Gauge Invariance and the Photon Self-Energy Correction

Click For Summary
SUMMARY

The discussion centers on the concept of gauge invariance in quantum electrodynamics (QED) and its implications for photon self-energy corrections. The participant, a second-year M.Sc. student in particle physics, seeks a concise mathematical explanation of how gauge invariance prohibits the photon mass, referencing the Ward identities as a key component. The consensus is that gauge invariance ensures that corrections to the photon mass vanish, as outlined in Peskin's textbook on quantum field theory. This understanding is crucial for grasping the foundational principles of supersymmetry (SUSY) and gauge theories.

PREREQUISITES
  • Quantum Electrodynamics (QED)
  • Gauge Theory Fundamentals
  • Ward Identities in Quantum Field Theory
  • Basic Supersymmetry (SUSY) Concepts
NEXT STEPS
  • Study the derivation of Ward identities in QED
  • Explore the implications of gauge invariance on particle masses
  • Read "An Introduction to Quantum Field Theory" by Michael Peskin
  • Investigate the role of gauge invariance in other gauge theories
USEFUL FOR

This discussion is beneficial for graduate students in particle physics, researchers studying quantum field theory, and anyone interested in the mathematical foundations of gauge invariance and its applications in theoretical physics.

shirosato
Messages
22
Reaction score
0
Short intro.: I'm a 2nd year M.Sc. student in particle physics, with basic quantum field theory and knowledge of the SM and perhaps a bit more. I've read the forums before and tried to find questions/answers that were similar to my own until I decided, "why not just join so I can ask exactly what I want to know?"

Anyway, my question is this: in most introductions to SUSY, they go over the self-energy diagrams for the photon/gauge boson as well as the electron. They then give some simplified integral representing the correction and then saying that gauge invariance guarantees that the correction identically vanishes.

This makes sense knowing some gauge theory (gb mass terms break gauge invariance) and they often cite the Ward identities. Without going through the whole calculation, is there any easy way to explain how gauge invariance forbids the photon mass that is somewhat mathematical without going the whole mile? Writing this, it sounds lazy, but I honestly like to have the minimal non-hand-wavey solution handy at all times.

Shirosato
 
Physics news on Phys.org
I do not know anything else but gauge invariance (classically) and Ward identities (after quantization).
 
Well, upon a bit more reading, its basically outlined in 245-246 of Peskin and it seems that its basically, the gauge invariance of qed manifests itself through the ward identities.
 
That's true
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
58
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K