Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quark Mixing, CKM Unitarity   In the Standard Model of elementary particles, quark-mixing is expressed in
terms of a 3 x 3 unitary matrix V, the so called Cabibbo-Kobayashi-Maskawa
(CKM) matrix. Significant unitarity checks are so far possible for the first
row of this matrix. This article reviews the experimental and theoretical
information on these matrix elements. On the experimental side, we find a 2.2
sigma to 2.7 sigma deviation from unitarity, which conflicts with the Standard
Model.

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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: physics
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga