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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Fermi momentum vs. nucleon-nucleon momentum
Are there differences between the terms 'Fermi momentum' and 'nucleon-nucleon momentum' and if so, what are they?
I have stumbled across inconsistent terminology in the literature. Some books call the ...
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Momentum distribution of nucleons inside the deuteron (Paris potential)
I am looking for a graph that shows the momentum distribution of nucleons inside the deuteron.
Side note: I know that several models for nucleon-nucleon potentials exist, such as the Paris, Bonn or ...
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How does pion exchange cause protons and neutrons to be attracted to each other? [duplicate]
I read that neutron and protons are attracted through exchanging pions between each other. However, as far as I understand, they are just exchanging a meson, not any force carriers. What causes them ...
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How are $\pi$ Mesons Created in the Residual Strong Interaction?
Watching this episode of PBS Space Time, they run an animation of how pi mesons are exchanged by nucleons as the residual strong interaction to overcome proton electromagnetic repulsion.
https://youtu....
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Is there an experimental set up that would produce a "macroscopic" a weak or strong nuclear force fields?
I was wondering if there is an experimental set up that would produce something equivalent to a classical electromagnetic field for the weak and strong nuclear forces. I know that the those forces are ...
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How exactly does the strong interaction decrease with distance?
So, we all know that the strong force asymptotes but the thing is I've never gotten a good description as to why
Can someone explain;
How the Strong force weakens with distance? I think I have got ...
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What is the mean internucleon distance in a nucleus?
I am finding some conflicting information which is resulting in some confusion when teaching the topic of nuclear physics to high school students.
The residual strong nuclear force has an attractive ...
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How relevant is the electric charge of quarks within hadrons?
Given that each quark flavor has a particular electric charge (i.e., either +2/3 or -1/3): how do these charges effect the internal dynamics of hadrons? Do the attractive and repulsive effects of ...
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Kinetic energy of quarks in a proton
If we say that a proton has a kinetic energy of 50 GeV, can we say that each of the three quarks that compose it have roughly a mean energy of $\approx \frac{50}3=17$ GeV?
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Separation energy of nucleons and Coulomb barrier
My question is related to this topic: Tunneling of alpha particles. Unfortunately it didn't quite solve my doubts.
My professor and the book I'm reading (Particles and Nuclei: An Introduction to the ...
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Collision of two positrons: Is there any "strong force" that binds two positrons together to produce a positron-positron pair with $+2e$?
I want to know if it is possible to hardly collide two positrons with each other to produce a pair with $+2e$. Indeed, I want to know if there is a strong force, similar to those binding protons ...
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Coulombian barrier fission
Protons and neutrons in a nucleus are both in a well of $\sim$ 50 MeV (obviously that depends on the specific nucleus), but the shape of the quantum well is different because there is the Coulomb ...
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What is the significance of the Strong interaction between a pair of Neutrons?
When we are introduced to the Strong Nuclear force, we are told that it prevents the nucleus from flying apart because of the electric repulsion between protons. But there is no such repulsion between ...
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Question about semiclassical approach to QCD
I'm struggling to understand the usefulness of the semiclassical approach to QCD. In particular, by using this approach, we can analyze the vacuum structure of QCD, including theta-vacua, $n$-vacua, ...
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The difference between neutron and proton separation energy of a nucleus
For a given nucleus, why does the value of the neutron separation energy $S_n$ differ from the value of the proton separation energy $S_p$? One of the reasons that is immediately obvious is that the ...
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Why does the Yukawa potential fail for the strong force? [duplicate]
The gluon is a massless particle, so according to the Yukawa potential the strong force should have a $r^{-1}$ potential. However, that is clearly not the case.
Is it because the gluons themselves can ...
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Nuclear physics explained by QCD
I have been studying Particle & nuclear physics and I know that nuclear physics should normally be explained by particle physics. Specifically, I would like to ask if there is any theoretical ...
