Counterterms
Quantum Field Theory · Part 6
217 KB10 sections4 key equationsLaTeX typeset
Table of Contents
- 1.3.1 Bare vs. Renormalized Parameters
- 2.3.2 Example: φ⁴ Theory
- 3.3.3 One-Loop Renormalization of φ⁴
- 4.3.4 Counterterms in QED
- 5.3.5 Ward Identity and Charge Renormalization
- 6.3.6 Systematic Renormalization: BPHZ
- 7.3.7 Physical Interpretation
- 8.(a) Tadpole Diagram
- 9.(b) Self-Energy
- 10.(c) Vertex Correction
Key Equations
$$\mathcal{L} = \frac{1}{2}(\partial_\mu\phi_0)^2 - \frac{1}{2}m_0^2\phi_0^2 - \frac{\lambda_0}{4!}\phi_0^4$$
$$T = -\frac{i\lambda}{2} \int \frac{d^dk}{(2\pi)^d} \frac{1}{k^2 - m^2} = -\frac{\lambda m^2}{32\pi^2}\left(\frac{2}{\epsilon} - \ln\frac{m^2}{\mu^2} + \text{finite}\right)$$
$$\delta\lambda = \frac{3\lambda^2}{16\pi^2\epsilon} + \text{finite}$$
$$\delta Z_2 = -\frac{e^2}{8\pi^2\epsilon} + \text{finite}$$
Equations are rendered with MathJax in the PDF with professional LaTeX typesetting.
Course Context
This PDF is part of the Quantum Field Theory course on CoursesHub.World. Free online course in Quantum Field Theory (QFT). 8 parts covering classical field theory, canonical quantization, path integrals, QED, non-Abelian gauge theories, renormalization, the Standard Model,...