Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On flavor mixing by an effective Light-Cone QCD-Hamiltonian   The $\uparrow\downarrow$-model has produced the physical masses of all
flavor-asymmetric mesons like the $\pi^\pm$ or the $\rho^\pm$. Can the same
model also account for the flavor-symmetric mesons like the $\pi^0$ or the
$\rho^0$? -- By adjusting one parameter in a $5\times5$-matrix, the
$\pi$-$\eta$ degeneracy is lifted and the $\eta-\eta'$ splitting falls into the
right ball park. The isospin triplets for pions and rhos are caused the
mass-degeneracy of the up and down quark.

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The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat