Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Limits on the Mixing of Tau Neutrino to Heavy Neutrinos   Limits at 90 % c.l. on the square of the mixing strength |U_tau4|^2 between
nu_tau and a mostly isosinglet heavy neutrino with mass in the range 10-290
MeV/c^2 are reported. The results were derived using the negative result of a
search for neutral particles decaying into two electrons conducted by the CHARM
collaboration in a neutrino beam dump experiment. Upper limits ~10^-4 were
obtained for neutrino masses larger than 160 MeV/c^2.

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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
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The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph