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0answers
27 views

When did the strong force separate?

Given that Grand Unification may have happened, and inflation is accepted, which of these two scenarios is better accepted; 1) The strong force broke free before inflation, and is somehow causally ...
0
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1answer
29 views

How to understand that the strong nucleair force his reach is so short?

I thought that de radius of the strong force is about 1/r7. The elekctromagnetic and gravity force is with a radius of about 1/r2. I understand that for those last ones twice as far away gives a four ...
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1answer
74 views

Strangeness of elementary particles

What is the property, whose violation led to the assumption of strangeness? Prior to the discovery of strangeness was it assumed that particles that are produced by strong interactions can decay only ...
1
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1answer
54 views

Why do we need the strong interaction if we have Yukawa's meson theory?

How is Yukawa's theory of mesons different from the standard model's strong interaction? I mean if Yukawa's theory is complete then why do we need quarks and gluons?
1
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1answer
77 views

Why do protons not break into quarks?

I know that free a neutron breaks into a proton because a proton has less mass and energy. Then, why do protons not break into quarks, since they have even less energy? Or why do gluons join quarks? ...
13
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2answers
1k views

Why doesn't the color force between two quarks have an inverse square law?

From what I understand the color force between two quarks doesn't decrease with distance. Why is it that the color force doesn't decrease with the square of the distance if there are three dimensions ...
1
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1answer
30 views

Constant in Regge trajectory

The Regge trajectory in QCD is given by $$m=\sqrt{\frac{J}{\alpha}-\alpha_0},$$ where $m$ is the mass and $J$ is the angular momentum of the hadrons, $\alpha=(4\pi\sigma)^{-1}$ is the inverse QCD ...
0
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1answer
85 views

Dark Matter - Why no strong interaction?

Dark Matter shows up in cosmological observations as deviation of velocity of e.g. spiral galaxy arms and so on, so we know it interacts gravitational. We cannot see it, and in the Bullet Cluster you ...
2
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1answer
77 views

What is a dual field?

Can you give me an intuitive, physical understanding of a "dual field"? For example, the Hodge dual of the gluon field strength matrix $F$ is $\tilde{F}_{\mu \nu}=\epsilon_{\mu \nu \alpha \beta} ...
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1answer
91 views

How are gravity and the strong nuclear force related?

Nature is replete with examples of apparently different physical behavior as manifestations of the same phenomenon. So, we can say that we understand something better when this apparent complexity is ...
0
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2answers
84 views

Color Force & Nuclear Force [closed]

I was wondering if the color force and nuclear force are both sub-forces of the Strong Interaction? If so is the Strong Interaction responsible for any other forces?
1
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2answers
86 views

How do protons and neutrons interchange?

I recently read in a book that a nucleon with +1/2 isospin is a proton and if the isospin is changed to -1/2, it is a neutron, so it is the same particle in different states. If a proton has a ...
1
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0answers
37 views

Can non-color-neutral nucleons exist?

In a proton or neutron, one quark is red, another blue, and the last green, making it color neutral. Is it possible for a nucleon to consist of colors rgg, rbb, rrb, etc? If three quarks of such color ...
3
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4answers
120 views

Do neutrons in an atomic nucleus exert strong force on each other?

If they do, then why do we never see clumps of neutrons assembled into "atoms" without protons? Or are neurtons mutually repelled by the strong force?
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vote
3answers
104 views

Why is isospin so useful?

I'm currently reading about isospin in nuclear physics, and I know how to calculate it, and all the math, but I'm actually not sure WHY it is so useful? Can anyone come with some examples where not ...
0
votes
1answer
42 views

Potentials of electrical multipoles vs strong interaction

Are there any reasons of the similarity? As I remember both potentials have the form $$\sim e^{-\alpha r}/r$$ where $r$ is the distance. The comment of Bort below led me to Wikipedia ...
1
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1answer
67 views

What is colour-Coulomb interaction?

In several publications (e.g. http://arxiv.org/abs/1506.06864) a "colour Coulomb interaction" between quarks was mentioned. What kind of interaction is that, is it electromagnetic or strong?
0
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0answers
22 views

What is the entropy of strong and weak nuclear forces? [duplicate]

Can we determine the entropy of strong and weak nuclear forces? If so, what will be the formula to determine the strong and weak force entropy? Thank you :)
3
votes
0answers
119 views

Is there a relationship between force and entropy?

Is there any relation between force and entropy? If any, I would like to know what the equation of this relation will be. What is the entropy of strong and weak nuclear force? Can we determine it? If ...
2
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2answers
174 views

Do hadrons only interact via strong interaction?

According to my revision guide baryon and mesons always interact via the strong interaction. Does this hold for baryon-baryon interactions? meson-meson? Thanks
1
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1answer
242 views

How to tell if a particle interaction is strong/weak?

Problem: Prove that the reaction $p+p\rightarrow p+K^+$ is impossible, where $p=\text{proton}$, $K^+=\text{kaon}$. (Side question: Is there a specific name for a positive Kaon, just like a "positive ...
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1answer
55 views

What does “interact via strong force” mean?

I was just wondering if the words "strong force" and "strong interaction" are interchangeable? Also, these are referring to "strong nuclear force", correct? Then what does it mean for particles to ...
2
votes
1answer
300 views

Electrostatic force has longer range than strong nuclear force?

In my revision guide it says that the electrostatic repulsion between protons in a nucleus has a longer (indefinite, actually) range than the strong nuclear force keeping the nucleons together. So I ...
-1
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1answer
128 views

Why is the strong nuclear force > electrostatic repulsion?

