Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron - Mirror Neutron Oscillations: How Fast Might They Be?   We discuss the phenomenological implications of the neutron (n) oscillation
into the mirror neutron (n'), a hypothetical particle exactly degenerate in
mass with the neutron but sterile to normal matter. We show that the present
experimental data allow a maximal n-n' oscillation in vacuum with a
characteristic time $\tau$ much shorter than the neutron lifetime, in fact as
small as 1 sec. This phenomenon may manifest in neutron disappearance and
regeneration experiments perfectly accessible to present experimental
capabilities and may also have interesting astrophysical consequences, in
particular for the propagation of ultra high energy cosmic rays.

9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: cond-mat
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ex
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The categories of this paper are: q-fin