1. Neutralino Dark Matter in Light Higgs Boson Scenario Masaki Asano (ICRR, University of Tokyo) Collaborator S. Matsumoto (Toyama Univ.) M. Senami (Kyoto Univ.) H. Sugiyama (SISSA) Phys.Lett.B663:330

2. Introduction What is the Light Higgs boson scenario?

3. Is LHS also compatible with GUT and Dark Matter? We search the region where consistent with  particle physics experiments  cosmological observations. Possibility of the dark matter direct detection in LHS. Introduction What is Light Higgs boson Scenario (LHS)? is referred to as LHS in this talk. MSSM with m h < 114.4 GeV Recently, G.L.Kane, T. T. Wang, B. D. Nelson and L. T. Wang (2005), M. Drees (2005), A. Belyaev, Q. H. Cao, D. Nomura, K. Tobe, C. P. Yuan (2006), S. G. Kim, N. Maekawa, A. Matsuzaki, K. Sakurai, A. I. Sanda, and T. Yoshikawa (2006), S. G. Kim, N. Maekawa, K. I. Nagao, K. Sakurai, and T. Yoshikawa (2008) …….. Our interest Recent works of LHS: consistency with LEP results, phenomenological aspect and a solution to the little hierarchy problem are discussed.

4. tan  = ratio of vevs,  : mixing Higgs Boson Mass Limit from Direct Search at LEP ・ in SM, Lower limit : m h > 114 GeV (from lack of the direct signal at LEP II) ・ in MSSM, There are 2 Higgs doublets. →The coupling can be different! →The LEP limit may be lower than 114 GeV. If sin(β - α) is small, LHS can be realized. Introduction

5. tan  = ratio of vevs,  : mixing Higgs Boson Mass Limit from Direct Search at LEP ・ in SM, Lower limit : m h > 114 GeV (from lack of the direct signal at LEP II) ・ in MSSM, There are 2 Higgs doublets. →The coupling can be different! →The LEP limit may be lower than 114 GeV. If sin(β - α) is small, LHS can be realized. Introduction ・ in MSSM, we should take care of the other mode. (This mode is suppressed due to the p-wave production as long as m A ~ m Z.)

6. Introduction What is Light Higgs boson Scenario (LHS)? is referred to as LHS in this talk. MSSM with m h < 114.4 GeV Our interest To avoid ZAh constraint, we investigate around 90 < m h < 114 GeV. Is LHS also compatible with GUT and Dark Matter? We search the region where consistent with  particle physics experiments  cosmological observations. Possibility of the dark matter direct detection in LHS. Recent works of LHS: consistency with LEP results, phenomenological aspect and a solution to the little hierarchy problem are discussed. Recently, G.L.Kane, T. T. Wang, B. D. Nelson and L. T. Wang (2005), M. Drees (2005), A. Belyaev, Q. H. Cao, D. Nomura, K. Tobe, C. P. Yuan (2006), S. G. Kim, N. Maekawa, A. Matsuzaki, K. Sakurai, A. I. Sanda, and T. Yoshikawa (2006), S. G. Kim, N. Maekawa, K. I. Nagao, K. Sakurai, and T. Yoshikawa (2008) ……..

7. 1. SM Higgs can not explain the excess, because the number of the excess events corresponds to about 10% of that predicted in the SM. 2. MSSM maybe explain this excess if the LHS is realized! LEP has found the excess from expected BG around m h = 98 GeV. □ 115 GeV ： 1.7σexcess □ 98 GeV ： 2.3σexcess Introduction

8. Light Higgs boson Scenario To realize the LHS, sin(β-α) has to be small.

9. Assuming  Large radiative corrections Mass eigenstates of neutral Higgs bosons are described by small sin(β - α) Neutral Higgs mass matrix

10. h (η 2 ) H (η 1 ) mA2mA2  mZ2mZ2 mA2mA2  mZ2mZ2 h (η 1 ) H (η 2 ) Lightest Higgs consists of up-type. → cos α ~ 1, α ~ 0 → sin(β-α) ~ 1 → g ZZh ~ g ZZHSM (SM Higgs limit is applied) usual scenario (m A 2 >> m Z 2 ) Lightest Higgs consists of down-type. → sin α ~1, α ~ π/2 → sin(β-α) is small → g ZZh << g ZZHSM (SM Higgs limit is avoided) LHS (m A 2 ~ m Z 2 ) In LHS, all Higgs bosons are light. m A 2 ~ m H± 2 ~ m H 2 ~ m h 2  small sin(β - α),