In a nucleus there is a gravitational force between the nucleons and also electrostatic repulsion between the protons, and since electrostatic repulson >> gravitational attraction, it follows that ...
0
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3answers
118 views

What triggers a nuclear chain reaction?

A nuclear fission works by spliting atom's neutrons by neutrons which release energy but how is the chain reaction triggered because at first the nucleus is bond by a strong nuclear force so what ...
3
votes
1answer
114 views

Could the 4 Forces Split Off or “Decay” into Other Forces in the Distant Future? [duplicate]

From my basic understanding of popular-level physics articles and books and such, the 4 forces (Electromagnetism, Gravity, Strong and Weak Force) used to be 1 force in the early universe, then split ...
4
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0answers
116 views

Why is the strong CP term $ \theta \frac{g^2}{32 \pi^2} G_{\mu \nu}^a \tilde{G}^{a, \mu \nu}$ never considered for $SU(2)$ or $U(1)$ interactions?

The Lagrangian one would write down naivly for QCD is invariant under CP, which is in agreement with all experiments. Nevertheless, if we add the term \begin{equation} \theta \frac{g^2}{32 \pi^2} ...
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0answers
45 views

How does the number of neutrons in an atom affect the strong force?

How does changing the number of neutrons (making a different isotope) affect the strong force and therefore the protons and the overall atom?
0
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1answer
195 views

What are the equations for the weak and strong forces?

What are the equations for the strong and weak force, like how for the Electrostatics the equation is $F_c= k*Q*q/(r*r)$. I understand to an extend what the strong and weak forces are. However, I ...
1
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1answer
164 views

Why do the quarks constantly change colors?

In a hadron the quarks constantly change colors.They,then exchange gluons to remain color neutral.For example a red quark becomes blue by emitting a red and anti blue gluon and then the blue quark ...
4
votes
1answer
183 views

Is there such a thing as red - anti red gluon? Why such gluon posssibilities appear in equations?

Gluon properties have puzzled me for quite a while now. I recently learned that there are 8 kinds of gluons. They are kind of represented by 8 linearly independent SU3 matrices. Matrices represent ...
1
vote
1answer
87 views

If isospin is conserved under strong interactions why it is represented by SU(2)?

As far as I know from my readings SU(2) is a representation group of isospin symmetry which shows deep symmetry of the strong force which conserves flavor. Isospin symmetry is broken under weak ...
5
votes
2answers
318 views

Why would two protons repel?

I understand that two protons would repel due to them both being positively charged, however, wouldn't the strong force act on the two protons pulling them together? Would this mean that in this case ...
-1
votes
1answer
1k views

Can we manipulate gravitation? [closed]

When I studied general relativity, my teacher said that what we knew today about gravitation was no better than what we had already known since Newton's time, because so far we could only propose ...
1
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0answers
32 views

Can the strong force be explained by quaternions?

I wonder if the strong force can be explained by quaternions without the use of matrices. I heard that it could, but the source was not reliable.
1
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1answer
216 views

Why is the gravitational force $10^{38}$ times smaller than the strong nuclear force?

Also, why is the weak interaction force $10^7$ times smaller than the strong nuclear force?
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2answers
91 views

Strong force and quantum tunnelling

I am well aware of how quantum tunnelling works and how it is responsible (among other things) for the alpha decay. Inside a nucleon, there are two quarks with the same charge, so they will repel ...
3
votes
1answer
91 views

Are there Planck units for weak or strong “charge”, similar to the electromagnetic Planck charge $\sqrt{4~\pi~\epsilon_0~\hbar~c}~$?

Are there Planck units for "charge" of weak or strong interaction, similar to the Planck unit of electromagnetic charge: $\sqrt{4~\pi~\epsilon_0~\hbar~c}$ ? Are there perhaps direct substitutes, ...
1
vote
2answers
369 views

Why are the dineutron and diproton unbound?

It is known that there is no diproton and dineutron nuclei. Does this mean that two protons or neutrons are not actually attracted to each other? Even if the attraction was weak, wouldn't it cause ...
2
votes
2answers
46 views

The time interval of fundamental interactions?

I extract the below text snippet from our text book: Strong interaction is charge independent.The time interval of such a strong interaction is about $10^{-23} sec$ and it's range is approximately ...
2
votes
1answer
48 views

What theory unifies the electroweak and the strong forces? [closed]

As the title itself suggests, here's my question: What theory unifies the electroweak and the strong forces?
5
votes
4answers
362 views

Radioactive decay - What mechanism decides when an unstable nucleus decays?

My first question on Stackexchange (if it is formatted wrong or something please tell me so I know in future) - here it is: Given an unstable nucleus (exactly which nucleus is not particularly ...
1
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0answers
264 views

What is anti-screening?

In his book "The Lightness of Being" Frank Wilczek (page 48) writes about screening and anti-screening. In screening, a bare charge attracts virtual particles of opposite charge which lessen the ...
2
votes
0answers
44 views

Is Gravity a part of the Strong Nuclear Force? [duplicate]

In episode 7 season 5 of Through the Wormhole, they say that gravity could just be a manifestation of the strong nuclear force and that the force carrier are a pair of Gluons. Is this valid in anyway? ...
10
votes
1answer
200 views

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 ...
1
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1answer
561 views

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?
6
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0answers
96 views

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 ...
8
votes
1answer
225 views

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?
2
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2answers
977 views

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 ...
5
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1answer
222 views

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 ...