1. Testing Seesaw at LHC
郑亚娟

2. Outline Mini-review of neutrino physics
LHC signatures of Seesaw mechanism

3. Introduction
Part I
Beta decay

5. Neutral, spin ½, mass less than 1% of proton mass
Neutrino

6. Neutral, spin ½, less than 1% of proton mass
Neutrino

8. True picture: An electron antineutrino is emitted from beta decay

10. Detection

11. using neutrinos from a fission reactor
A decision in 1952:
using neutrinos from a fission reactor
A double signature (two flashes of light separated by a few )

12. Lederman, Schwartz & Steinberger 1962 Cowan & Reins 1956 39 years
BNL
Lederman, Schwartz
& Steinberger 1962
Cowan & Reins 1956
39 years
26 years
1995
1988
: Fermi Lab, 2000

13. Neutrino puzzles Solar neutrino Detected neutrino
1/3 Standard Solar Model
1968, Raymond Davis made the first observation of solar neutrino shortfall at Homestake mine
Confirmed by Kamiokande, GALLEX, SAGE and SNO(2001) data
R. Davis
2002

14. Atmospheric neutrino
Expected
Detected

15. Two flavor oscillation
For simplicity, we consider two flavor neutrino mixing and oscillation

16. The oscillation probability for an appearance neutrino experiment:
The conversion and survival probability in realistic units:
Due to the smallness of (1,3) mixing, both solar & atmospheric neutrino oscillations are roughly the 2-flavor oscillation.

17. Flavor Mixing Flavor eigenstates Cabibbo-Kobayashi- Maskawa (CKM)
Weak interaction eigenstates
Mass eigenstates
Flavor eigenstates
Pontecorvo-Maki-Nakagawa-Sakata (PMNS)

18. Experimental bounds Two kinds of hierarchy ( normal & inverted) Normal

19. Mass Generation
SM + right-handed neutrino
Unnatural

20. Radiative mechanisms (S. Weinberg PRD1962, A. Zee PLB1980)
Texture zeros (H. Fritzsch PLB1977, S. Weinberg1977)
Family symmetries (C. Froggat & H. Nielsen NPB1979)
Seesaw mechanisms (P. Minkowski PLB1977)
Extra dimensions (K. Dienes, E.Dudas & T.Gherghetta NPB1999)

21. Seesaw Mechanisms
Type-I : (SM +at least 2 RH Majorana neutrinos )

22. Type-II : (SM +1 Higgs triplet )

23. Type-III: (SM +3 fermion triplet )
Hybrid seesaws: type-(I+II), type-(I+III) …

24. Part II
Type-(I+II) Seesaw
SM + 2 right-handed Majorana neutrinos Higgs triplet
SSB
Diagnolization
Seesaw formula

25. Neutrino Mixing Tri-bimaximal mixing pattern After diagnolization
Harrison et al, 02; Z. Z. Xing, 02; X. G. He & A. Zee, 03
Parameterization
3×3 unitary matrix
Z. Z.Xing, 08
Nearly identity matrix
with

26. Conventional: Testable: Pilaftsis, 92；Kersten et al, 07
W. Chao, Z. G. Si, Z. Z.Xing, S. Zhou 08;
W. Chao, S. Luo, Z. Z. Xing, S. Zhou 07
Flavor symmetry
X. G. He, Y. Y. Keum & R. R.Volkas 06
a. Triplet Higgs observable
b. Heavy Majorana neutrinos testable
c. Neutrinos masses stable

27. Collider Signatures
T. Han & B. Zhang, 06; A. Atre, T. Han, S. Pascoli & B. Zhang,09

28. Define:

30. guarantees a peak around the mass of
>114GeV
CDF Collaboration, 08

31. Thanks for your attention!
Summary
Long Long Ago
Far Far Away
Thanks for your attention!