Can a Lagrangian in QFT be Renormalizable?

Click For Summary
SUMMARY

The discussion centers on the renormalizability of a scalar field theory Lagrangian, specifically examining the term g/φ^2. It is established that the mass dimension of the coupling constant g should be 2(D-1), where D represents the number of space-time dimensions. For D=4, this results in a mass dimension of 6, indicating that the term is non-renormalizable according to power counting rules. The conversation also references the limitations of perturbative renormalization in theories involving negative mass dimensions, such as gravity and the Fermi model of weak interactions.

PREREQUISITES
  • Understanding of scalar field theory in Quantum Field Theory (QFT)
  • Knowledge of mass dimensions and their implications in renormalization
  • Familiarity with perturbative renormalization techniques
  • Basic concepts of effective field theories and energy cutoffs
NEXT STEPS
  • Study the implications of mass dimensions in Quantum Field Theory
  • Learn about effective field theories and their applications in particle physics
  • Research perturbative renormalization methods in QFT
  • Examine the role of negative mass dimensions in non-renormalizable theories
USEFUL FOR

The discussion is beneficial for theoretical physicists, graduate students in particle physics, and researchers focusing on Quantum Field Theory and renormalization techniques.

Giuseppe Lacagnina
Messages
3
Reaction score
1
Possibly very silly question in QFT. Consider the Lagrangian for a scalar field theory.
A term like

g/φ^2

should be renormalizable on power counting arguments. The mass dimension of g should be

2 (D-1)

where D is the number of space-time dimensions.Does this make sense?
 
  • Like
Likes   Reactions: DuckAmuck
Physics news on Phys.org
Isn't there a rule where if the mass dimension is greater than 5, the term is non-renormalizable?
2(D-1)=6, if D=4.
 
As far as I know, a lagrangian term is not perturbatively renormalizable if it involves a coupling with negative mass dimension.
Like it happens for gravity or the Fermi model of weak interactions, which works as an effective theory with an energy cutoff.
 

Similar threads

  • · Replies 49 ·
2
Replies
49
Views
7K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
1
Views
3K