1. Report on model separation Masaki Asano (Tohoku U.) The 12th general meeting of the ILC physics working group

2. Dark Matter WIMP  Neutral  Massive  Stable http://map.gsfc.nasa.gov/ (Weakly Interacting Massive Particles) ~ 0.1 DM abundance is establish by WMAP. One of the most plausible candidate: The nature is WIMPs are also able to account for the large scale structure of the presence universe. It is also plausible that DM appears in TeV new physics model which are motivated as the solution of the hierarchy problem (which should be solved at ~ TeV). WMAP results show that WIMP DM mass m χ is around 100 GeV.

3. Littlest Higgs Model  SUSY transforms bosons into fermions and vice versa.  Cancelation of the Quadratic div. to Higgs mass term is guaranteed by the supersymmetry. Inert Doublet Model SUSY Model  Higgs boson is regarded as a pseudo Nambu-Goldstone boson  The quadratic div. vanish at one-loop level due to the collective symmetry breaking. N. Arkani-Hamed, A. G. Cohen, H. Georgi (’01)  2 Higgs doublet model in which 1 doublet has Z2-odd parity.  Higgs mass ~ 500GeV while avoiding EWPM constraints. R. Barbieri, L. J. Hall, V. S. Rychkov (’06)

4. Littlest Higgs Model  SUSY transforms bosons into fermions and vice versa.  Cancelation of the Quadratic div. to Higgs mass term is guaranteed by the supersymmetry. Inert Doublet Model SUSY Model  Higgs boson is regarded as a pseudo Nambu-Goldstone boson  The quadratic div. vanish at one-loop level due to the collective symmetry breaking. N. Arkani-Hamed, A. G. Cohen, H. Georgi (’01)  2 Higgs doublet model in which 1 doublet has Z2-odd parity.  Higgs mass ~ 500GeV while avoiding EWPM constraint. R. Barbieri, L. J. Hall, V. S. Rychkov (’06) SM particles + R-odd SM partner (spin is different) SM particles + T-odd SM partner (spin is same) SM particles + Z2-odd Higgs doublet

5. Dark Matter Candidates WIMP The spin of DM candidate comes in a variety of types.  η I (dark Higgs) 0 Inert Doublet  χ 0 (neutralino) ½ SUSY  A H (heavy photon) 1 Littlest Higgs spinmodel How to distinguish the dark matter nature in different new physics models @ ILC ?

6. To distinguish the dark matter nature, We concentrate on this process: W-W- W+W+ X0 X+ X- Charged new particle Dark matter @ 500 GeV and @ 1 TeV ILC In this study, we use same M_X^-, MX^0 mass and cross sections for each models.

7. SUSY W-W- W+W+ X0 X+ X- X0: Neutralino spin ½ X+: Chargino spin ½ For example,

8. SUSY W-W- W+W+ X0 X+ X- X0: Neutralino spin ½ X+: Chargino spin ½ For example, Since WIMP DM is interact SM particle weakly, the DM will interact W+- gauge boson. To conserve the charge and Z2- symmetry, the interaction also includes Charged New Particles. W+W+ X0

9. SUSY W-W- W+W+ X0 X+ X- X0: Neutralino spin ½ X+: Chargino spin ½ For example, Since WIMP DM is interact SM particle weakly, the DM will interact W+- gauge boson. To conserve the charge and Z2- symmetry, the interaction also includes Charged New Particles. W+W+ X0 X+

10. SUSY W-W- W+W+ X0 X+ X- X0: Neutralino spin ½ X+: Chargino spin ½ For example, Since WIMP DM is interact SM particle weakly, the DM will interact W+- gauge boson. To conserve the charge and Z2- symmetry, the interaction also includes Charged New Particles. W+W+ X0 X+ Other WIMP scenario will also have this mode!

