Questions tagged [quantum-chromodynamics]
Quantum-ChromoDynamics (QCD) is the quantum field theory believed to describe the strong nuclear force.
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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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Deriving Euler-Lagrange Equations in Light-Front Quantization from the Heisenberg Equation
I'm delving into light-front quantization, with a focus on understanding the roles of good and bad fermions. Using Collins' formulation in Foundations of Perturbative QCD, we define the projectors as:
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How can dense quark matter stabilize wormholes?
I have read in several articles, such as
https://www.sciencedirect.com/science/article/abs/pii/S0577907323000266 and https://arxiv.org/abs/1403.0771 that dense quark matter can stabilize wormholes. ...
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QCD in Coulomb Gauge Kernel Expansion
I was re-reading the Hamiltonian QCD in Coulomb gauge section in Particle Physics and Introduction to Field Theory by T.D. Lee and I was trying to understand better the form of the Coulomb kernel that ...
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Why is it justified to focus on gauge transformations constant at spatial infinity in QCD instantons?
In the context of Yang-Mills theories and QCD instantons, much of the literature and conventional treatment hinges on the consideration of gauge transformations that remain constant at spatial ...
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Beyond sexaquarks?
There are some candidates for tetraquarks, pentaquarks or even now sexaquarks/hexaquarks. But, I wonder, what are the highest molecular quark states taking into account QCD? Are there heptaquarks, ...
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What is the speed of gluons inside a proton or neutron? [closed]
I have got the following answer to the above question from ChatGPT 4. Is this answer correct?
Any more new information that can added as an answer?
"The propagation speed of gluons inside a ...
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What does conservation of color charge mean for mixed states in QCD?
In quantum chromodynamics, in an interaction in which a quark and an anti-quark exchange a gluon, the color charge must be conserved. When we are talking about base states like $r\bar{b}$ it seems ...
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Schwinger proper-time representation of Feynman propagator in Coordinate space
I'm working on a QCDSR paper which calculates mass of $B$ meson in the present of external magnetic field.
the author works with Schwinger proper-time representation of Feynman propagator in momentum ...
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Has the mass of a proton been calculated from current quarks, through the renormalization process?
That's basically my question. Has the mass of the proton been calculated using QCD and the interactions between the current quarks? Perturbative methods obviously can't be used as they deal with ...
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No gluon interaction between nucleons
Given the spatial overlap of nucleon wave functions within the nucleus, why is the bonding of nucleons only the result of pion exchange and not of gluon interactions between quarks in different ...
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Is colour the conserved charge of global $SU(3)$ color symmetry?
Consider the Lagrangian consisting of three Dirac fields
$$ \mathcal{L} = \sum_{a=1}^3 \bar{\psi}_a ( i \gamma^\mu \partial_\mu - m ) \psi_a$$
where $a$ is an internal index labelling the colour ...
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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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Why does isospin symmetry survive chiral symmetry breaking?
In QCD there is a breaking of chiral symmetry such that, for the lightest quarks only, we have
$$\langle \overline{u} u \rangle = \langle \overline{d} d \rangle = \mathrm{const.}$$
where the constant ...
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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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