Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The see-saw mechanism and heavy Majorana neutrino masses in an SO(10)
  model   We apply the see-saw mechanism and an SO(10) model to neutrino masses and
mixing in order to estimate the heavy Majorana masses. We discuss shortly the
decay modes of heavy Majorana neutrinos and calculate their contribution to the
lepton number violating processes \mu\to e\gamma, \tau\to\mu\gamma and \tau\to
e\gamma.

10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int