Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-Loop Neutrino Masses and the Solar Neutrino Problem   The addition of $m$ singlet right-handed neutrinos to the Standard Model
leads to radiatively generated mass corrections for the $SU(2)_L $ doublet
neutrinos. For those neutrinos which are massless at the tree level after this
addition, this implies a small mass generated at the two-loop level via
$W^{\pm}$ exchange. We calculate these mass corrections exactly by obtaining an
analytic form for the general case of $n$ doublets and $m$ singlets. As a
phenomenological application, we consider the $m=1$ case and examine the masses
and mixings of the doublet neutrinos which arise as a result of the two-loop
correction in the light of experimental data from two sources which may shed
light on the question of neutrino masses. These are(a) the neutrino detectors
reporting a solar neutrino deficit (and its resolution via
Mikheyev-Smirnov-Wolfenstein matter oscillations), and
  (b) the COBE satellite data on the non-zero angular variations of the cosmic
microwave background temperature (and its possible implications for hot dark
matter). Within the framework of the extension considered here, which leaves
the gauge group structure of the Standard Model intact, we show that it is
possible for neutrinos to acquire small masses naturally, with values which are
compatible with current theoretical bias and experimental data.

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The categories of this paper are: math
36
The categories of this paper are: cmp-lg
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: physics