Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The precise determination of Re(epsilon'/epsilon)   CP violation in the neutral kaon system is known to be dominated by the
mixing of K0 and anti-K0. Direct CP violation in the 2 pion decays of neutral
kaons has been a controversial subject over the last decade. A strong
experimental effort has been devoted to the precise measurement of the direct
CP violation parameter re(epsilon'/epsilon). After 10 years of detector
development, data collection and analysis, the NA48 experiment at CERN and the
KTeV experiment at Fermilab have now established direct CP violation as a fact.
Both KTeV and NA48 use the same experimental principle, measuring the double
ratio of long lived and short lived neutral kaons to two charged and two
neutral pions. However, their experimental and analysis techniques differ in
important ways, and I will extensively discuss the two approaches. I will also
present the latest results on epsilon'/epsilon from both experiments, which
were announced just a few months ago.

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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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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: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys