**Office: **M2042 Physics Research Bldg

**Office Hours: ** Tuesday 2:00 - 3:00 pm, Thursday 10:00 - 11:00 am

**Course Meets: **Mondays Wednesdays 10:30 am - 12:18 pm, Smith Lab, room 1180.

**Grader:** Zhi Qiu

***** First Class Meets January 4, 2012 *****

**Fall quarter:**we will learn how to treat fields (not particles!), such as electric and magnetic fields from the E&M class, as quantum-mechnical objects (how to "quantize" them). You'll see that this is not your mother's quantum mechanics! We will study the most important language of quantum field theory - the language of Feynman diagrams. Formal topics are:- Classical field theory
- Lorentz and Poincare groups and classification of fields
- Canonical quantization of free scalar, Dirac and electromagnetic fields
- Correlators in free field theory, Feynman propagator
- Interacting fields and Feynman diagrams
**Winter quarter:**We will use Feynman rules to calculate cross sections for some (lowest order in the coupling constant) scattering processes. We will then find out that much of what we have learned in the Fall quarter was lies, as Feynman diagrams at the higher (loop) orders in the coupling often lead to sick infinities. We will learn how to regulate the infinities (make them finite) and how to do them away altogether using the process or renormalization, thus saving the day. Topics will be:- Cross sections, S-matrix, and the LSZ reduction formula
- Quantum Electrodynamics (QED): cross section calculations for tree-level processes
- Radiative corrections, dimensional and Pauli-Villars regularizations, Ward identity
- Renormalization group, renormalization of QED and scalar theories, running coupling constant

**Spring quarter:**We will start by learning how to quantize the fields using Feynman's functional integrals, which is a beatiful alternative to canonical quantization. We will then cover non-Abelian gauge theories, which are the backbone of the Standard Model of Particle Physics, as they explain both the strong and the electroweak interactions. We will study the theory of strong interactions - quantum chromodynamics (QCD). In the process we will have another scare as we will discover another sick infinity, the so-called Landau pole, and will learn why Landau did not believe in field theories. We will see why Landau's worries were wrong for QCD, but probably right for QED. We will then explore some special topics in Quantum Field Theory, several of which are listed below. Topics are:- Functional integration
- Non-Abelian gauge theories, Faddeev-Popov ghosts
- Quantum Chromodynamics (QCD): asymptotic freedom and Landau pole, e^+e^- annihilation, Deep Inelastic Scattering (DIS) and parton model
- Some special topics on demand: possibly quantum anomalies, instantons and other topological objects in field theory, DGLAP evolution, small-x physics and parton saturation, Electroweak theory - the choice is up to you guys

- M. E. Peskin, D. V. Schroeder - An Introduction To Quantum Field Theory, Google Books

- L. H. Ryder - Quantum Field Theory, Google Books
- C. Itzykson and J.-B. Zuber - Quantum Field Theory, Google Books
- P. Ramond - Field theory: a modern primer, Google Books
- S. Weinberg - The Quantum Theory of Fields, Google Books volume 1, volume 2, volume 3
- G. Sterman - An Introduction to Quantum Field Theory, Google Books

- H. Georgi - Lie Algebras in Particle Physics, Google Books

- Review of the first quarter + some odds and ends
- Cross Sections, S-Matrix, and the Reduction Formula
- Quantum Electrodynamics (QED): Tree-Level Processes
- Regularization and Renormalization

(Solutions are password protected, they are for the use of OSU students and faculty only: if you are an OSU student or a faculty member and are interested in accessing them please write to me.)

- HW 1 (due Monday, January 23 --> deadline changed to Monday, January 30) -- Solution 1
- HW 2 (due Monday, February 13 --> deadline changed to Wednesday, February 15) -- Solution 2
- HW 3 (due Monday, February 27) -- Solution 3
- HW 4 (due Monday, March 12 --> deadline changed to Thursday, March 15) -- Solution 4

Yuri Kovchegov