LEARNING OUTCOMES

In this course, we study radiative corrections in quantum field theory, which is the theoretical tool that allows us to arrive at a quantitative understanding of high-energy physics.

AIMS AND LEARNING OUTCOMES

After completing this course, the student will be able to

• describe the basic concepts related to renormalisation in quantum field theory;
• apply perturbative techniques to compute observables in quantum field theory;
• compute Feynman diagrams at one loop and interpret the results;
• use symbolic-calculus computer programs (e.g Mathematica) to manipulate compliicated expressions and perform analytic calculations of Feynman diagrams.

PREREQUISITES

The basics of quantum field theory presented in the Theoretical Physics course.

TEACHING METHODS

Blackboard lectures and slides.

SYLLABUS/CONTENT

1. Review of covariant perturbation theory. Feynman diagrams. LSZ formalism.
2. Quantum Electrodynamics as a gauge theory. An example of a QED process at tree-level. Ward-Takahashi identities.
3. An introduction to renormalisation. Loop integrals and their regularisation. Renormalisation schemes. 
4. Radiative corrections in QED at 1 loop: correction to the fermion propagator. Correction to the vertex function and g-2. Vacuum polarisation. 
5. Renormalised perturbation theory. Running coupling. An example of a QED process at next-to-leading order.
6. The infrared region: soft photons. 
7. Towards collider phenomenology: Breit-Wigner approximation and Higgs decay into two photons.
8. Usage of symbolic computation languages (mathematica) to evaluate Feynman diagrams.

RECOMMENDED READING/BIBLIOGRAPHY

Recommended textbook

-M. Schwartz: “Quantum Field Theory and the Standard Model”

Other textbooks

-M. Maggiore: “A modern introduction to Quantum Field Theory”

-S. Weinberg: “The Quantum Theory of Fields Vol 1”

-M. Peskin and D. Schroeder: “An Introduction to Quantum Field Theory”