11. Littlest Higgs with T-parity W-W- W+W+ AHAH AHAH WH+WH+ WH-WH- A H : Heavy Photon spin 1 W H + : Heavy W boson spin 1 SUSY X0: Neutralino spin ½ X+: Chargino spin ½ W-W- W+W+ X0 X+ X- Inert Doublet model W-W- W+W+ ηＩηＩ ηＩηＩ η+ η- η Ｉ : Neutral Inert Higgs spin 0 η + : Charged Inert Higgs spin 0

12. we will measure Angular distribution of charged new particles X ± Angular distribution of jets from W ± polarization X +- spin The decay vertex structure masses mass relation between X 0 & X +- will confirm the model. W-W- W+W+ X0 X+ X- From this mode, (e.g. The vertex arises from EWSB or not)

13. Inert DoubletSUSYLittle Higgs Angular distribution in three models @ Since, angular distribution is different from each models, this is the powerful probe of the dark matter nature. N. Okada Keisuke Fujii (KEK) Katsumasa Ikematsu (KEK) Rei Sasaki (Tohoku U.) Taikan Suehara (ICEPP, U. of Tokyo) Yosuke Takubo (Tohoku U.) Ryo Yonamine (Sokendai) R.S. Hundi (U. of Hawaii) Hideo Itoh (KEK) Shigeki Matsumoto (Toyama U.) Nobuchika Okada (KEK) Generic WIMP study!

14. Simulation results 14 Preliminary !!!

15. Angular distribution in three models @ 1TeV ILC Preliminary !!! Saito

16. Angular distribution in three models @ 1TeV ILC Preliminary !!! Saito mistake?

17. Threshold scan @ 1TeV ILC we can also distinguish each model because the energy dependence are different. Preliminary !!! Saito mistake?

18. But… There are also t-channel diagram. What we were discussing earlier is the situation in which t-channel particle is very heavy.

19. But… In these models, there are also t-channel process. When νH is very heavy, t-channel is neglidgible (the case that we were discussing earlier), there will be no asymmetry. If the t-channel process is significant, the cross section shows big FB asymmetry. Ex. LHT N. Okada W-W- W+W+ AHAH AHAH WH+WH+ WH-WH- W-W- W+W+ AHAH AHAH WH+WH+ WH-WH-

21. No T-channel mode

22. Angular distribution in three models @ 1TeV ILC for several sneutrino & heavy neutrino mass. At 1 TeV ILC, we can measure T-channel particle mass < 500 GeV. At LHC, measurement of heavy their mass is also difficult (< 1 TeV).

23. In the case in which we will measure the sneutrino or heavy neutrino mass, we will distinguish to dark matter nature using the mass! In the case in which we cannot measure the sneutrino or heasy neutrino mass at LHC & ILC, Can we distinguish to dark matter nature ? Some distributions seem similar shape. But…

24. In all case, angular distributions behave differently at edges We place MSSM distribution on top of LH distribution

25. In the case in which we cannot measure the sneutrino or heasy neutrino mass at LHC & ILC, Can we distinguish to dark matter nature using angular distribution & threshold scan? Next study In some situation, W charge ID is important?

26. 26 e-e- e+e+ WH+WH+ W+W+ AHAH WH-WH- AHAH W-W- W H ± candidates are reconstructed as corn around W ±. If W H + and W H - are assumed as back-to-back, there are 2 solutions for W H ± candidates. In this mode, however, 2 solutions should be close to true W H ±. W+W+ W-W- WH+WH+ WH-WH- Distribution of production angles of W H +  Production angle of W H ± spin-1 This shape shows W H ± spin as spin-1. Angular distribution of jets W+W+ j1j1 j2j2  j1j1 j2j2 longitudinal W ± helicity as longitudinal mode. Angular distribution of jets in the helicity-frame of the W ± carries information on the polarization of the W ±.

27. 27 Production angle of W H ± Angular distribution of jets from W ± Other parameters W H is spin 1 particle! The dominance of the longitudinal mode! The coupling arises from EWSB! Beam polarization W H has SU(2) L charge, but no U(1) Y charge! 100% RH polarization

28. 28 Other parameters Cross section Heavy lepton mass! @ 1 TeV ILC @ 500 GeV ILC Heavy lepton masses depend on Yukawa k_l. k_l can be determined with 22.1% accuracy at 500 GeV, 0.5% accuracy at 1 TeV.