Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron-antineutron Oscillations in the Trapping Box   We have reexamined the problem of $n-\bar n$ oscillations for ultra-cold
neutrons (UCN) confined within a trap. We have shown that the growth of the
$\bar n$ component with time is to a decent accuracy given by $P(\bar n)=
\epsilon^2_{n\bar n} t_Lt,$ where $\epsilon_{n\bar n}$ is the mixing parameter,
$t_L\sim 1 $ sec in the neutron propagation time between subsequent collisions
with the trap walls. Possible corrections to this law and open questions are
discussed.

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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio