Week 8, Thursday

Four-dimensional $\phi^4$ Theory at One Loop

We looked at the divergences in the one-loop diagrams in the four-dimensional $\phi^4$ theory, and how they are renormalized. This requires mass, coupling constant, and field renormalization.

I concluded with pictures of the running coupling constants in the Standard Model:

• Gauge coupling constants without supersymmetry
• Gauge coupling constants with supersymmetry meet in a point. Does it mean something?
• Quartic Higgs coupling runs to smaller and possibly negative values at high energies.

TODO: type my lecture notes