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Why is the electromagnetic force not an emergent property of the strong force? [closed]
Two up quarks in a proton lead to an imbalance, which results in the proton having the ability to attract electrons. Two down quarks in a neutron lead to balance in the electromagnetic force, leading ...
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Why do the nucleons interact via strong force even though they are color neutral?
Particles that transform non-trivially under color $SU(3)$ interact via strong nuclear force. However, neutrons and protons, despite being color singlets, interact via the strong force. How do we ...
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What is the difference between the strong force and the strong nuclear force?
Is there a difference between the strong nuclear force, and the strong force (without the nuclear in between)? I have heard that the strong nuclear force binds protons and neutrons together, while the ...
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Why are there no particles that ONLY interact via the strong force?
The title speaks for itself really: I noted everywhere I learned about fundamental interactions that there are particles that interact ONLY via the Weak Force (and gravity, if it counts)(e.g. ...
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If isospin is only approximately conserved by strong interaction, why do we never see isospin violation?
Due to the mass difference between the $u$-quark and the $d$-quark, SU(2) isospin symmetry is only an approximate symmetry (even in a universe devoid of weak and EM interactions). This suggests to me ...
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A very basic question about particle (leptons, hadrons) interactions
Suppose a particle reaction $A+B\to C+D$ is allowed in nature. Then, the reactions,
\begin{align}
A&\to \bar{B}+C+D,\\ \bar{C}+\bar{D}&\to \bar{A}+\bar{B},\\ B&\to\bar{A}+C+D,\\& \...
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Can the strong force be expressed as a function of distance between two quarks?
I have two very similar questions about the strong force.
Can the (non-residual) strong force be expressed as a function of the distance, between two quarks and their color charges? Does it depend on ...
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Would a black hole's event horizon split up a hadron into it's constituant quarks? Therefore creating free quarks?
As a thought experiment, say, for the sake of simplicity, we have a meson. This meson, which is traveling near light speed, is traveling towards a black hole. And skirts the event horizon in such a ...
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Can moscovium-299 exist and is it possible to predict how stable it will be? [closed]
Five isotopes of element 115 (moscovium) have been created in the laboratory with atomic weights ranging from 286 to 290, each having a progressively longer half-life, ranging from 20ms to 650ms: ...
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How does a nucleus manage to gather the energy to withstand the constant force applied on it from the protons? [closed]
The force repulsing two protons never goes away, meaning that there is a constant force pushing the protons apart forever. Firstly, where are these protons getting the energy to constant apply this ...
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Can a $\phi$ meson decay into a pair of charged pions ($\pi^-$ and $\pi^+$)?
I understand that $\phi^0 \to \pi^+ \pi^- \pi^0$ is OZI suppressed.
But how about $\phi^0 \to \pi^+ \pi^-$?
Wikipedia doesn't list this decay path but $\phi^0 \to K^+ K^-$. Why? $\phi^0$ is a mixing ...
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EM force or Strong force?
$$
e^- + p \rightarrow \Delta^{++} + e^- + \pi^-
$$
Apparently this reaction is mediated by the EM force. My question is: how do you know it isn't the strong force?
Yes, all the particles have ...
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How relationship between the Euler beta function and the strong nuclear force can be mathmatically be proved?
I'm Korean highschool student and was writing a report about Euler beta function and string theory. And I can know find that Euler beta function is similar with the strong nuclear force equation. But ...
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Why is the mutiplication table for generators in the $su(3)$ algebra so bizarre?
The square of the Gell-Mann matrices $\lambda_1$, $\lambda_2$, and $\lambda_3$ has the bizarre value $2/3 * I + \lambda_8 / \sqrt{3}$.
Is there a simple way to deduce the result from the fact that $\...
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Equation to predict stability, half-life and decay products of atomic nuclei?
Given an atomic nuclei say C-14 or U-233 or anything in-between or outside the range and given the ratio of protons and neutrons in the nuclei, is there a comprehensive equation or set of equations ...
