Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solar neutrinos and grand unification   We consider the Grand Unification (GU) scenario for neutrino masses which is
based on the see-saw mechanism with the mass of the heaviest right handed (RH)
neutrino at the GU-scale: $M_3 \sim \Lambda_{GU}$, and on the quark-lepton
symmetry for fermions from the third generation. The scenario predicts for the
light neutrinos: $m_3 \sim (2 - 4) \cdot 10^{-3}$ eV and $m_2 \sim (0.3 - 3)
\cdot 10^{-5}$ eV (in the case of a linear mass hierarchy of the RH neutrinos
or/and in presence of the Planck scale suppressed non-renormalizable
operators). It also predicts large $\nu_e - \nu_{\mu}$ mixing: $~\sin^2
2\theta_{e\mu} \stackrel{_>}{_\sim} 0.2$. In this scenario the solar neutrinos
($\nu_{\odot}$) undergo both the \nue $\to$ \nutau resonance conversion in the
Sun and substantial \nue $\to$ \numu vacuum oscillations on the way from the
Sun to the Earth. The interplay of both effects enlarges the range of neutrino
parameters which solve the $\nu_{\odot}$-problem. In particular, $\nu_e -
\nu_{\tau}$ mixing angle can be as small as the corresponding quark mixing:
$\sin^2 2\theta_{e\tau} \geq (2~-~5) \cdot 10^{-4}$. The scenario predicts
peculiar (oscillatory) distortion of the boron neutrino energy spectrum and
seasonal variations of signals. Manifestations of these effects in the
Super-Kamiokande and SNO experiments are studied.

37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom