Questions tagged [strong-force]
The strong force or interaction is responsible for the confinement of quarks inside hadrons and the binding of nucleons inside a nucleon, and it is described by the gauge theory of QCD. It provides most of the mass of ordinary matter, which is dominated by the nucleons, proton and neutron: over 99% of the mass of these is attributable to the strong-force field energy. Use where technical details of QCD are not warranted.
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Could the universe have non-vanishing net colour charge?
I've heard that the strong force doesn't decrease in strength with increasing distance, and that's why quarks must be confined within hadrons. But could there be, say, a single quark out there, so ...
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Strength of strong nuclear force vs distance?
Is there at least an approximation of the decrease in strong nuclear attraction vs distance from the center of the nucleus?
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From $U(3)$ to $SU(3)\times U(1)$ Color symmetry. There is a "gluon" photon-like?
Suppose that $U(3)$ was the gauge group. We can decompose this as
$U(3)=U(1)\times SU(3)$,
which implies that in addition to the $SU(3)$ that has eight generators corresponding to eight gluons, there ...
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Why $SU(3)$ and not $U(3)$?
Is there a good reason not to pick $U(3)$ as the colour group? Is there any experiment or intrinsic reason that would ruled out $U(3)$ as colour group instead?
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Difference between weak and strong interactions?
This was a statement given in my class:
"Strangeness is conserved in the strong and electromagnetic interactions, but not in a weak interaction "
But could someone please tell me how we ...
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What's a geometric explanation for exponential-falloff fundamental forces?
Gravity and electromagnetism are inverse-square laws. This makes geometric sense -- if you build a spherical shell around a lamp then a shell with twice the radius has four times the surface area and ...
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Protons and Electrons Occupying the Same Space
When it comes to atoms electrons can't fall into the nucleus, which besides the off hand uncertainty explanation, I'm not sure which force prevents them from falling into the nucleus. I thought I ...
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Strongly coupled electromagnetic force
What would be defining about a strongly coupled electromagnetic force? Would it mean that separating two oppositely charged particles makes another particle-antiparticle pair, rather than continuing ...
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Fundamental difference between neutron and proton
As I try to understand the elementary particles, I was reading strong interactions and Isospin from a book. Then I came across this:
Thus, the strong interactions do not distinguish between a ...
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Internuclear Binding Force: Experimental geometric detail
I am looking for the most precise currently available deuterium potential energy curve (generated purely by experimental data) on the nucleon-nucleon scale. This is crucial. I need a radial cross-...
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Are there any serious alternatives to QCD nowadays?
I've read several posts here where people talk about the history of the developement of the theory of strong interactions. And they mention Regge theory, pomerons, S-matrix and so on.
I'm confused ...
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Proof that QCD is the theory describing strong interactions?
I would like to ask what are the experimental evidences that led to the conclusion that QCD is the right theory to describe strong interactions. I know that some of the key point are the decay of $\...
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How does the nature of nuclear force change between attractive or repulsive based on distance?
I know that the nuclear force is responsible for binding the protons and neutrons together in the nucleus. The force is powerfully attractive at small separations and rapidly decreases as the distance ...
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How does flux tubes between quarks bind them together?
If you have, say, a proton it has gluon field fluctuations around it. Those flux tubes between the quarks suppresses the gluon field fluctuations and create a true vacuum between them(correct me if I'...
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What do we know about the interactions between the protons and neutrons in a nucleus?
In a nucleus, the strong nuclear force causes interactions between protons and protons, between neutrons and neutrons, and between protons and neutrons. What do we know about this interaction?
...
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Why do nucleons feel a repulsive force when less than 1 fm?
My Modern Physics textbook by Taylor states that when nucleons are less than 1 fm apart, there is a strong repulsive force between them. I am fairly certain that it is not the Pauli Exclusion ...
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What led to the electroweak and strong forces splitting?
Is the reason for the split believed to be spontaneous symmetry breaking? If so, did SSB occur because the Universe was cooling rapidly from extremely high temperatures?
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Why don't neutrons in a nucleus decay? [duplicate]
When I asked here why neutrons in nucleus (with protons) don't decay I was told that it would require energy for the neutron to decay, it wouldn't give energy. And since that wasn't really what I ...
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Alpha decay, why does it occur? [duplicate]
I was reading about alpha decay and why it happens.
The strong force holds protons and neutrons together, but I don't get why does an atom emit helium nucleus when it has too many protons&...
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Why can the Euler beta function be interpreted as a scattering amplitude?
The Wikipedia article on the Veneziano Amplitude claims that the Euler beta function can be interpretted as a scattering amplitude. Why is this?
In another word, when the Euler beta function is ...
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Does strong interaction care about mass? (+ Isospin question)
So in the journey of trying to understand more about the strong interaction I have encountered some passages linking mass with strong interaction. Like from Greiner and Müller Quantum Mechanics - ...
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Why strong and weak forces are short range? [closed]
Why are the strong and weak nuclear forces short range?
Are quarks confined or welded together?
Why are elementary particles confined at short range?
Or is color confinement color welding?
the ...
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Is there any relation between weak and strong forces, similar to electric and magnetic forces?
Is it possible to unify the strong, weak, electric and magnetic field just by Maxwellian-type equations?
(Maxwell by adding a small change - unified electric and magnetic field, then Einstein's ...
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Fusion vs. Fission
I understand why fission generates large amounts of energy when the nucleus is split, but then why does fusion generate such large amounts of energy. If fission releases energy when some mass is lost ...
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Stable Nuclei - Deviation from equal protons and neutrons
While studying the semi-empirical mass formula for nuclei, I came across an "asymmetry term" whose function, as far as I understand, is to build in the fact that nuclei "prefer" to have equal numbers ...
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Why is a pion so light compared to a neutron or proton?
A pion is made out of a pair of up and/or down quarks. A neutron or proton is three up or down quarks. So naively I'd expect a pion to be about 2/3 the mass of a nucleon.
In fact it's less than 1/6 ...
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Which pion is mediator in nucleon-nucleon interaction
In nucleon-nucleon interactions of n-n, p-p, n-p how do you determine which pion is the mediator?
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Does the strong (nuclear) force ever contribute to decay?
Does the strong (nuclear) force ever contribute to decay ?
Or is the weak nuclear force the only decaying force ?
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Bound states in QCD: Why only bound states of 2 or 3 quarks and not more?
Why when people/textbooks talk about strong interaction, they talk only about bound states of 2 or 3 quarks to form baryons and mesons?
Does the strong interaction allow bound states of more than 3 ...
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How positively charged protons remain glued to each other while they should repel each other out of nucleus? [duplicate]
Possible Duplicate:
Protons' repulsion within a nucleus
How positively charged protons remain glued to each other while they should repel each other out of nucleus?
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We know that the protons in a nucleus are positively charged. So why does the nucleus stay intact? [duplicate]
We know that the protons in a nucleus are positively charged, whereas the neutrons do not possess a charge; we also know that unlike charges attract. So why does the nucleus stay intact, even though ...
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Strong force, where is the separation?
In class I was given a diagram like this: (albeit without the electrostatic force line)
(source: boredofstudies.org)
However, the teacher told us the nucleons are typically separated when the ...
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Do color-neutral gluons exist?
If I'm correct a quark can change color by emitting a gluon. For example a blue up quark $u_b$ can change into a red up quark by emitting a gluon:
$$u_b \longrightarrow u_r + g_{b\overline{r}}$$
(Here,...
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Tunneling of alpha particles
Consider this explanation of the alpha decay: It says
The Coulomb barrier faced by an alpha
particle with this energy is about 26
MeV, so by classical physics it cannot
escape at all. Quantum ...
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Protons' repulsion within a nucleus
Do the protons inside the nucleus repel each other by the electrostatic force? If they do, why doesn't the repulsion drive the protons apart so that the nuclei get disintegrated?
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Is there an equation for the strong nuclear force?
The equation describing the force due to gravity is $$F = G \frac{m_1 m_2}{r^2}.$$ Similarly the force due to the electrostatic force is $$F = k \frac{q_1 q_2}{r^2}.$$
Is there a similar equation ...
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