All Questions
Tagged with quantum-field-theory particle-physics
223
questions
95
votes
6
answers
18k
views
What is more fundamental, fields or particles?
My confusion about quantum theory is twofold:
I lack an adequate understanding of how the mathematics of quantum theory is supposed to correspond to phenomena in the physical world
I still have an ...
- 1,141
182
votes
5
answers
25k
views
Gauge symmetry is not a symmetry?
I have read before in one of Seiberg's articles something like, that gauge symmetry is not a symmetry but a redundancy in our description, by introducing fake degrees of freedom to facilitate ...
- 17.1k
39
votes
2
answers
13k
views
How does the Higgs mechanism work?
I'm not a particle physicist, but I did manage to get through the Feynman lectures without getting too lost.
Is there a way to explain how the Higgs field works, in a way that people like me might ...
- 17.1k
73
votes
7
answers
17k
views
Why isn't Higgs coupling considered a fifth fundamental force?
When I first learned about the four fundamental forces of nature, I assumed that they were just the only four kind of interactions there were. But after learning a little field theory, there are many ...
- 1,070
21
votes
7
answers
5k
views
Why do physicists believe that particles are pointlike?
String theory gives physicists reason to believe that particles are 1-dimensional strings because the theory has a purpose - unifying gravity with the gauge theories.
So why is it that it's popular ...
- 227
21
votes
2
answers
14k
views
Virtual photons, what makes them virtual?
The wikipedia page "Force Carrier" says:
The electromagnetic force can be described by the exchange of virtual photons.
The virtual photon thing baffles me a little. I get that virtual particles ...
- 471
33
votes
2
answers
11k
views
The concept of particle in QFT
I never learnt QFT and I apologize for my (probably) elementary question. Somebody told me that in QFT a particle is viewed as an irregularity in the field.
On the other hand, in an article in ...
- 6,896
22
votes
2
answers
4k
views
Virtual particles and physical laws
Recently, I was reading about Hawking Radiation in A Brief History of Time. It says that at no point can all the fields be zero and so there's nothing like empty space(quantum fluctuation etc.). Now, ...
- 1,804
14
votes
1
answer
8k
views
Is the electromagnetic force responsible for contact forces? [duplicate]
It is commonly stated that there are four fundamental forces, or interactions, in nature. It is natural to consider which of those is responsible for the normal force we meet in elementary physics. ...
- 243
48
votes
2
answers
17k
views
Weak force: attractive or repulsive?
We are always told that there are the four fundamental forces or interactions of nature: gravitation, electromagnetism, and the weak and strong forces. We know that gravitation is attractive, that ...
- 975
58
votes
1
answer
7k
views
Why are particles thought of as irreducible representations, in plain English?
I'm a PhD student in mathematics and I have no problem in understanding what irreducible representation are. I mean that the mathematical side is not a particular problem. Nevertheless I have some ...
- 944
27
votes
4
answers
7k
views
Decay of massless particles
We don't normally consider the possibility that massless particles could undergo radioactive decay. There are elementary arguments that make it sound implausible. (A bunch of the following is ...
user4552
10
votes
1
answer
1k
views
Lie algebra of axial charges
Starting from the lagrangian (linear sigma model without symmetry breaking, here $N$ is the nucleon doublet and $\tau_a$ are pauli matrices)
$L=\bar Ni\gamma^\mu \partial_\mu N+ \frac{1}{2} \partial_\...
- 103
46
votes
1
answer
2k
views
Resolving Conflicting Reports on Fermilab $g-2$ Results
Today it was announced that the Fermilab measurements of the muon's gyromagnetic ratio are in disagreement with the Standard Model with a statistical certainty reported at 4.2 sigma [1, 2], raising ...
- 3,710
8
votes
2
answers
1k
views
Making precise the statement "particles are excitations in a quantum field"
I've been trying to self teach QFT lately. I find that the basic physical idea makes sense, and I can keep up with the mathematical formalism without too much trouble, but I'm having trouble ...
- 28.3k