All Questions
Tagged with quantum-chromodynamics mesons
29
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What is vector meson dominance and why is that related to QCD having a repulsive potential?
At long distances QCD is said to give rise to attractive force between nucleons by pion exchange and to give rise to repulsive force at short distance mediated by vector mesons. Is there a ...
- 255
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62
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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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Mass of the kaon (1460)
When looking at the particle listing in PDG most of the hadron masses and excitation include an experimental error. But this is not the case for the Kaon (1460), does anybody know why? This means the ...
- 21
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Meson-Meson Scattering Data
Recently, I have been interested in the scattering amplitudes of mesons in the high-energy fixed-angle regime. I have come across a simple result, due to Brodsky et al., that predicts the scaling of ...
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Structure functions for mesons
I was researching about structure functions and understand how it's a probability density function that describes the distribution of quarks inside hadrons. However, since mesons also have quark gluon ...
- 625
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How Does QCD Explain Nuclear Fission?
This question is brief and simple. As a layman, it is my understanding that QCD (Quantum Chromodynamics) explains the nuclear force as a "residual" force, mediated by pions (mesons), which ...
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In the history of the development of the standard model was there a version in which quark-antiquark pairs or flux tubes were the fundamental particle [closed]
Based on the observations of color confinement and no free quarks, I'm wondering if instead of a having quarks as fundamental particles, during development of the Standard Model was there ever a ...
- 518
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251
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Can mesons be in $b \overline{b}$, $r \overline{r}$, $g \overline{g}$ states?
Can a meson be in a pure $b \overline{b}$, $r \overline{r}$, $g \overline{g}$ state or does it have to be in the $\frac{1}{\sqrt{3}}\left(b \overline{b}+r \overline{r}+g \overline{g}\right)$ state?
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Meson masses difference
I am reading some group theory applied to QCD and they show how by using the lightest 3 quarks in the $l=0$ state we get 9 pseudoscalar mesons and 9 vector mesons. The difference in masses between the ...
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Why is a quarkonium any different from a meson?
Quarkonium states are bound states of a quark-antiquark pair but so do the mesons. What is the difference between a quarkonium (e.g., charmonium, and bottomonium) and a meson then? Why use a separate ...
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Understanding some lines from 't Hooft's paper on large-N QCD in 1+1d
In 't Hooft's paper "A two-dimensional model for mesons", the author shows that two-dimensional (1+1) QCD in the large-N limit interestingly gives a theory of mesons. 't Hooft calculates the "mesonic ...
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349
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Comparison between $\rho^0$ and $J/\psi$ decay mode
Why must a hadronic decay of the $J/\psi$ meson include (at least) three gluons? Why is the decay mediated by a single gluon allowed for the $\rho^0$ meson?
6
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How are the 'physical' isospin zero states determined?
Consider the light mesons. Since $3 \times \bar{3} = 8 + 1$, the states should be grouped into $\mathfrak{su}(3)$ octets and singlets. In the case of the spin zero states (the pseudoscalars), the ...
- 103k
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vector mesons identified with positive parity
I have seen in some sources (like in https://arxiv.org/abs/1610.06090, page 11, footnote 11 but also in some few more) that vector mesons are assigned with positive parity $(J^P)=1^+$. In Particle ...
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Which mesons are possible?
That's probably a plain question but I wonder: Which mesons can exist? The only limitation I'm aware of is the charge (antiparticle+particle). Ok, finally also the color (anticolor+color) but I assume ...
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