11. h (η 2 ) H (η 1 ) mA2mA2  mZ2mZ2 mA2mA2  mZ2mZ2 h (η 1 ) H (η 2 ) Lightest Higgs consists of up-type. → cos α ~ 1, α ~ 0 → sin(β-α) ~ 1 → g ZZh ~ g ZZHSM (SM Higgs limit is applied) usual scenario (m A 2 >> m Z 2 ) Lightest Higgs consists of down-type. → sin α ~1, α ~ π/2 → sin(β-α) is small → g ZZh << g ZZHSM (SM Higgs limit is avoided) LHS (m A 2 ~ m Z 2 ) In LHS, all Higgs bosons are light. m A 2 ~ m H± 2 ~ m H 2 ~ m h 2  small sin(β - α),

12. h (η 2 ) H (η 1 ) mA2mA2  mZ2mZ2 mA2mA2  mZ2mZ2 h (η 1 ) H (η 2 ) Lightest Higgs consists of up-type. → cos α ~ 1, α ~ 0 → sin(β-α) ~ 1 → g ZZh ~ g ZZHSM (SM Higgs limit is applied) usual scenario (m A 2 >> m Z 2 ) Lightest Higgs consists of down-type. → sin α ~1, α ~ π/2 → sin(β-α) is small → g ZZh << g ZZHSM (SM Higgs limit is avoided) LHS (m A 2 ~ m Z 2 ) In LHS, all Higgs bosons are light. m A 2 ~ m H± 2 ~ m H 2 ~ m h 2  small sin(β - α),

13. Results (LHS Allowed region in NUHM ) (Non-Universal scalar masses for the Higgs Multiplets) m 0, m Hu, m Hd, m 1/2, A 0, sign(  m 0, m 1/2, A 0, tan , , m A Weak scale Using this, we can study the MSSM Higgs sector in detail.

14. Charged LSP WMAP allowed region co-annihilation funnel example parameter set

15. Charged LSP WMAP allowed region co-annihilation funnel Light H ± contribution should be canceled by chargino one. In particular, light H ± contribution can be compensated by large A-terms. A-term Bs→γ: example parameter set

16. Charged LSP WMAP allowed region co-annihilation funnel Br(B s →μμ) ∝ (tanβ) 6 /(m A ) 4 tanβ Bs →μ + μ - : light H ± contribution should be canceled by chargino one. In particular, light H ± contribution can be compensated by large A-terms. A-term Bs→γ: Because m A is small, large tanβ ( 20) is excluded. example parameter set

17. Charged LSP WMAP allowed region co-annihilation funnel Br(B s →μμ) ∝ (tanβ) 6 /(m A ) 4 tanβ Bs →μ + μ - : light H ± contribution should be canceled by chargino one. In particular, light H ± contribution can be compensated by large A-terms. A-term Bs→γ: Because m A is small, large tanβ ( 20) is excluded. Allowed region

18. CONSTRAINTS Parameter Scan 80 < m A < 140 GeV tan  = 10 ( , A 0 ) GeV = (300, –700), (600, –1000), (700, –1100) WMAP LEP2 Higgs search Zh/ZH & Ah/AH SUSY particle searches Color/Charged breaking Br( b  sγ ) & Br( B s  μ + μ – ) For several value of μ, we search the region which is consistent with following constraints.

19. CONSTRAINTS Parameter Scan 80 < m A < 140 GeV tan  = 10 ( , A 0 ) GeV = (300, –700), (600, –1000), (700, –1100) WMAP LEP2 Higgs search Zh/ZH & Ah/AH SUSY particle searches Color/Charged breaking Br( b  sγ ) & Br( B s  μ + μ – ) funnel region Mixing region coannihilation region For several value of μ, we search the region which is consistent with following constraints. The LHS region consistent with the WMAP observation exists! Too Large μ is not favored (No region for μ > 800 GeV)

20. Direct detection Because DM often passes through the Earth, DM sometimes interacts with nucleus inside the detector. Direct detection observes nuclear recoil as DM scatter of them.

21. … Now, all Higgs are light. Then, prediction for this cross section is large. 1.Small μ is not favored from direct detection experiments. 2. Even for large μ, it is possible to detect the signal at on-going experiments! Direct detection

22. … Now, all Higgs are light. Then, prediction for this cross section is large. 1.Small μ is not favored from direct detection experiments. 2. Even for large μ, it is possible to detect the signal at on-going experiments! Direct detection

23. … Now, all Higgs are light. Then, prediction for this cross section is large. 1.Small μ is not favored from direct detection experiments. 2. Even for large μ, it is possible to detect the signal at on-going experiments! Direct detection XMASS

24. Summery

25. Light Higgs Boson Scenario is one of interesting candidates for new physics at TeV scale. The scenario is consistent with not only particle physics experiments but also cosmological observations. The scenario predicts a large scattering cross section between dark matter and ordinary matter, thus it will be tested at present direct detection measurements for dark matter. We will scan all parameter space to search the lower limit of tanβ (which determines lower limit of Br(B s  μ + μ – ) in LHS). Using the limit, LHS can be tested by near future. Almost all SUSY particles are predicted to be light, these particles will be copiously produced at colliders. Summery