Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First Observation of the decay KL -> pi0 e e gamma   We report on the first observation of the decay KL -> pi0 ee gamma by the
KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an
estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma
branching ratio to be (2.34 +/- 0.35 +/- 0.13)x10^{-8}. Our data agree with
recent O(p^6) calculations in chiral perturbation theory that include
contributions from vector meson exchange through the parameter a_V. A fit was
made to the KL -> pi0 ee gamma data for a_V with the result -0.67 +/- 0.21 +/-
0.12, which is consistent with previous results from KTeV.

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The categories of this paper are: nucl-th
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
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The categories of this paper are: stat