RESCHEDULED: Student Colloquium: Kuo-Hsing Tsao
RESCHEDULED DATE TBA
"The Standard Model and Beyond in a Nutshell"
Abstract: The Standard Model (SM) of particle physics can describe almost all the basic forces from the electroweak interaction to the nuclear interaction. However, there are still some intrinsic problems in the SM, including the hierarchy, naturalness and triviality problems. These problems indicate that the SM can only be viewed as an effective theory and there must be theories beyond the SM to be valid at the TeV scale by the Large Hadron Collider (LHC).
Supersymmetry (SUSY), which relates bosons and fermions, is one of the most accepted extensions beyond the SM that emerges at high energy to solve the hierarchy problem. Nevertheless, the real world particles are not degenerate with their superpartners, therefore SUSY must be broken. So far, this is still an open question: what is the mechanism of breaking SUSY?
On the other hand, the cosmic microwave background and structure formation suggests that about 23% of the mass of the universe consists of non-baryonic dark matter, whereas only 4% consists of SM matter. This evidence highly suggests that there must be a theory beyond the SM.
In this talk, the SM and beyond the SM will be introduced. First, the structure of the SM and the concept of Spontaneous Symmetry Breaking and Higgs Mechanism will be reviewed, and finally SUSY and dark matter theory will be followed up as examples of beyond the SM.