Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hybrid MSW + VO Solution of the Solar Neutrino Problem in
  String-Motivated Unified Theories   It is shown that the hybrid MSW + VO solution of the solar neutrino problem,
according to which the solar nu_e undergo matter-enhanced transitions into
nu_mu, nu_tau in the Sun followed by long wave length (about 1.5 10^8 km) nu_e
-> nu_mu, nu_tau oscillations in vacuum between the Sun and the Earth, can
occur naturally in string-motivated grand unified theories. We consider the
supersymmetric version of a string-type SU(4)xSU(2)_LxSU(2)_R theory with
U(1)_X family symmetry, which was shown to successfully describe the charged
fermion masses and the quark mixing, and extend the earlier fermion mass
analysis to the neutrino sector. We show that the four oscillation parameters
Delta m_31^2, Delta m_21^2 and sin^2 2 theta_12, sin^2 2 theta_13,
characterising the combined matter-enhanced transitions and vacuum oscillations
of the solar nu_e, naturally get values in the ranges of the hybrid MSW + VO
solutions found recently.

14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an