Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical Constraints on the Vacuum Oscillation Solution to the Solar
  Neutrino Problem   The vacuum oscillation (VO) solution to the solar anomaly requires an
extremely small neutrino mass splitting, Delta m^2_{sol}\leq 10^{-10} eV^2. We
study under which circumstances this small splitting (whatever its origin) is
or is not spoiled by radiative corrections. The results depend dramatically on
the type of neutrino spectrum. If m_1^2 \sim m_2^2 \geq m_3^2, radiative
corrections always induce too large mass splittings. Moreover, if m_1 and m_2
have equal signs, the solar mixing angle is driven by the renormalization group
evolution to very small values, incompatible with the VO scenario (however, the
results could be consistent with the small-angle MSW scenario). If m_1 and m_2
have opposite signs, the results are analogous, except for some small (though
interesting) windows in which the VO solution may be natural with moderate
fine-tuning. Finally, for a hierarchical spectrum of neutrinos, m_1^2 << m_2^2
<< m_3^2, radiative corrections are not dangerous, and therefore this scenario
is the only plausible one for the VO solution.

15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio