All Questions
Tagged with renormalization propagator
44
questions
1
vote
2
answers
76
views
Understanding Feynman Diagrams in Loop Corrections to the propagator $\phi ^3 $ theory [closed]
I found other posts talking about the same chapter in the same book, but none of them were exactly about what I am asking here.
In Srednicki's chapter 14 (Loop corrections to the propagator), we are ...
1
vote
0
answers
58
views
Unitarity and renormalizability in $R_\xi$ and 't Hooft gauge
Consider the massive propagator with gauge fixing $\frac{1}{2a} (\partial A)^2$
$$
\Delta_{\mu\nu}=-i\left[\frac{g_{\mu\nu}}{k^2-m^2}-\frac{k_\mu k_\nu}{m^2}\left(\frac{1}{k^2-m^2}-\frac{1}{k^2-am^2}\...
- 534
2
votes
1
answer
51
views
Renormalization condition for field strength renormalization
I am studying $\phi^4$ theory and so far I understand the mass and coupling constant renormalizations. In these theories, once we expand a diagram in perturbation theory we "cancel" the ...
- 3,350
3
votes
0
answers
84
views
Peskin & Schroeder Chap 7.1: Two-point correlation function in Field Strength renormalization
I have some simple questions. I was going through Peskin & Schoeder Introduction to QFT, trying to understand the two-point correlation function on interacting theory (Chapter 7.1) for the case $x^...
- 43
8
votes
1
answer
413
views
Fradkin renormalization group propagator integral
I am studying Fradkin's lecture notes on advanced field theory, and in the section on Wilson RG he has a list of integrals of the propagators of the fast fields. One of such integrals is:
$$
\int d^D ...
- 61
2
votes
0
answers
149
views
Pauli-Villars regularization and self-energy
In the calculation of the electron self-energy in QED (one-loop level), there is a UV and IR divergent integral that needs to be regularized. A common choice for the regularization is the Pauli-...
- 1,989
1
vote
1
answer
91
views
Peskin and Schroeder Pg. 228: Expanding resummed propagator around the physical pole
I am having difficulty wrapping my head around this particular statement and equation (7.44) on pg. 228 of P&S,
I think I understand that "~" sign here is trying to denote at under $p^0 ...
- 141
2
votes
1
answer
191
views
Why does it make sense to do Dyson Resummation with first-order 1PI-diagrams?
This is somewhat related to This question.
The way I understand renormalisation (e.g of the mass) is that we consider the loop-corrections order by order in the coupling constant. If we then consider ...
3
votes
2
answers
495
views
Renormalization of the photon propagator at loop-level
I am trying to understand the photon propagator renormalization procedure, followed in M. Srednicki's book Quantum Field Theory. Specifically, I am reading Chapter 62, titled "Loop Corrections in ...
- 3,992
2
votes
2
answers
191
views
How do we know there will be enough counterterms to renormalize a theory?
I am wondering if it is always certain that there are enough counterterms to renormalize a renormalizable (e.g. non-negative mass dimension of coupling constant) theory. Through some methods such as ...
- 2,122
3
votes
0
answers
130
views
Unstable particle problem in Peskin and Schroeder
I'm confused by the meaning of the field strength renormalization on page 237 of Peskin and Schroeder. In it, they define the physical mass $m$ of the unstable particle by
$$m^2-m_0^2-\operatorname{Re}...
- 2,122
5
votes
1
answer
281
views
Trouble understanding Wilsonian renormalization
I have been attempting to go through Chapter 12 of Peskin & Schroeder, but I have been having a very tough time. In particular I have been having trouble following this chapter much beyond page ...
- 3,350
6
votes
0
answers
142
views
Field strength renormalization constant $Z$
Matrix elements of the interacting real scalar field $\varphi(x)$ differ from the matrix elements of the in-(scalar) fields (which follow the free Klein-Gordon equation and are the asymptotic fields ...
- 9,778
3
votes
1
answer
129
views
Renormalization constant in unstable particle propagator
On Peskin & Schroeder's QFT, section 7.3, the book discusses the unstable particle.
Before (7.57), the book gives the formula of a scalar particle propagator
For unstable particle, the book ...
- 1,421
1
vote
3
answers
414
views
Yukawa decay at one-loop
I am trying to calculate the amplitude for a decay $\phi \to e^+e^-$ under a Yukawa interaction $\mathcal{L}_I = -g\phi \bar{\psi}\psi$ to one-loop order (with massless fermions for simplicity).
If I'...
- 23