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Is there any something something force other than the electro magnetic force?
Far as I can tell, the force generated by electromagnetic field can be seen as an electrical force or as a magnetic force depending on the observer, i.e., these forces are actually the same phenomenon ...
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Why are nuclei with large numbers of neutrons only stable with correspondingly large numbers of protons? [duplicate]
Large numbers of protons need to be separated by neutrons, otherwise they repel....
But why do nuclei with large of numbers of neutrons only remain stable with a relatively, correspondingly large ...
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Why did Yukawa theorize a neutral pion? Was it necessary or a guess?
At the time, neutrons had just been discovered, but were only needed to explain the extra mass inside nuclei...
We now know that the strong force isn't strong enough to hold positive protons together ...
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Why protons and neutrons don't have less mass than their constituents?
A system of gravitational attracted objects weight less than the sum of their individual masses because it needs energy to move them apart and overcome the gravitational attraction. Same is true for ...
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Strong $CP$ problem and fine tuning
I have worked my way up to and through Srednicki's Quantum Field Theory chapter 94 and was also doing some reading on the internet about the strong $CP$ problem.
Wikipedia's entry on the strong $CP$ ...
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What causes the difference in ranges of forces?
What causes the difference in ranges of forces? In other words, why is it that the weak force acts only at small distances whereas the Coulomb force has a very large range?
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What quantities are associated with the strong and weak forces?
If mass is the quantity associated with gravitation, and charge is the quantity associated with the electromagnetic force, what quantities are associated with the strong and weak forces?
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Do Neutron stars have free quarks?
Do Neutron stars have free quarks? Also Can Quark Stars be formed also due to this reason?
Because of Asymptotic freedom high energy causes quarks to be free but according to the mass-energy ...
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Why would the ratio of the strong nuclear force to electromagnetism be about 137 to 1? What does the fine structure constant have to do with it? [closed]
Is it just another weird coincidence that the strong force is approximately 137 times as strong (at appropriate distances) as the EM force?
Also, when comparing the four fundamental forces and their ...
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How scientists know which particle is/is not influenced by strong force?
Muon is said to be uninfluenced by strong force, unlike pion.
My question is, based on which experiment, scientists determine a particle is influenced by strong force or not?
Edited:
Thank you for the ...
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What is the actual carrier of the strong force? [duplicate]
I have been digging into the particle physics recently and I have found two different answers for this question. First of all, according to Wikipedia the Pion is a meson that acts as the carrier ...
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What happens inside a proton?
This post contains 3 questions but they are very similar.
I saw from this question What's inside a proton? and other websites that protons aren't really made up of three quarks, but a lot of ...
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Is there an energy release from gluon expansion and contraction?
When an electron drops to a lower orbit, energy is released as a photon. Gluons expand and contract in-between quarks, described like springs or rubber bands that have tremendous force when extended ...
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How the non-existance of free quarks is explained by asymptotic freedom?
It is written in page 527 of Schwartz Quantum Field Theory and the Standard Model book that
Due to asymptotic freedom, free quarks do not exist.
I don't understand how asymptotic freedom explains ...
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Glue vs spring, the approach
Why does quantum mechanics use the term "glue" instead of "spring"? Is the strong force wchich keeps quarks together so different from the behavior of springs that they must have a ...
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Are gluon particles analogous to flux tubes?
I've always been told gluons are the force "particles" mediating the strong force. And I've learned that Fluxtubes are what hold quarks together. Are these fluxtubes the "particle" ...
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Do gluons interact via virtual photons?
On a video on Youtube, I commented how a PBS Space Time episode helped me understand the speed of light by calling it the speed of causality. In response, I received the following comment:
"Let'...
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Do pions not interact with other pions via the strong force?
Imagine a positive and negative pion, their only interaction between each other would be due to electromagnetism and the weak force, right? It is not like these two pions can form neutral pions due to ...
