Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent BES measurements and the hadronic contribution to the QED vacuum
  polarization   We have updated our evaluation of the hadronic contribution to the running of
the QED fine structure constant using the recent precise measurements of the
e+e- annihilation at the center-of-mass (c.m.s.) energy region between 2.6 and
3.65 GeV performed by the BES collaboration. In the low energy region, around
the rho resonance, we include the recent measurements from the BABAR, CDM-2,
KLOE and SND collaborations. We obtain Delta alpha (5)_had (s) = 0.02750 +/-
0.00033 at s = m_Z^2.

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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: econ
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The categories of this paper are: astro-ph
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The categories of this paper are: cs
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The categories of this paper are: stat
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin