Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Strong CP problem with low-energy emergent QCD: The 4321 case   We analyze the strong CP problem and the implications for axion physics in
the context of $U_1$ vector leptoquark models, recently put forward as an
elegant solution to the hints of lepton flavor universality violation in
B-meson decays. It is shown that in minimal gauge models containing the $U_1$
as a gauge boson, the Peccei-Quinn solution of the strong CP problem requires
the introduction of two axions. Characteristic predictions for the associated
axions can be deduced from the model parameter space hinted by B-physics,
allowing the new axion sector to account for the dark matter of the Universe.
We also provide a specific ultraviolet completion of the axion sector that
connects the Peccei-Quinn mechanism to the generation of neutrino masses.

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The categories of this paper are: q-bio
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The categories of this paper are: econ
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: nlin
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The categories of this paper are: math-ph