Starting week 45, 2023 – every Tuesday from 10am - 12pm in room B1 – ending week 51, 2023
The absence of any new high-energy resonances beyond the Higgs boson at the Large Hadron Collider suggests
the presence of a mass gap up to the scale of new physics, whatever it might be. Despite this possible gap, we
can look for hints of new physics in various precision measurements, which can probe much higher energy scales
than what can be realized on shell in current experiments. The Standard Model Effective Field Theory (SMEFT) is
a very useful framework for interrogating such effects of new high-energy physics on experiments at lower
energies.
This course introduces the SMEFT as an important tool in the search for physics beyond the SM. We will begin by
covering the basic ideas behind using Effective field theories (EFTs) and outline their use in the pipeline between
high-energy physics models and predictions for low-energy observables. We will then proceed to cover the two
main uses of the SMEFT: In the so-called "bottom-up" approach, the SMEFT is used to parametrize possible
deviations from the SM, which can be used to search for consistent beyond-the-SM (BSM) explanations for
experimental anomalies and inform model building. The "top-down" application of SMEFT lies in the computation
of low-energy observables from high-scale BSM models. This is easier when using SMEFT because one can
reuse part of the computations. At the same time, using an EFT approach is required for obtaining accurate
results.
To illustrate the SMEFT use cases, we will draw on real-world examples from recent literature. Along the way, we
will discuss the importance of the renormalization group and discuss how to perform EFT matching beyond the
leading order in the perturbative expansion. The ideas and techniques taught in this course are under continual
development in the BSM community and seem certain to play an important role in BSM phenomenology for the
foreseeable future.
Learning results of the course:
The objective of this course is to provide the students with a detailed understanding of the role of effective field
theories in physics beyond the Standard Model. A particular emphasis will be put on the role of the
renormalization group effects and their calculation using perturbation theory. The participants will learn what goes
into the EFT workflow and how to connect high-energy new physics with low-energy observables.
Lecturer:
Anders Eller Thomsen