Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can one of three righthanded neutrinos be light enough to produce a
  small LSND effect?   It is shown on the ground of a simple 6\times 6 neutrino mixing model that
one of three conventional sterile (righthanded) neutrinos, if light enough, may
be consistently used for explaining a {\it small} LSND effect. Then, it is
still considerably heavier than the three active (lefhanded) neutrinos, so that
a kind of {\it soft} seesaw mechanism can work. The usual condition that the
Majorana lefthanded component of the overall 6\times 6 neutrino mass matrix
ought to vanish, {\it implies} the smallness of active-neutrino masses versus
sterile-neutrino masses, when three mixing angles between both sorts of
neutrinos are small. In the presented model, the mass spectrum of active
neutrinos comes out roughly degenerate, lying in the range (5 - 7.5)\times
10^{-2} eV, {\it if} there is a {\it small} LSND effect with the amplitude of
the order 10^{-3} and with the mass-squared splitting \sim 1 eV^2.

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The categories of this paper are: cond-mat
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The categories of this paper are: stat
30
The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
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The categories of this paper are: astro-ph
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The categories of this paper are: math-ph
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The categories of this paper are: physics
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: chem-ph
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The categories of this paper are: nlin