Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How much space is left for a new family?   We perform an exploratory study of the allowed parameter range for the
CKM-like mixing of hypothetical quarks of a fourth generation. As experimental
constraints we use the tree-level determinations of the 3 $\times$ 3 CKM
elements and FCNC processes ($K$-, $D$-, $B_d$-, $B_s$-mixing and the decay $b
\to s \gamma$) under the assumption that the 4 $\times$ 4 CKM matrix is
unitary. For the FCNCs we use some simplifying assumptions concerning the QCD
corrections. Typically small mixing with the fourth family is favoured, but
contrary to expectation we find that also a quite large mixing with the 4th
family is not yet excluded.

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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
11
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: nlin
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The categories of this paper are: eess