All Questions
6
questions
2
votes
1
answer
169
views
Does pionium decay in massless QCD?
The bound state of ${\pi}^+ {\pi}^-$ is called Pionium.
Is Pionium an Electromagnetic bound state or a Strong Force one? then Why?
Does such a bound state last forever if one works in QCD with ...
- 1,268
14
votes
4
answers
2k
views
How does the strong force increase in attraction as particles move farther away?
I have heard that the strong force can be imagined similar to a rubber band, where the farther you extend the ends, the harder they pull themselves back together. My question is how? From what it ...
- 451
0
votes
0
answers
68
views
How is strong coupling constant measured through deep inellastic scattering (DIS)?
is deep inelastic scattering a process? and how is it (DIS) used to measure strong coupling constant?
the traditional method of measuring $α_S$ in deep inelastic scattering is from the strength of ...
- 141
-1
votes
1
answer
583
views
How does mass of the exchange particles affect the range of a force? [duplicate]
I read an article asserting that nuclear force is a short range force because of gluon's mass, and EM force is a long range force because photons massless.
I also want to know, why quantum ...
- 455
5
votes
2
answers
324
views
Why and how does the term $\frac{\theta}{32\pi^2}F_{\mu\nu a}\tilde{F}^{\mu\nu a}$ induce electric dipole moment of the neutron?
It is well-known that the operator $$\delta \mathcal{L}_{QCD}=\frac{\theta}{32\pi^2}F_{\mu\nu a}\tilde{F}^{\mu\nu a}$$ violates CP, it can contribute to the neutron electric dipole moment, $d_n$. For ...
- 26.8k
8
votes
1
answer
2k
views
Why does the quarks binding energy add mass to nucleons instead of reducing it? [duplicate]
The mass of nucleons is bigger than the sum of the masses of its constituent quarks. I understand that it's because you have to take into account the binding energy of these quarks.
What I don't ...
- 4,827