PHY578 Effective Field Theories for Particle Physics

The focus of the course is on effective field theories (EFT) in the context of particle physics. EFTs provide a framework to systematically disentangle effects due to different scales. This will be discussed both in general terms and with specific phenomenological applications in mind.

We will start by introducing the core ideas of constructing EFTs and consider cases where the effect of heavy particles or large-scale modes are integrated out. Concepts like decoupling and matching as well as applications of the method of regions and the renormalisation group will be covered.

In the second part of the course several concrete examples of EFTs are presented. They allow for a consistent description of a wide variety of physical systems, from bound states with heavy quarks, jets in collider physics, non-perturbative  strong interaction at low energies, to effects of heavy physics beyond the Standard Model.

Main topics:

• Introduction to Effective Field Theories
• Decoupling and matching
• Renormalization-group resummation
• Example of EFTs
  • Heavy Quark Effective Theory (HQET)
  • Non-Relativistic QCD and QED (NRQCD and NRQED)
  • Soft-Collinear Effective Theory (SCET)
  • Standard Model and Low Energy Effective Theory (SMEFT and LEFT)
  • Chiral Perturbation Theory

Lecture notes for first part I (PDF, 2 MB)

Lecture notes for first part II (PDF, 1 MB)

• A. Manohar, Introduction to Effective Field Theories, Les Houches Lect. Notes 108 (2020).
• S. Scherer, M. R. Schindler, A Primer for Chiral Perturbation Theory, Lect. Notes. Phys. 830 (2012).
• A. Pich, Chiral Perturbation Theory
• G. Colangelo and G. Isidori, An Introduction to ChPT  
• A. Manohar, Effective Field Theories
• T. Becher, A. Broggio and A. Ferroglia, Introduction to Soft-Collinear Effective Theory, Lect. Notes Phys. 896 (2015)
• M. Neubert, Heavy-Quark Effective Theory, Subnucl. Ser. 34 (1997)