Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with quantum-field-theory
Search options not deleted
user 240866
Quantum Field Theory (QFT) is the theoretical framework describing the quantisation of classical fields which allows a Lorentz-invariant formulation of quantum mechanics. QFT is used both in high energy physics as well as condensed matter physics and closely related to statistical field theory. Use this tag for many-body quantum-mechanical problems and the theory of particle physics. Don’t combine with the [quantum-mechanics] tag.
0
votes
0
answers
69
views
What does vanishing critical mass exponent mean?
I would like to understand the reason behind the vanishing critical mass exponents. I've written a program that calculates the fixed points and then the eigenvalues corresponding to the fixed point so …
- 3,494
3
votes
0
answers
77
views
Can someone explain why the effective potential should be IR cutoff independent?
I'm studying renormalization in my bachelor but there is something I don't understand:
In $\phi^4$ scalar field theory, What does it mean that effective potential is depending on the cutoff? and Why …
- 3,494
1
vote
0
answers
240
views
Definition of "particle" in QM and QFT
To sum up;
In Classical Physics, particles can be defined as
... particles (or corpuscule in older texts) is a small localized object to which can be ascribed several physical or chemical propertie …
- 3,494
7
votes
Accepted
Does the Pauli exclusion principle apply to one fermion and one antifermion?
As you stated, no two fermions or anti-fermions can occupy the same state. And here by "state" we mean all quantum numbers defining the properties of our particle. So since electric charge for e.g. el …
- 3,494
0
votes
1
answer
196
views
How does the Nambu-Goldstone mode explain the absence of parity doubling?
I've been doing some reading about chiral symmetry breaking since it was not touched in my particle physics course
I found these slides
As explained in the above link, if we take $|\psi \rangle$ as th …
- 3,494
1
vote
0
answers
151
views
LSZ reduction formula relation
LSZ formula gives a relation between the scattering amplitudes and correlators as
$$\langle f |i \rangle = (-i)^{m+n}\int \Pi_{i=1}^m d^4x_, e^{ik_i'x_i (\Box_{x_i} -m^2)}\Pi_{j=1}^n d^4x_, e^{ik_j x_ …
- 3,494
0
votes
1
answer
158
views
Fermi's theory and left-handed anti-neutrino
I calculated the $\mu \rightarrow e^- + \nu_{\mu} + \bar{\nu}_{e}$ both in Fermi's theory (V-A) and Intermediate Vector Boson theory and IVB at first order seems to match with Fermi's theory which is …
- 3,494
0
votes
1
answer
887
views
Confusion with $S$-matrix of Bhabha scattering
Here are the two Feynman diagrams that corresponds to $e^- + e^+ \rightarrow e^- + e^+$ processes: electron positron scattering and electron positron annihilation respectively.
I can clearly see the …
- 3,494
0
votes
0
answers
403
views
Higgs boson propagator and current terms
I have been trying to get the scattering amplitude for $u+u \rightarrow u+u$ where $u$ are a specific type of lepton.
From the following diagrams, I can write the Feynman amplitudes as
$$\mathcal{M_1 …
- 3,494
5
votes
2
answers
328
views
Symmetry factors in two interacting fields
Red and blue colored lines represent the two different fields.
At 1st order, by the exchange of the blue legs and red legs we get $\frac{1}{4}$ factor and in one of the 2nd order term drawn above, fr …
- 3,494
2
votes
2
answers
473
views
Exact propagator - 1PI diagrams
Above diagram can be written in terms of series:
$$i\Delta = -\frac{i}{p^2 + m^2} + \Big(-\frac{i}{p^2 + m^2}\Big)(i\Pi)\Big(-\frac{i}{p^2 + m^2}\Big)+ \Big(-\frac{i}{p^2 + m^2}\Big)(i\Pi)\Big(-\frac …
- 3,494
1
vote
0
answers
333
views
Spontaneous Symmetry Breaking / Explicit Symmetry Breaking [closed]
I'm trying to understand the SSB and explicit symmetry breaking.
If we have a complex scalar field theory with Mexican hat potential,
$$\phi(x)=\frac{\sigma(x)}{\sqrt{2}}e^{i\Pi(x)/v}$$
choice of the …
- 3,494
1
vote
1
answer
195
views
$\nu_e \bar{\nu_e} \rightarrow e^- e^+$ confusion
Interacting part of the $SU(2)_L$describing the Higgs and fermionic sector with one family
$$\mathcal{L}= \bar{l}_Li\not Dl_L+\bar{e}_Ri\not\partial e_R+ \bar{\nu}_Ri\not\partial\nu_R - (y_{\nu}\bar{l …
- 3,494