1. 朱守华, 北京大学物理学院

2. Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies.
The discovery, using NASA's Chandra X-ray Observatory and other telescopes, gives direct evidence for the existence of dark matter.
朱守华, 北京大学物理学院

3. Q: Is dark matter relevant to weak scale physics? A: Likely.
Q: If yes, where to insert dark matter sector? A: Most likely in Higgs sector because success of standard model of particle physics permits naturally the additional sector in Higgs sector.
朱守华, 北京大学物理学院

4. Scalar Cold Dark Matter (CDM)
and Higgs Boson
Hep-ph/
Hep-ph/ (EPJC2006)
朱守华（Shou-hua Zhu）
Peking University
朱守华, 北京大学物理学院

5. I: Light (~mw) new freedom could exist in Higgs sector
朱守华, 北京大学物理学院

6. Existence of CDM is well-established(?) and we know:
朱守华, 北京大学物理学院

7. But we don’t know: Which particle is CDM? Neutralino in SUSY models?
(SM gauge group) singlet scalar?
朱守华, 北京大学物理学院

8. Scalar cold dark matter model:
Assume:
(simplest model)
朱守华, 北京大学物理学院

9. In simplest cold dark matter model:
朱守华, 北京大学物理学院

10. Relic density of CDM (standard procedure):
SM particles: ff-bar
WW(*)
ZZ(*)
朱守华, 北京大学物理学院

11. Calculation of CDM relic density: C. Burgess etal, NPB619(2001)709
朱守华, 北京大学物理学院

12. Allowed region
朱守华, 北京大学物理学院

13. Relic density of DM + Higgs mass lower and upper bounds =>
So what?
朱守华, 北京大学物理学院

14. by W. de Boer etal. Background + signal describe EGRET data!
朱守华, 北京大学物理学院

15. Summary from W. De Boer
10σ EGRET excess shows all key features from DM annihilation:
Excess has same shape in all sky directions: everywhere it is
perfectly (only?) explainable with superposition of
background AND mono-energetic quarks of GeV
Results consistent with minimal SUPERSYMMETRY
Excess follows expectations from galaxy formation:
cored 1/r2 profile with substructure,
visible matter/DM0.02
Significance >10σ with >1400 indep. data points
Excess is TRACER OF DM, since it can explain
peculiar shape of rotation curve
Results model independent, since only KNOWN spectral shapes of signal and background used, NO model dependent calculations of absolute fluxes.
Conventional models CANNOT explain above points SIMULTANEOUSLY,
especially spectrum of gamma rays in all directions, shape of rotation curve,
stability of ring of stars at 14 kpc and ring of H2 at 4 kpc.,..
朱守华, 北京大学物理学院

16. In other words:
Mono-energetic quarks ( GeV)
朱守华, 北京大学物理学院

17. Invisible Higgs decay: H->SS
朱守华, 北京大学物理学院

18. Invisible Higgs decay: H->SS
朱守华, 北京大学物理学院

19. II: Detecting light invisible Higgs Boson via pp->ZH mode
朱守华, 北京大学物理学院

20. ZH is similar to Zhu (thank you, F. Lu!)
Why ZH channel?
ZH is similar to Zhu (thank you, F. Lu!)
ZH tends to have SM-like coupling
Z can be excellently reconstructed via charged lepton pair
朱守华, 北京大学物理学院

21. 朱守华, 北京大学物理学院

22. 朱守华, 北京大学物理学院

23. 朱守华, 北京大学物理学院

24. My contributions
朱守华, 北京大学物理学院

25. 朱守华, 北京大学物理学院

26. 朱守华, 北京大学物理学院

27. 朱守华, 北京大学物理学院

28. 朱守华, 北京大学物理学院

29. 朱守华, 北京大学物理学院

30. 朱守华, 北京大学物理学院

31. Summary The Higgs boson is light and may decay dominantly into DM.
Seems everything is perfect: Higgs mass bounds can predict scalar CDM value and EGRET prefers the same mass region.
The Higgs boson is light and may decay dominantly into DM.
We are listening what LHC/ILC will tell us!
朱守华, 北京大学物理学院

32. Thanks for your attention!
朱守华, 北京大学物理学院