Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Determination of V_ub at the Z-boson resonance   We show that the observation of energetic charged leptons from semileptonic
$b$ becays at the LEP and SLC $Z$--boson factories offers a unique opportunity
to measure the quark mixing matrix element $V_{ub}$. We present various
distributions of the $b$ decay products to show that the $b \to u$ decays can
be cleanly separated from the $b \to c$ decays, with a signal of $O(100)$
events per million $Z$ bosons produced.

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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: solv-int
3
The categories of this paper are: physics
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph