1. Shuo Yang Associated production of the Higgs boson and
a single top quark in the littlest Higgs model
at Large Hadron Collier
Shuo Yang

2. Promblems in SM No fundamental scalars observed in nature
No explanation of dynamics responsible for EWSB
Hierarachy Problem
Trivality Problem
Neutrino mass
Dark matter

3. …… Possible Solutions SUSY Technicolor: TC2 ,top seesaw
Extra Dimensions: flat, wraped
Higgsless Model
Little Higgs ……

4. LHC May Tell Us
what is the nature !

5. Little higgs models
Motivation: hierarchy problem Basic Idea: higgs is a goldstone boson Mechanism: collective symmetry breaking
Littlest Higgs Model
SU(5) SO(5)
[ SU(2)X U(1) ] 2
SU(2)X U(1)

7. We find that in a large part of the parameter space the cross section of th production in
s-channel and t-channel production can deviate largely from the SM prediction.

8. th production signal and background
Our signal is
Backgrounds

10. We find that in a large part of the parameter space the cross section of th production in s-channel and t-channel production can deviate largely from the SM prediction.
Different from the case in SM, in LH model both the cross sections in s-channel and t-channel are larger than that in W-associated process in a large part of the parameter space.
We also consider the signal 4b + l + pt +1jet and backgrounds for the th production. It is found that with 30 fb inverse of integrated luminosity, in the parameter space of C=0.8 and f<1.62, 3sigma deviation can be achieved. With 75 fb inverse of luminosity, 5 sigma deviation can be achieved

11. Thank you !!!

13. Collective symmetry breaking
If there is only g2. the original SU(5) is explicitly broken to SU(3)×SU(2)×U(1), where the SU(3) acts on the first three indices. In this limit, The Higgs doublet h shifts under part of the SU(3), and so it is forbidden from picking up a potential.
The same symmetry argument applies when only g1
is turned on.
The fact that tells us that even when all couplings are turned on, the Higgs does not receive quadratically divergent contributions to its mass-squared at one loop

14. The scalars H and a triplet Ф;
The new gauge bosons ;
The scalars H and a triplet Ф;
The cancellation can also be understood in terms of the Lagrangian in gauge boson mass eignstetes.