision Tests at ILC !